tests: remove legacy Topo class (fixes many pylint errors)

Signed-off-by: Christian Hopps <chopps@labn.net>

tests/topotests/all_protocol_startup/test_all_protocol_startup.py

@@ -34,8 +34,6 @@ import pytest
 import glob
 from time import sleep
 
-from lib.micronet_compat import Mininet, Topo
-
 from functools import partial
 
 pytestmark = [
@@ -50,6 +48,7 @@ pytestmark = [
 
 sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 from lib import topotest
+from lib.topogen import Topogen, get_topogen
 
 fatal_error = ""
 
@@ -61,24 +60,10 @@ fatal_error = ""
 #####################################################
 
 
-class NetworkTopo(Topo):
+def build_topo(tgen):
-    "All Protocol Startup Test"
+    router = tgen.add_router("r1")
-
-    def build(self, **_opts):
-
-        # Setup Routers
-        router = {}
-        #
-        # Setup Main Router
-        router[1] = topotest.addRouter(self, "r1")
-        #
-
-        # Setup Switches
-        switch = {}
-        #
     for i in range(0, 10):
-            switch[i] = self.addSwitch("sw%s" % i)
+        tgen.add_switch("sw%d" % i).add_link(router)
-            self.addLink(switch[i], router[1], intfName2="r1-eth%s" % i)
 
 
 #####################################################
@@ -89,21 +74,16 @@ class NetworkTopo(Topo):
 
 
 def setup_module(module):
-    global topo, net
     global fatal_error
 
     print("\n\n** %s: Setup Topology" % module.__name__)
     print("******************************************\n")
 
-    print("Cleanup old Mininet runs")
-    os.system("sudo mn -c > /dev/null 2>&1")
-    os.system("sudo rm /tmp/r* > /dev/null 2>&1")
-
     thisDir = os.path.dirname(os.path.realpath(__file__))
-    topo = NetworkTopo()
+    tgen = Topogen(build_topo, module.__name__)
+    tgen.start_topology()
 
-    net = Mininet(controller=None, topo=topo)
+    net = tgen.net
-    net.start()
 
     if net["r1"].get_routertype() != "frr":
         fatal_error = "Test is only implemented for FRR"
@@ -133,25 +113,22 @@ def setup_module(module):
         net["r%s" % i].loadConf("nhrpd", "%s/r%s/nhrpd.conf" % (thisDir, i))
         net["r%s" % i].loadConf("babeld", "%s/r%s/babeld.conf" % (thisDir, i))
         net["r%s" % i].loadConf("pbrd", "%s/r%s/pbrd.conf" % (thisDir, i))
-        net["r%s" % i].startRouter()
+        tgen.gears["r%s" % i].start()
 
     # For debugging after starting FRR daemons, uncomment the next line
     # CLI(net)
 
 
 def teardown_module(module):
-    global net
-
     print("\n\n** %s: Shutdown Topology" % module.__name__)
     print("******************************************\n")
-
+    tgen = get_topogen()
-    # End - Shutdown network
+    tgen.stop_topology()
-    net.stop()
 
 
 def test_router_running():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -172,7 +149,7 @@ def test_router_running():
 
 def test_error_messages_vtysh():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -228,7 +205,7 @@ def test_error_messages_vtysh():
 
 def test_error_messages_daemons():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -319,7 +296,7 @@ def test_error_messages_daemons():
 
 def test_converge_protocols():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -408,6 +385,7 @@ def test_converge_protocols():
 
 
 def route_get_nhg_id(route_str):
+    net = get_topogen().net
     output = net["r1"].cmd('vtysh -c "show ip route %s nexthop-group"' % route_str)
     match = re.search(r"Nexthop Group ID: (\d+)", output)
     assert match is not None, (
@@ -419,6 +397,7 @@ def route_get_nhg_id(route_str):
 
 
 def verify_nexthop_group(nhg_id, recursive=False, ecmp=0):
+    net = get_topogen().net
     # Verify NHG is valid/installed
     output = net["r1"].cmd('vtysh -c "show nexthop-group rib %d"' % nhg_id)
 
@@ -457,7 +436,7 @@ def verify_route_nexthop_group(route_str, recursive=False, ecmp=0):
 
 def test_nexthop_groups():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -606,7 +585,7 @@ def test_nexthop_groups():
 
 def test_rip_status():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -666,7 +645,7 @@ def test_rip_status():
 
 def test_ripng_status():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -733,7 +712,7 @@ def test_ripng_status():
 
 def test_ospfv2_interfaces():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -818,7 +797,7 @@ def test_ospfv2_interfaces():
 
 def test_isis_interfaces():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -884,7 +863,7 @@ def test_isis_interfaces():
 
 def test_bgp_summary():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1045,7 +1024,7 @@ def test_bgp_summary():
 
 def test_bgp_ipv6_summary():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1140,6 +1119,7 @@ def test_bgp_ipv6_summary():
 
 
 def test_nht():
+    net = get_topogen().net
     print("\n\n**** Test that nexthop tracking is at least nominally working ****\n")
 
     thisDir = os.path.dirname(os.path.realpath(__file__))
@@ -1188,7 +1168,7 @@ def test_nht():
 
 def test_bgp_ipv4():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1258,7 +1238,7 @@ def test_bgp_ipv4():
 
 def test_bgp_ipv6():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1327,7 +1307,7 @@ def test_bgp_ipv6():
 
 def test_route_map():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     if fatal_error != "":
         pytest.skip(fatal_error)
@@ -1370,7 +1350,7 @@ def test_route_map():
 
 def test_nexthop_groups_with_route_maps():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1467,7 +1447,7 @@ def test_nexthop_groups_with_route_maps():
 
 def test_nexthop_group_replace():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1500,7 +1480,7 @@ def test_nexthop_group_replace():
 
 def test_mpls_interfaces():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1569,7 +1549,7 @@ def test_mpls_interfaces():
 
 def test_shutdown_check_stderr():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":
@@ -1632,7 +1612,7 @@ def test_shutdown_check_stderr():
 
 def test_shutdown_check_memleak():
     global fatal_error
-    global net
+    net = get_topogen().net
 
     # Skip if previous fatal error condition is raised
     if fatal_error != "":

tests/topotests/bfd_topo2/test_bfd_topo2.py

@@ -46,28 +46,6 @@ from lib.topolog import logger
 pytestmark = [pytest.mark.bfdd, pytest.mark.bgpd, pytest.mark.ospfd]
 
 
-def build(self, *_args, **_opts):
-    "Build function"
-    tgen = get_topogen(self)
-
-    # Create 4 routers.
-    for routern in range(1, 5):
-        tgen.add_router("r{}".format(routern))
-
-    switch = tgen.add_switch("s1")
-    switch.add_link(tgen.gears["r1"])
-    switch.add_link(tgen.gears["r2"])
-
-    switch = tgen.add_switch("s2")
-    switch.add_link(tgen.gears["r2"])
-    switch.add_link(tgen.gears["r3"])
-
-    switch = tgen.add_switch("s3")
-    switch.add_link(tgen.gears["r2"])
-    switch.add_link(tgen.gears["r4"])
-
-
-
 def setup_module(mod):
     "Sets up the pytest environment"
     topodef = {
@@ -76,7 +54,6 @@ def setup_module(mod):
         "s3": ("r2", "r4"),
     }
     tgen = Topogen(topodef, mod.__name__)
-    # tgen = Topogen(build, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bfd_vrf_topo1/test_bfd_vrf_topo1.py

@@ -49,13 +49,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bfdd, pytest.mark.bgpd]
 
 
-class BFDTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
     # Create 4 routers
     for routern in range(1, 5):
         tgen.add_router("r{}".format(routern))
@@ -75,7 +69,7 @@ class BFDTopo(Topo):
 
 def setup_module(mod):
     "Sets up the pytest environment"
-    tgen = Topogen(BFDTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_aggregate_address_origin/test_bgp_aggregate-address_origin.py

@@ -50,10 +50,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -63,7 +60,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_aggregate_address_route_map/test_bgp_aggregate-address_route-map.py

@@ -53,10 +53,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -66,7 +63,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_aggregate_address_topo1/test_bgp_aggregate_address_topo1.py

@@ -45,10 +45,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class BgpAggregateAddressTopo1(Topo):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
 
+def build_topo(tgen):
     r1 = tgen.add_router("r1")
     r2 = tgen.add_router("r2")
     peer1 = tgen.add_exabgp_peer(
@@ -65,7 +63,7 @@ class BgpAggregateAddressTopo1(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(BgpAggregateAddressTopo1, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router = tgen.gears["r1"]

tests/topotests/bgp_aggregator_zero/test_bgp_aggregator_zero.py

@@ -43,10 +43,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class BgpAggregatorAsnZero(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     r1 = tgen.add_router("r1")
     peer1 = tgen.add_exabgp_peer(
         "peer1", ip="10.0.0.2", defaultRoute="via 10.0.0.1"
@@ -58,7 +55,7 @@ class BgpAggregatorAsnZero(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(BgpAggregatorAsnZero, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router = tgen.gears["r1"]

tests/topotests/bgp_as_allow_in/test_bgp_as_allow_in.py

@@ -94,16 +94,8 @@ NETWORK = {"ipv4": "2.2.2.2/32", "ipv6": "22:22::2/128"}
 NEXT_HOP_IP = {"ipv4": "Null0", "ipv6": "Null0"}
 
 
-class BGPALLOWASIN(Topo):
+def build_topo(tgen):
-    """
-    Test BGPALLOWASIN - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
     """Build function"""
-        tgen = get_topogen(self)
 
     # Building topology from json file
     build_topo_from_json(tgen, topo)
@@ -128,7 +120,7 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(BGPALLOWASIN, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_as_wide_bgp_identifier/test_bgp_as_wide_bgp_identifier.py

@@ -48,10 +48,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -62,7 +59,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_aspath_zero/test_bgp_aspath_zero.py

@@ -43,10 +43,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class BgpAggregatorAsnZero(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     r1 = tgen.add_router("r1")
     peer1 = tgen.add_exabgp_peer(
         "peer1", ip="10.0.0.2", defaultRoute="via 10.0.0.1"
@@ -58,7 +55,7 @@ class BgpAggregatorAsnZero(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(BgpAggregatorAsnZero, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router = tgen.gears["r1"]

tests/topotests/bgp_auth/test_bgp_auth.py

@@ -74,21 +74,9 @@ pytestmark = [pytest.mark.bgpd, pytest.mark.ospfd]
 
 class InvalidCLIError(Exception):
     """Raise when the CLI command is wrong"""
-
     pass
 
-
+def build_topo(tgen):
-class TemplateTopo(Topo):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # This function only purpose is to define allocation and relationship
-        # between routers, switches and hosts.
-        #
-        #
     # Create routers
     tgen.add_router("R1")
     tgen.add_router("R2")
@@ -143,7 +131,7 @@ class TemplateTopo(Topo):
 def setup_module(mod):
     "Sets up the pytest environment"
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
     tgen.start_topology()
 

tests/topotests/bgp_basic_functionality_topo1/test_bgp_basic_functionality.py

@@ -79,13 +79,6 @@ from lib.topolog import logger
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/bgp_basic_functionality.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global Variable
 KEEPALIVETIMER = 2
@@ -104,21 +97,6 @@ NETWORK = {
 }
 
 
-class CreateTopo(Topo):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -138,7 +116,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_basic_functionality.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_blackhole_community/test_bgp_blackhole_community.py

@@ -43,10 +43,7 @@ from lib.common_config import step
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 5):
         tgen.add_router("r{}".format(routern))
 
@@ -64,7 +61,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_comm_list_delete/test_bgp_comm-list_delete.py

@@ -48,10 +48,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -61,7 +58,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_communities_topo1/test_bgp_communities.py

@@ -69,14 +69,6 @@ from copy import deepcopy
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/bgp_communities.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Global variables
 BGP_CONVERGENCE = False
 ADDR_TYPES = check_address_types()
@@ -84,21 +76,6 @@ NETWORK = {"ipv4": "2.2.2.2/32", "ipv6": "22:22::2/128"}
 NEXT_HOP_IP = {}
 
 
-class BGPCOMMUNITIES(Topo):
-    """
-    Test BGPCOMMUNITIES - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -118,7 +95,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(BGPCOMMUNITIES, mod.__name__)
+    json_file = "{}/bgp_communities.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_communities_topo1/test_bgp_communities_topo2.py

@@ -73,14 +73,6 @@ from copy import deepcopy
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/bgp_communities_topo2.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Global variables
 BGP_CONVERGENCE = False
 ADDR_TYPES = check_address_types()
@@ -90,21 +82,6 @@ NETWORK = {
 }
 
 
-class BGPCOMMUNITIES(Topo):
-    """
-    Test BGPCOMMUNITIES - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -124,7 +101,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(BGPCOMMUNITIES, mod.__name__)
+    json_file = "{}/bgp_communities_topo2.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_community_alias/test_bgp-community-alias.py

@@ -43,10 +43,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
 
+def build_topo(tgen):
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -56,7 +54,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_community_change_update/test_bgp_community_change_update.py

@@ -62,10 +62,7 @@ from time import sleep
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     tgen.add_router("z1")
     tgen.add_router("y1")
     tgen.add_router("y2")
@@ -110,7 +107,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_conditional_advertisement/test_bgp_conditional_advertisement.py

@@ -142,10 +142,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class BgpConditionalAdvertisementTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     r1 = tgen.add_router("r1")
     r2 = tgen.add_router("r2")
     r3 = tgen.add_router("r3")
@@ -166,7 +163,7 @@ def setup_module(mod):
 
     logger.info("Running setup_module to create topology")
 
-    tgen = Topogen(BgpConditionalAdvertisementTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_default_afi_safi/test_bgp-default-afi-safi.py

@@ -50,10 +50,8 @@ from lib.common_config import step
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
 
+def build_topo(tgen):
     for routern in range(1, 5):
         tgen.add_router("r{}".format(routern))
 
@@ -65,7 +63,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_default_route/test_bgp_default-originate.py

@@ -41,10 +41,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -54,7 +51,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_default_route_route_map_match/test_bgp_default-originate_route-map_match.py

@@ -41,10 +41,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -54,7 +51,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_default_route_route_map_match2/test_bgp_default-originate_route-map_match2.py

@@ -44,10 +44,7 @@ from lib.common_config import step
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -57,7 +54,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_default_route_route_map_match_set/test_bgp_default-originate_route-map_match_set.py

@@ -43,10 +43,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -56,7 +53,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_default_route_route_map_set/test_bgp_default-originate_route-map_set.py

@@ -41,10 +41,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -54,7 +51,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_disable_addpath_rx/r1/bgpd.conf

@@ -1,7 +1,9 @@
 !
 router bgp 65001
+ timers 3 10
  no bgp ebgp-requires-policy
  neighbor 192.168.1.2 remote-as external
+ neighbor 192.168.1.2 timers connect 5
  address-family ipv4 unicast
   neighbor 192.168.1.2 disable-addpath-rx
  exit-address-family

tests/topotests/bgp_disable_addpath_rx/r2/bgpd.conf

@@ -1,8 +1,12 @@
 router bgp 65002
+ timers 3 10
  no bgp ebgp-requires-policy
  neighbor 192.168.1.1 remote-as external
+ neighbor 192.168.1.1 timers connect 5
  neighbor 192.168.2.3 remote-as external
+ neighbor 192.168.2.3 timers connect 5
  neighbor 192.168.2.4 remote-as external
+ neighbor 192.168.2.4 timers connect 5
  address-family ipv4 unicast
   neighbor 192.168.1.1 addpath-tx-all-paths
  exit-address-family

tests/topotests/bgp_disable_addpath_rx/r3/bgpd.conf

@@ -1,6 +1,8 @@
 router bgp 65003
+ timers 3 10
  no bgp ebgp-requires-policy
  neighbor 192.168.2.2 remote-as external
+ neighbor 192.168.2.2 timers connect 5
  address-family ipv4 unicast
   redistribute connected
  exit-address-family

tests/topotests/bgp_disable_addpath_rx/r4/bgpd.conf

@@ -1,6 +1,8 @@
 router bgp 65004
+ timers 3 10
  no bgp ebgp-requires-policy
  neighbor 192.168.2.2 remote-as external
+ neighbor 192.168.2.2 timers connect 5
  address-family ipv4 unicast
   redistribute connected
  exit-address-family

tests/topotests/bgp_disable_addpath_rx/test_disable_addpath_rx.py

@@ -25,7 +25,6 @@ Test if AddPath RX direction is not negotiated via AddPath capability.
 import os
 import sys
 import json
-import time
 import pytest
 import functools
 
@@ -35,17 +34,12 @@ sys.path.append(os.path.join(CWD, "../"))
 # pylint: disable=C0413
 from lib import topotest
 from lib.topogen import Topogen, TopoRouter, get_topogen
-from lib.topolog import logger
-from mininet.topo import Topo
 from lib.common_config import step
 
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 5):
         tgen.add_router("r{}".format(routern))
 
@@ -60,7 +54,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_distance_change/test_bgp_distance_change.py

@@ -52,10 +52,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -65,7 +62,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_ebgp_common_subnet_nexthop_unchanged/test_bgp-ebgp-common-subnet-nexthop-unchanged.py

@@ -54,10 +54,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
 
+def build_topo(tgen):
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -68,7 +66,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_ebgp_requires_policy/test_bgp_ebgp_requires_policy.py

@@ -60,10 +60,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
 
+def build_topo(tgen):
     for routern in range(1, 7):
         tgen.add_router("r{}".format(routern))
 
@@ -84,7 +82,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_ecmp_topo1/test_bgp_ecmp_topo1.py

@@ -58,23 +58,17 @@ total_ebgp_peers = 20
 #####################################################
 
 
-class BGPECMPTopo1(Topo):
+def build_topo(tgen):
-    "BGP ECMP Topology 1"
-
-    def build(self, **_opts):
-        tgen = get_topogen(self)
-
-        # Create the BGP router
     router = tgen.add_router("r1")
 
     # Setup Switches - 1 switch per 5 peering routers
-        for swNum in range(1, (total_ebgp_peers + 4) / 5 + 1):
+    for swNum in range(1, (total_ebgp_peers + 4) // 5 + 1):
         switch = tgen.add_switch("s{}".format(swNum))
         switch.add_link(router)
 
     # Add 'total_ebgp_peers' number of eBGP ExaBGP neighbors
     for peerNum in range(1, total_ebgp_peers + 1):
-            swNum = (peerNum - 1) / 5 + 1
+        swNum = (peerNum - 1) // 5 + 1
 
         peer_ip = "10.0.{}.{}".format(swNum, peerNum + 100)
         peer_route = "via 10.0.{}.1".format(swNum)
@@ -94,7 +88,7 @@ class BGPECMPTopo1(Topo):
 
 
 def setup_module(module):
-    tgen = Topogen(BGPECMPTopo1, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     # Starting Routers

tests/topotests/bgp_ecmp_topo2/test_ebgp_ecmp_topo2.py

@@ -71,14 +71,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/ebgp_ecmp_topo2.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NEXT_HOPS = {"ipv4": [], "ipv6": []}
@@ -89,21 +81,6 @@ NEXT_HOP_IP = {"ipv4": "10.0.0.1", "ipv6": "fd00::1"}
 BGP_CONVERGENCE = False
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment.
@@ -125,7 +102,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/ebgp_ecmp_topo2.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Starting topology, create tmp files which are loaded to routers
     #  to start deamons and then start routers

tests/topotests/bgp_ecmp_topo2/test_ibgp_ecmp_topo2.py

@@ -71,14 +71,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/ibgp_ecmp_topo2.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NEXT_HOPS = {"ipv4": [], "ipv6": []}
@@ -89,21 +81,6 @@ NEXT_HOP_IP = {"ipv4": "10.0.0.1", "ipv6": "fd00::1"}
 BGP_CONVERGENCE = False
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment.
@@ -125,7 +102,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/ibgp_ecmp_topo2.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Starting topology, create tmp files which are loaded to routers
     #  to start deamons and then start routers

tests/topotests/bgp_ecmp_topo3/test_ibgp_ecmp_topo3.py

@@ -40,7 +40,7 @@ sys.path.append(os.path.join(CWD, "../../"))
 # pylint: disable=C0413
 # Import topogen and topotest helpers
 from lib.topogen import Topogen, get_topogen
-from mininet.topo import Topo
+from lib import topojson
 
 from lib.common_config import (
     start_topology,
@@ -63,15 +63,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/ibgp_ecmp_topo3.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Global variables
 NEXT_HOPS = {"ipv4": [], "ipv6": []}
 NETWORK = {"ipv4": "192.168.1.10/32", "ipv6": "fd00:0:0:1::10/128"}
@@ -79,45 +70,20 @@ NEXT_HOP_IP = {"ipv4": "10.0.0.1", "ipv6": "fd00::1"}
 BGP_CONVERGENCE = False
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment.
 
     * `mod`: module name
     """
-    global NEXT_HOPS, INTF_LIST_R3, INTF_LIST_R2, TEST_STATIC
     global ADDR_TYPES
 
     testsuite_run_time = time.asctime(time.localtime(time.time()))
     logger.info("Testsuite start time: {}".format(testsuite_run_time))
     logger.info("=" * 40)
 
-    logger.info("Running setup_module to create topology")
+    tgen = topojson.setup_module_from_json(mod.__file__)
-
+    topo = tgen.json_topo
-    # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
-
-    # Starting topology, create tmp files which are loaded to routers
-    #  to start deamons and then start routers
-    start_topology(tgen)
-
-    # Creating configuration from JSON
-    build_config_from_json(tgen, topo)
 
     # Don't run this test if we have any failure.
     if tgen.routers_have_failure():
@@ -136,18 +102,7 @@ def setup_module(mod):
 
 
 def teardown_module():
-    """
+    get_topogen().stop_topology()
-    Teardown the pytest environment.
-
-    * `mod`: module name
-    """
-
-    logger.info("Running teardown_module to delete topology")
-
-    tgen = get_topogen()
-
-    # Stop toplogy and Remove tmp files
-    tgen.stop_topology()
 
 
 def static_or_nw(tgen, topo, tc_name, test_type, dut):
@@ -221,12 +176,11 @@ def static_or_nw(tgen, topo, tc_name, test_type, dut):
 
 
 @pytest.mark.parametrize("test_type", ["redist_static"])
-def test_ecmp_fast_convergence(request, test_type):
+def test_ecmp_fast_convergence(request, test_type, tgen, topo):
     """This test is to verify bgp fast-convergence cli functionality"""
 
     tc_name = request.node.name
     write_test_header(tc_name)
-    tgen = get_topogen()
 
     # Verifying RIB routes
     dut = "r3"

tests/topotests/bgp_evpn_mh/test_evpn_mh.py

@@ -62,7 +62,7 @@ pytestmark = [pytest.mark.bgpd, pytest.mark.pimd]
 #####################################################
 
 
-class NetworkTopo(Topo):
+def build_topo(tgen):
     """
     EVPN Multihoming Topology -
     1. Two level CLOS
@@ -71,11 +71,6 @@ class NetworkTopo(Topo):
     4. Two dual attached hosts per-rack - hostdx1, hostdx2
     """
 
-    def build(self, **_opts):
-        "Build function"
-
-        tgen = get_topogen(self)
-
     tgen.add_router("spine1")
     tgen.add_router("spine2")
     tgen.add_router("torm11")
@@ -371,7 +366,7 @@ def config_hosts(tgen, hosts):
 
 def setup_module(module):
     "Setup topology"
-    tgen = Topogen(NetworkTopo, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     krel = platform.release()

tests/topotests/bgp_evpn_overlay_index_gateway/test_bgp_evpn_overlay_index_gateway.py

@@ -88,13 +88,7 @@ HOST_SUFFIX = {'host1': '1', 'host2': '2'}
 TRIGGERS = ["base", "no_rt5", "no_rt2"]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    """Test topology builder"""
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
     # This function only purpose is to define allocation and relationship
     # between routers and add links.
 
@@ -123,7 +117,7 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
 
     kernelv = platform.release()

tests/topotests/bgp_evpn_rt5/test_bgp_evpn.py

@@ -48,12 +48,9 @@ from lib.micronet_compat import Topo
 
 pytestmark = [pytest.mark.bgpd]
 
-class BGPEVPNTopo(Topo):
-    "Test topology builder"
 
-    def build(self, *_args, **_opts):
+def build_topo(tgen):
     "Build function"
-        tgen = get_topogen(self)
 
     tgen.add_router("r1")
     tgen.add_router("r2")
@@ -72,7 +69,7 @@ class BGPEVPNTopo(Topo):
 def setup_module(mod):
     "Sets up the pytest environment"
 
-    tgen = Topogen(BGPEVPNTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_evpn_vxlan_topo1/test_bgp_evpn_vxlan.py

@@ -49,12 +49,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd, pytest.mark.ospfd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # This function only purpose is to define allocation and relationship
     # between routers, switches and hosts.
@@ -91,7 +87,7 @@ class TemplateTopo(Topo):
 def setup_module(mod):
     "Sets up the pytest environment"
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
     tgen.start_topology()
 

tests/topotests/bgp_features/test_bgp_features.py

@@ -56,16 +56,18 @@ pytestmark = [pytest.mark.bgpd, pytest.mark.ospfd]
 #####################################################
 
 
-class BGPFeaturesTopo1(Topo):
+def build_topo(tgen):
-    "BGP Features Topology 1"
-
-    def build(self, **_opts):
-        tgen = get_topogen(self)
-
-        # Create the routers
     for rtrNum in range(1, 6):
         tgen.add_router("r{}".format(rtrNum))
 
+    # create ExaBGP peers
+    for peer_num in range(1, 5):
+        tgen.add_exabgp_peer(
+            "peer{}".format(peer_num),
+            ip="192.168.101.{}".format(peer_num + 2),
+            defaultRoute="via 192.168.101.1",
+        )
+
     # Setup Switches and connections
     for swNum in range(1, 11):
         tgen.add_switch("sw{}".format(swNum))
@@ -91,6 +93,12 @@ class BGPFeaturesTopo1(Topo):
     tgen.gears["r2"].add_link(tgen.gears["sw5"])
     tgen.gears["r5"].add_link(tgen.gears["sw5"])
 
+    # Add ExaBGP peers to sw4
+    tgen.gears["peer1"].add_link(tgen.gears["sw4"])
+    tgen.gears["peer2"].add_link(tgen.gears["sw4"])
+    tgen.gears["peer3"].add_link(tgen.gears["sw4"])
+    tgen.gears["peer4"].add_link(tgen.gears["sw4"])
+
 
 #####################################################
 #
@@ -100,7 +108,7 @@ class BGPFeaturesTopo1(Topo):
 
 
 def setup_module(module):
-    tgen = Topogen(BGPFeaturesTopo1, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     # Starting Routers

tests/topotests/bgp_flowspec/test_bgp_flowspec_topo.py

@@ -82,13 +82,7 @@ pytestmark = [pytest.mark.bgpd]
 #####################################################
 
 
-class BGPFLOWSPECTopo1(Topo):
+def build_topo(tgen):
-    "BGP EBGP Flowspec Topology 1"
-
-    def build(self, **_opts):
-        tgen = get_topogen(self)
-
-        # Setup Routers
     tgen.add_router("r1")
 
     # Setup Control Path Switch 1. r1-eth0
@@ -110,7 +104,7 @@ class BGPFLOWSPECTopo1(Topo):
 
 
 def setup_module(module):
-    tgen = Topogen(BGPFLOWSPECTopo1, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
 
     tgen.start_topology()
     # check for zebra capability

tests/topotests/bgp_gr_functionality_topo1/test_bgp_gr_functionality_topo1.py

@@ -142,15 +142,6 @@ from lib.common_config import (
 pytestmark = [pytest.mark.bgpd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_gr_topojson_topo1.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    logger.info("Could not read file:", jsonFile)
-
-
 # Global variables
 NEXT_HOP_IP = {"ipv4": "192.168.1.10", "ipv6": "fd00:0:0:1::10"}
 NEXT_HOP_IP_1 = {"ipv4": "192.168.0.1", "ipv6": "fd00::1"}
@@ -160,28 +151,6 @@ GR_RESTART_TIMER = 20
 PREFERRED_NEXT_HOP = "link_local"
 
 
-class GenerateTopo(Topo):
-    """
-    Test topology builder
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # This function only purpose is to create topology
-        # as defined in input json file.
-        #
-        # Create topology (setup module)
-        # Creating 2 routers topology, r1, r2in IBGP
-        # Bring up topology
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -203,7 +172,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(GenerateTopo, mod.__name__)
+    json_file = "{}/bgp_gr_topojson_topo1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_gr_functionality_topo2/test_bgp_gr_functionality_topo2.py

@@ -141,14 +141,6 @@ from lib.common_config import (
 pytestmark = [pytest.mark.bgpd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_gr_topojson_topo2.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    logger.info("Could not read file:", jsonFile)
-
 # Global variables
 BGP_CONVERGENCE = False
 GR_RESTART_TIMER = 5
@@ -159,28 +151,6 @@ NEXT_HOP_4 = ["192.168.1.1", "192.168.4.2"]
 NEXT_HOP_6 = ["fd00:0:0:1::1", "fd00:0:0:4::2"]
 
 
-class GenerateTopo(Topo):
-    """
-    Test topology builder
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # This function only purpose is to create topology
-        # as defined in input json file.
-        #
-        # Create topology (setup module)
-        # Creating 2 routers topology, r1, r2in IBGP
-        # Bring up topology
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -202,7 +172,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(GenerateTopo, mod.__name__)
+    json_file = "{}/bgp_gr_topojson_topo2.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_gshut/test_bgp_gshut.py

@@ -78,10 +78,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 6):
         tgen.add_router("r{}".format(routern))
 
@@ -110,7 +107,7 @@ def _run_cmd_and_check(router, cmd, results_file, retries=100, intvl=0.5):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_gshut_topo1/test_ebgp_gshut_topo1.py

@@ -75,17 +75,10 @@ from lib.bgp import (
 )
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/ebgp_gshut_topo1.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    logger.info("Could not read file:", jsonFile)
-
 # Global variables
 NETWORK = {"ipv4": "100.0.10.1/32", "ipv6": "1::1/128"}
 NEXT_HOP_IP_1 = {"ipv4": "10.0.2.1", "ipv6": "fd00:0:0:1::1"}
@@ -94,28 +87,6 @@ PREFERRED_NEXT_HOP = "link_local"
 BGP_CONVERGENCE = False
 
 
-class GenerateTopo(Topo):
-    """
-    Test topology builder
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # This function only purpose is to create topology
-        # as defined in input json file.
-        #
-        # Create topology (setup module)
-        # Creating 2 routers topology, r1, r2in IBGP
-        # Bring up topology
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -137,7 +108,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(GenerateTopo, mod.__name__)
+    json_file = "{}/ebgp_gshut_topo1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_gshut_topo1/test_ibgp_gshut_topo1.py

@@ -78,14 +78,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/ibgp_gshut_topo1.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    logger.info("Could not read file:", jsonFile)
-
 # Global variables
 NETWORK = {"ipv4": "100.0.10.1/32", "ipv6": "1::1/128"}
 NEXT_HOP_IP_1 = {"ipv4": "10.0.3.1", "ipv6": "fd00:0:0:3::1"}
@@ -94,28 +86,6 @@ PREFERRED_NEXT_HOP = "link_local"
 BGP_CONVERGENCE = False
 
 
-class GenerateTopo(Topo):
-    """
-    Test topology builder
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # This function only purpose is to create topology
-        # as defined in input json file.
-        #
-        # Create topology (setup module)
-        # Creating 2 routers topology, r1, r2in IBGP
-        # Bring up topology
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -137,7 +107,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(GenerateTopo, mod.__name__)
+    json_file = "{}/ibgp_gshut_topo1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ebgp_ibgp_nbr.py

@@ -39,7 +39,6 @@ sys.path.append(os.path.join(CWD, "../../"))
 # pylint: disable=C0413
 # Import topogen and topotest helpers
 from lib.topogen import Topogen, get_topogen
-from mininet.topo import Topo
 
 from lib.common_config import (
     start_topology,
@@ -66,13 +65,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 
 # Global variables
 topo = None
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/rfc5549_ebgp_ibgp_nbr.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NETWORK = {
@@ -121,21 +113,6 @@ unchange is configure on EBGP peers
  """
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """Set up the pytest environment."""
 
@@ -147,7 +124,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/rfc5549_ebgp_ibgp_nbr.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Starting topology, create tmp files which are loaded to routers
     #  to start deamons and then start routers

tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ebgp_nbr.py

@@ -40,7 +40,6 @@ sys.path.append(os.path.join(CWD, "../../"))
 # pylint: disable=C0413
 # Import topogen and topotest helpers
 from lib.topogen import Topogen, get_topogen
-from mininet.topo import Topo
 
 from lib.common_config import (
     start_topology,
@@ -71,13 +70,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 
 # Global variables
 topo = None
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/rfc5549_ebgp_nbr.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NETWORK = {
@@ -137,21 +129,6 @@ TC32. Verify IPv4 route received with IPv6 nexthop can be advertised to
  """
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """Set up the pytest environment."""
     global topo, ADDR_TYPES
@@ -163,7 +140,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/rfc5549_ebgp_nbr.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Starting topology, create tmp files which are loaded to routers
     #  to start deamons and then start routers

tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ebgp_unnumbered_nbr.py

@@ -37,7 +37,6 @@ sys.path.append(os.path.join(CWD, "../"))
 sys.path.append(os.path.join(CWD, "../../"))
 
 from lib.topogen import Topogen, get_topogen
-from mininet.topo import Topo
 
 from lib.common_config import (
     write_test_header,
@@ -62,13 +61,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 
 # Global variables
 topo = None
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/rfc5549_ebgp_unnumbered_nbr.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NO_OF_RTES = 2
@@ -124,21 +116,6 @@ shut / no shut of nexthop and BGP peer interfaces
  """
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """Set up the pytest environment."""
     global topo, ADDR_TYPES
@@ -150,7 +127,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/rfc5549_ebgp_unnumbered_nbr.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Starting topology, create tmp files which are loaded to routers
     #  to start deamons and then start routers

tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ibgp_nbr.py

@@ -39,7 +39,6 @@ sys.path.append(os.path.join(CWD, "../../"))
 # pylint: disable=C0413
 # Import topogen and topotest helpers
 from lib.topogen import Topogen, get_topogen
-from mininet.topo import Topo
 
 from lib.common_config import (
     start_topology,
@@ -67,13 +66,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 
 # Global variables
 topo = None
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/rfc5549_ibgp_nbr.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NETWORK = {
@@ -121,21 +113,6 @@ TESTCASES = """
  """
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """Set up the pytest environment."""
 
@@ -147,7 +124,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/rfc5549_ibgp_nbr.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Starting topology, create tmp files which are loaded to routers
     #  to start deamons and then start routers

tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ibgp_unnumbered_nbr.py

@@ -38,7 +38,6 @@ sys.path.append(os.path.join(CWD, "../../"))
 # pylint: disable=C0413
 # Import topogen and topotest helpers
 from lib.topogen import Topogen, get_topogen
-from mininet.topo import Topo
 
 from lib.common_config import (
     start_topology,
@@ -58,13 +57,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 
 # Global variables
 topo = None
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/rfc5549_ibgp_unnumbered_nbr.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 
 # Global variables
@@ -107,21 +99,6 @@ TESTCASES = """
  """
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder.
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """Set up the pytest environment."""
 
@@ -133,7 +110,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/rfc5549_ibgp_unnumbered_nbr.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Starting topology, create tmp files which are loaded to routers
     #  to start deamons and then start routers

tests/topotests/bgp_ipv6_rtadv/test_bgp_ipv6_rtadv.py

@@ -49,12 +49,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class BGPIPV6RTADVTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # Create 2 routers.
     tgen.add_router("r1")
@@ -67,7 +63,7 @@ class BGPIPV6RTADVTopo(Topo):
 
 def setup_module(mod):
     "Sets up the pytest environment"
-    tgen = Topogen(BGPIPV6RTADVTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_l3vpn_to_bgp_direct/customize.py

@@ -94,12 +94,8 @@ CWD = os.path.dirname(os.path.realpath(__file__))
 TEST = os.path.basename(CWD)
 
 
-class ThisTestTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # This function only purpose is to define allocation and relationship
     # between routers, switches and hosts.

tests/topotests/bgp_l3vpn_to_bgp_vrf/customize.py

@@ -95,12 +95,8 @@ CWD = os.path.dirname(os.path.realpath(__file__))
 TEST = os.path.basename(CWD)
 
 
-class ThisTestTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # This function only purpose is to define allocation and relationship
     # between routers, switches and hosts.

tests/topotests/bgp_large_community/test_bgp_large_community_topo_1.py

@@ -81,13 +81,6 @@ CWD = os_path.dirname(os_path.realpath(__file__))
 sys.path.append(os_path.join(CWD, "../"))
 sys.path.append(os_path.join(CWD, "../lib/"))
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_large_community_topo_1.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json_load(topoJson)
-except IOError:
-    logger.info("Could not read file:", jsonFile)
 
 # Global variables
 bgp_convergence = False
@@ -124,22 +117,6 @@ STANDARD_COMM = {
 }
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder
-
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -159,7 +136,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_large_community_topo_1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_large_community/test_bgp_large_community_topo_2.py

@@ -97,39 +97,16 @@ from lib.topolog import logger
 from lib.bgp import verify_bgp_convergence, create_router_bgp, clear_bgp_and_verify
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_large_community_topo_2.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Global variables
 bgp_convergence = False
 
 NETWORKS = {"ipv4": ["200.50.2.0/32"], "ipv6": ["1::1/128"]}
 
 
-class GenerateTopo(Topo):
-    """
-    Test topology builder
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -149,7 +126,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(GenerateTopo, mod.__name__)
+    json_file = "{}/bgp_large_community_topo_2.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_link_bw_ip/test_bgp_linkbw_ip.py

@@ -66,13 +66,8 @@ this scenario, the servers are also routers as they have to announce
 anycast IP (VIP) addresses via BGP.
 """
 
-
+def build_topo(tgen):
-class BgpLinkBwTopo(Topo):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # Create 10 routers - 1 super-spine, 2 spines, 3 leafs
     # and 4 servers
@@ -121,7 +116,7 @@ class BgpLinkBwTopo(Topo):
 
 def setup_module(mod):
     "Sets up the pytest environment"
-    tgen = Topogen(BgpLinkBwTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_listen_on_multiple_addresses/test_bgp_listen_on_multiple_addresses.py

@@ -67,27 +67,12 @@ LISTEN_ADDRESSES = {
 }
 
 
-# Reads data from JSON File for topology and configuration creation.
-jsonFile = "{}/bgp_listen_on_multiple_addresses.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
-
-class TemplateTopo(Topo):
-    "Topology builder."
-
-    def build(self, *_args, **_opts):
-        "Defines the allocation and relationship between routers and switches."
-        tgen = get_topogen(self)
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     "Sets up the test environment."
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    json_file = "{}/bgp_listen_on_multiple_addresses.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
 
     # Adds extra parameters to bgpd so they listen for connections on specific
     # multiple addresses.

tests/topotests/bgp_local_as_private_remove/test_bgp_local_as_private_remove.py

@@ -46,10 +46,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 5):
         tgen.add_router("r{}".format(routern))
 
@@ -63,7 +60,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_lu_topo1/test_bgp_lu.py

@@ -62,12 +62,8 @@ pytestmark = [pytest.mark.bgpd]
 # +-----+                +-----+                 +-----+
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # This function only purpose is to define allocation and relationship
     # between routers, switches and hosts.
@@ -92,7 +88,7 @@ class TemplateTopo(Topo):
 def setup_module(mod):
     "Sets up the pytest environment"
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
     tgen.start_topology()
 

tests/topotests/bgp_maximum_prefix_invalid_update/test_bgp_maximum_prefix_invalid_update.py

@@ -50,10 +50,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -63,7 +60,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_maximum_prefix_out/test_bgp_maximum_prefix_out.py

@@ -46,10 +46,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -59,7 +56,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_minimum_holdtime/test_bgp_minimum_holdtime.py

@@ -41,10 +41,7 @@ from mininet.topo import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -54,7 +51,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_multi_vrf_topo1/test_bgp_multi_vrf_topo1.py

@@ -145,15 +145,9 @@ from lib.bgp import (
 )
 from lib.topojson import build_topo_from_json, build_config_from_json
 
-pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/bgp_multi_vrf_topo1.json".format(CWD)
 
-try:
+pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
-    with open(jsonFile, "r") as topoJson:
+
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NETWORK1_1 = {"ipv4": "1.1.1.1/32", "ipv6": "1::1/128"}
@@ -185,21 +179,6 @@ LOOPBACK_2 = {
 }
 
 
-class CreateTopo(Topo):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -222,7 +201,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_multi_vrf_topo1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_multi_vrf_topo2/test_bgp_multi_vrf_topo2.py

@@ -105,14 +105,6 @@ from lib.topojson import build_config_from_json, build_topo_from_json
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/bgp_multi_vrf_topo2.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 NETWORK1_1 = {"ipv4": "1.1.1.1/32", "ipv6": "1::1/128"}
@@ -139,21 +131,6 @@ HOLDDOWNTIMER = 3
 PREFERRED_NEXT_HOP = "link_local"
 
 
-class CreateTopo(Topo):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -176,7 +153,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_multi_vrf_topo2.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_multiview_topo1/test_bgp_multiview_topo1.py

@@ -74,8 +74,7 @@ from functools import partial
 
 sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 from lib import topotest
-from lib.micronet_compat import Mininet
+from lib.topogen import get_topogen, Topogen
-from lib.micronet_compat import Topo
 
 
 pytestmark = [pytest.mark.bgpd]
@@ -91,38 +90,28 @@ fatal_error = ""
 #####################################################
 
 
-class NetworkTopo(Topo):
+def build_topo(tgen):
-    "BGP Multiview Topology 1"
-
-    def build(self, **_opts):
-
-        exabgpPrivateDirs = ["/etc/exabgp", "/var/run/exabgp", "/var/log"]
-
     # Setup Routers
-        router = {}
+    router = tgen.add_router("r1")
-        for i in range(1, 2):
-            router[i] = topotest.addRouter(self, "r%s" % i)
 
     # Setup Provider BGP peers
     peer = {}
     for i in range(1, 9):
-            peer[i] = self.addHost(
+        peer[i] = tgen.add_exabgp_peer(
             "peer%s" % i,
             ip="172.16.1.%s/24" % i,
-                defaultRoute="via 172.16.1.254",
+            defaultRoute="via 172.16.1.254"
-                privateDirs=exabgpPrivateDirs,
         )
 
-        # Setup Switches
-        switch = {}
     # First switch is for a dummy interface (for local network)
-        switch[0] = self.addSwitch("sw0")
+    switch = tgen.add_switch("sw0")
-        self.addLink(switch[0], router[1], intfName2="r1-stub")
+    switch.add_link(router, nodeif="r1-stub")
+
     # Second switch is for connection to all peering routers
-        switch[1] = self.addSwitch("sw1")
+    switch = tgen.add_switch("sw1")
-        self.addLink(switch[1], router[1], intfName2="r1-eth0")
+    switch.add_link(router, nodeif="r1-eth0")
     for j in range(1, 9):
-            self.addLink(switch[1], peer[j], intfName2="peer%s-eth0" % j)
+        switch.add_link(peer[j], nodeif="peer%s-eth0" % j)
 
 
 #####################################################
@@ -133,87 +122,43 @@ class NetworkTopo(Topo):
 
 
 def setup_module(module):
-    global topo, net
-
-    print("\n\n** %s: Setup Topology" % module.__name__)
-    print("******************************************\n")
-
-    print("Cleanup old Mininet runs")
-    os.system("sudo mn -c > /dev/null 2>&1")
-
     thisDir = os.path.dirname(os.path.realpath(__file__))
-    topo = NetworkTopo()
+    tgen = Topogen(build_topo, module.__name__)
-
+    tgen.start_topology()
-    net = Mininet(controller=None, topo=topo)
-    net.start()
 
     # Starting Routers
-    for i in range(1, 2):
+    router = tgen.net["r1"]
-        net["r%s" % i].loadConf("zebra", "%s/r%s/zebra.conf" % (thisDir, i))
+    router.loadConf("zebra", "%s/r1/zebra.conf" % thisDir)
-        net["r%s" % i].loadConf("bgpd", "%s/r%s/bgpd.conf" % (thisDir, i))
+    router.loadConf("bgpd", "%s/r1/bgpd.conf" % thisDir)
-        net["r%s" % i].startRouter()
+    tgen.gears["r1"].start()
 
     # Starting PE Hosts and init ExaBGP on each of them
-    print("*** Starting BGP on all 8 Peers")
+    peer_list = tgen.exabgp_peers()
-    for i in range(1, 9):
+    for pname, peer in peer_list.items():
-        net["peer%s" % i].cmd("cp %s/exabgp.env /etc/exabgp/exabgp.env" % thisDir)
+        peer_dir = os.path.join(thisDir, pname)
-        net["peer%s" % i].cmd("cp %s/peer%s/* /etc/exabgp/" % (thisDir, i))
+        env_file = os.path.join(thisDir, "exabgp.env")
-        net["peer%s" % i].cmd("chmod 644 /etc/exabgp/*")
+        peer.start(peer_dir, env_file)
-        net["peer%s" % i].cmd("chmod 755 /etc/exabgp/*.py")
-        net["peer%s" % i].cmd("chown -R exabgp:exabgp /etc/exabgp")
-        net["peer%s" % i].cmd("exabgp -e /etc/exabgp/exabgp.env /etc/exabgp/exabgp.cfg")
-        print("peer%s" % i),
-    print("")
-
-    # For debugging after starting FRR daemons, uncomment the next line
-    # CLI(net)
 
 
 def teardown_module(module):
-    global net
+    tgen = get_topogen()
-
+    tgen.stop_topology()
-    print("\n\n** %s: Shutdown Topology" % module.__name__)
-    print("******************************************\n")
-
-    # Shutdown - clean up everything
-    print("*** Killing BGP on Peer routers")
-    # Killing ExaBGP
-    for i in range(1, 9):
-        net["peer%s" % i].cmd("kill `cat /var/run/exabgp/exabgp.pid`")
-
-    # End - Shutdown network
-    net.stop()
 
 
 def test_router_running():
-    global fatal_error
+    tgen = get_topogen()
-    global net
 
-    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
-    if fatal_error != "":
+        pytest.skip(tgen.errors)
-        pytest.skip(fatal_error)
-
-    print("\n\n** Check if FRR is running on each Router node")
-    print("******************************************\n")
-
-    # Starting Routers
-    for i in range(1, 2):
-        fatal_error = net["r%s" % i].checkRouterRunning()
-        assert fatal_error == "", fatal_error
-
-    # For debugging after starting FRR daemons, uncomment the next line
-    # CLI(net)
 
 
 def test_bgp_converge():
     "Check for BGP converged on all peers and BGP views"
 
-    global fatal_error
+    tgen = get_topogen()
-    global net
 
-    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
-    if fatal_error != "":
+        pytest.skip(tgen.errors)
-        pytest.skip(fatal_error)
 
     # Wait for BGP to converge  (All Neighbors in either Full or TwoWay State)
 
@@ -224,7 +169,7 @@ def test_bgp_converge():
         # Look for any node not yet converged
         for i in range(1, 2):
             for view in range(1, 4):
-                notConverged = net["r%s" % i].cmd(
+                notConverged = tgen.net["r%s" % i].cmd(
                     'vtysh -c "show ip bgp view %s summary" 2> /dev/null | grep ^[0-9] | grep -vP " 11\s+(\d+)"'
                     % view
                 )
@@ -242,7 +187,7 @@ def test_bgp_converge():
             break
     else:
         # Bail out with error if a router fails to converge
-        bgpStatus = net["r%s" % i].cmd('vtysh -c "show ip bgp view %s summary"' % view)
+        bgpStatus = tgen.net["r%s" % i].cmd('vtysh -c "show ip bgp view %s summary"' % view)
         assert False, "BGP did not converge:\n%s" % bgpStatus
 
     # Wait for an extra 5s to announce all routes
@@ -256,53 +201,92 @@ def test_bgp_converge():
     #     print("\nwaiting 15s for routes to populate")
     #     sleep(15)
 
-    # Make sure that all daemons are running
+    tgen.routers_have_failure()
-    for i in range(1, 2):
-        fatal_error = net["r%s" % i].checkRouterRunning()
-        assert fatal_error == "", fatal_error
-
-    # For debugging after starting FRR daemons, uncomment the next line
-    # CLI(net)
 
 
 def test_bgp_routingTable():
-    global fatal_error
+    tgen = get_topogen()
-    global net
+
-    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
-    if fatal_error != "":
+        pytest.skip(tgen.errors)
-        pytest.skip(fatal_error)
+
     thisDir = os.path.dirname(os.path.realpath(__file__))
-    print("Verifying BGP Routing Tables")
+
-    def router_json_cmp(router, cmd, data):
+    print("\n\n** Verifying BGP Routing Tables")
-        json_data = json.loads(router.cmd("vtysh -c \"{}\" 2> /dev/null".format(cmd)))
+    print("******************************************\n")
-        return topotest.json_cmp(json_data, data)
+    diffresult = {}
-    router = net["r1"]
-    for view in range(1, 4):
-        json_file = "{}/{}/view_{}.json".format(thisDir, router.name, view)
-        expected = json.loads(open(json_file).read())
-        test_func = partial(
-            router_json_cmp, router, "show ip bgp view {} json".format(view), expected
-        )
-        _, result = topotest.run_and_expect(test_func, None, count=5, wait=1)
-        assertmsg = "Routing Table verification failed for router {}, view {}".format(
-            router.name, view
-        )
-        assert result is None, assertmsg
-    # Make sure that all daemons are running
     for i in range(1, 2):
-        fatal_error = net["r%s" % i].checkRouterRunning()
+        for view in range(1, 4):
-        assert fatal_error == "", fatal_error
+            success = 0
-    # For debugging after starting FRR daemons, uncomment the next line
+            # This glob pattern should work as long as number of views < 10
-    # CLI(net)
+            for refTableFile in glob.glob(
+                "%s/r%s/show_ip_bgp_view_%s*.ref" % (thisDir, i, view)
+            ):
+
+                if os.path.isfile(refTableFile):
+                    # Read expected result from file
+                    expected = open(refTableFile).read().rstrip()
+                    # Fix newlines (make them all the same)
+                    expected = ("\n".join(expected.splitlines()) + "\n").splitlines(1)
+
+                    # Actual output from router
+                    actual = (
+                        tgen.net["r%s" % i]
+                        .cmd('vtysh -c "show ip bgp view %s" 2> /dev/null' % view)
+                        .rstrip()
+                    )
+
+                    # Fix inconsitent spaces between 0.99.24 and newer versions
+                    actual = re.sub("0             0", "0              0", actual)
+                    actual = re.sub(
+                        r"([0-9])         32768", r"\1          32768", actual
+                    )
+                    # Remove summary line (changed recently)
+                    actual = re.sub(r"Total number.*", "", actual)
+                    actual = re.sub(r"Displayed.*", "", actual)
+                    actual = actual.rstrip()
+                    # Fix table version (ignore it)
+                    actual = re.sub(r"(BGP table version is )[0-9]+", r"\1XXX", actual)
+
+                    # Fix newlines (make them all the same)
+                    actual = ("\n".join(actual.splitlines()) + "\n").splitlines(1)
+
+                # Generate Diff
+                diff = topotest.get_textdiff(
+                    actual,
+                    expected,
+                    title1="actual BGP routing table",
+                    title2="expected BGP routing table",
+                )
+
+                if diff:
+                    diffresult[refTableFile] = diff
+                else:
+                    success = 1
+                    print("template %s matched: r%s ok" % (refTableFile, i))
+                    break
+
+            if not success:
+                resultstr = "No template matched.\n"
+                for f in diffresult.keys():
+                    resultstr += (
+                        "template %s: r%s failed Routing Table Check for view %s:\n%s\n"
+                        % (f, i, view, diffresult[f])
+                    )
+                raise AssertionError(
+                    "Routing Table verification failed for router r%s, view %s:\n%s"
+                    % (i, view, resultstr)
+                )
+
+    tgen.routers_have_failure()
 
 
 def test_shutdown_check_stderr():
-    global fatal_error
+    tgen = get_topogen()
-    global net
 
     # Skip if previous fatal error condition is raised
-    if fatal_error != "":
+    if tgen.routers_have_failure():
-        pytest.skip(fatal_error)
+        pytest.skip(tgen.errors)
 
     if os.environ.get("TOPOTESTS_CHECK_STDERR") is None:
         print(
@@ -315,36 +299,22 @@ def test_shutdown_check_stderr():
     print("\n\n** Verifying unexpected STDERR output from daemons")
     print("******************************************\n")
 
-    net["r1"].stopRouter()
+    tgen.net["r1"].stopRouter()
 
-    log = net["r1"].getStdErr("bgpd")
+    log = tgen.net["r1"].getStdErr("bgpd")
     if log:
         print("\nBGPd StdErr Log:\n" + log)
-    log = net["r1"].getStdErr("zebra")
+    log = tgen.net["r1"].getStdErr("zebra")
     if log:
         print("\nZebra StdErr Log:\n" + log)
 
 
 def test_shutdown_check_memleak():
-    global fatal_error
+    tgen = get_topogen()
-    global net
+    if not tgen.is_memleak_enabled():
+        pytest.skip("Memory leak test/report is disabled")
 
-    # Skip if previous fatal error condition is raised
+    tgen.report_memory_leaks()
-    if fatal_error != "":
-        pytest.skip(fatal_error)
-
-    if os.environ.get("TOPOTESTS_CHECK_MEMLEAK") is None:
-        print(
-            "SKIPPED final check on Memory leaks: Disabled (TOPOTESTS_CHECK_MEMLEAK undefined)\n"
-        )
-        pytest.skip("Skipping test for memory leaks")
-
-    thisDir = os.path.dirname(os.path.realpath(__file__))
-
-    net["r1"].stopRouter()
-    net["r1"].report_memory_leaks(
-        os.environ.get("TOPOTESTS_CHECK_MEMLEAK"), os.path.basename(__file__)
-    )
 
 
 if __name__ == "__main__":

tests/topotests/bgp_path_attributes_topo1/test_bgp_path_attributes.py

@@ -94,37 +94,14 @@ from lib.bgp import (
 )
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/bgp_path_attributes.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Address read from env variables
 ADDR_TYPES = check_address_types()
 
 ####
-class CreateTopo(Topo):
-    """
-    Test CreateTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # Building topology and configuration from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -141,7 +118,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_path_attributes.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_peer_group/test_bgp_peer-group.py

@@ -42,10 +42,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -56,7 +53,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_peer_type_multipath_relax/test_bgp_peer-type_multipath-relax.py

@@ -76,10 +76,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-class PeerTypeRelaxTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # Set up routers
     tgen.add_router("r1")  # DUT
@@ -101,7 +99,7 @@ class PeerTypeRelaxTopo(Topo):
 
 def setup_module(mod):
     "Sets up the pytest environment"
-    tgen = Topogen(PeerTypeRelaxTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     # For all registered routers, load the zebra configuration file

tests/topotests/bgp_prefix_list_topo1/test_prefix_lists.py

@@ -73,37 +73,14 @@ from lib.topolog import logger
 from lib.bgp import verify_bgp_convergence, create_router_bgp, clear_bgp_and_verify
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd]
 
 
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/prefix_lists.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Global variables
 bgp_convergence = False
 
 
-class BGPPrefixListTopo(Topo):
-    """
-    Test BGPPrefixListTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        "Build function"
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -118,7 +95,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(BGPPrefixListTopo, mod.__name__)
+    json_file = "{}/prefix_lists.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_prefix_sid/test_bgp_prefix_sid.py

@@ -44,9 +44,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, **_opts):
-        tgen = get_topogen(self)
     router = tgen.add_router("r1")
     switch = tgen.add_switch("s1")
     switch.add_link(router)
@@ -63,7 +61,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(module):
-    tgen = Topogen(TemplateTopo, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     router = tgen.gears["r1"]

tests/topotests/bgp_prefix_sid2/test_bgp_prefix_sid2.py

@@ -44,9 +44,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, **_opts):
-        tgen = get_topogen(self)
     router = tgen.add_router("r1")
     switch = tgen.add_switch("s1")
     switch.add_link(router)
@@ -59,7 +57,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(module):
-    tgen = Topogen(TemplateTopo, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     router = tgen.gears["r1"]

tests/topotests/bgp_recursive_route_ebgp_multi_hop/test_bgp_recursive_route_ebgp_multi_hop.py

@@ -89,14 +89,6 @@ from lib.topojson import build_topo_from_json, build_config_from_json
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
 
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_recursive_route_ebgp_multi_hop.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    logger.info("Could not read file:", jsonFile)
-
 # Global variables
 BGP_CONVERGENCE = False
 KEEP_ALIVE_TIMER = 2
@@ -124,21 +116,6 @@ Loopabck_IP = {
 }
 
 
-class CreateTopo(Topo):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -153,7 +130,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_recursive_route_ebgp_multi_hop.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_reject_as_sets/test_bgp_reject_as_sets.py

@@ -53,10 +53,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -70,7 +67,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_rfapi_basic_sanity/customize.py

@@ -81,12 +81,8 @@ CWD = os.path.dirname(os.path.realpath(__file__))
 TEST = os.path.basename(CWD)
 
 
-class ThisTestTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # This function only purpose is to define allocation and relationship
     # between routers, switches and hosts.

tests/topotests/bgp_rmap_extcommunity_none/test_bgp_rmap_extcommunity_none.py

@@ -41,15 +41,11 @@ sys.path.append(os.path.join(CWD, "../"))
 from lib import topotest
 from lib.topogen import Topogen, TopoRouter, get_topogen
 from lib.topolog import logger
-from mininet.topo import Topo
 
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -59,7 +55,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_route_aggregation/test_bgp_aggregation.py

@@ -70,17 +70,9 @@ from lib.bgp import (
 )
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
-
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_aggregation.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    logger.info("Could not read file:", jsonFile)
-
 # Global variables
 BGP_CONVERGENCE = False
 ADDR_TYPES = check_address_types()
@@ -113,21 +105,6 @@ COMMUNITY = [
 ]
 
 
-class CreateTopo(Topo):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -142,7 +119,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_aggregation.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_route_map/test_route_map_topo1.py

@@ -115,13 +115,6 @@ TC_38:
 bgp_convergence = False
 BGP_CONVERGENCE = False
 ADDR_TYPES = check_address_types()
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_route_map_topo1.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
 
 # Global variables
 bgp_convergence = False
@@ -131,22 +124,6 @@ NEXT_HOP = {"ipv4": "10.0.0.2", "ipv6": "fd00::2"}
 ADDR_TYPES = check_address_types()
 
 
-class CreateTopo(Topo):
-    """
-    Test topology builder
-
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -161,7 +138,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_route_map_topo1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_route_map/test_route_map_topo2.py

@@ -147,18 +147,9 @@ from lib.bgp import (
 )
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
-
-# Reading the data from JSON File for topology and configuration creation
-jsonFile = "{}/bgp_route_map_topo2.json".format(CWD)
-
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Global variables
 # Global variables
 bgp_convergence = False
@@ -169,21 +160,6 @@ BGP_CONVERGENCE = False
 ADDR_TYPES = check_address_types()
 
 
-class BGPRmapTopo(Topo):
-    """BGPRmapTopo.
-
-    BGPRmap topology 1
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function."""
-        tgen = get_topogen(self)
-
-        # Building topology and configuration from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """setup_module.
 
@@ -197,7 +173,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(BGPRmapTopo, mod.__name__)
+    json_file = "{}/bgp_route_map_topo2.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_rr_ibgp/test_bgp_rr_ibgp_topo1.py

@@ -49,24 +49,13 @@ from lib.topolog import logger
 # Required to instantiate the topology builder class.
 from lib.micronet_compat import Topo
 
+
 pytestmark = [pytest.mark.bgpd]
 
 
-#####################################################
+def build_topo(tgen):
-##
-##   Network Topology Definition
-##
-#####################################################
-
-
-class NetworkTopo(Topo):
-    "BGP_RR_IBGP Topology 1"
-
-    def build(self, **_opts):
     "Build function"
 
-        tgen = get_topogen(self)
-
     tgen.add_router("tor1")
     tgen.add_router("tor2")
     tgen.add_router("spine1")
@@ -102,7 +91,7 @@ class NetworkTopo(Topo):
 
 def setup_module(module):
     "Setup topology"
-    tgen = Topogen(NetworkTopo, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     # This is a sample of configuration loading.

tests/topotests/bgp_sender_as_path_loop_detection/test_bgp_sender-as-path-loop-detection.py

@@ -47,10 +47,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -64,7 +61,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_set_local_preference_add_subtract/test_bgp_set_local-preference_add_subtract.py

@@ -47,10 +47,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -61,7 +58,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_snmp_mplsl3vpn/test_bgp_snmp_mplsvpn.py

@@ -50,12 +50,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd, pytest.mark.isisd, pytest.mark.snmp]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # This function only purpose is to define allocation and relationship
     # between routers, switches and hosts.
@@ -131,7 +127,7 @@ def setup_module(mod):
         pytest.skip(error_msg)
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
     tgen.start_topology()
 

tests/topotests/bgp_srv6l3vpn_to_bgp_vrf/test_bgp_srv6l3vpn_to_bgp_vrf.py

@@ -42,7 +42,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class Topology(Topo):
+def build_topo(tgen):
     """
       CE1     CE3      CE5
     (eth0)  (eth0)   (eth0)
@@ -79,8 +79,6 @@ class Topology(Topo):
       (eth0)      (eth0)      (eth0)
         CE2         CE4         CE6
     """
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
     tgen.add_router("r1")
     tgen.add_router("r2")
     tgen.add_router("ce1")
@@ -104,7 +102,7 @@ def setup_module(mod):
     if result is not True:
         pytest.skip("Kernel requirements are not met")
 
-    tgen = Topogen(Topology, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
     router_list = tgen.routers()
     for rname, router in tgen.routers().items():

tests/topotests/bgp_suppress_fib/test_bgp_suppress_fib.py

@@ -43,10 +43,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -60,7 +57,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_tcp_mss/test_bgp_tcp_mss.py

@@ -54,10 +54,7 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
-
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
 
@@ -67,7 +64,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_update_delay/test_bgp_update_delay.py

@@ -76,10 +76,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class TemplateTopo(Topo):
+CWD = os.path.dirname(os.path.realpath(__file__))
-    def build(self, *_args, **_opts):
+def build_topo(tgen):
-        tgen = get_topogen(self)
-
     for routern in range(1, 6):
         tgen.add_router("r{}".format(routern))
 
@@ -101,7 +99,7 @@ class TemplateTopo(Topo):
 
 
 def setup_module(mod):
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_vrf_dynamic_route_leak/test_bgp_vrf_dynamic_route_leak_topo1.py

@@ -81,17 +81,9 @@ from lib.bgp import (
 )
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
-
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/bgp_vrf_dynamic_route_leak_topo1.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Global variables
 NETWORK1_1 = {"ipv4": "11.11.11.1/32", "ipv6": "11:11::1/128"}
 NETWORK1_2 = {"ipv4": "11.11.11.11/32", "ipv6": "11:11::11/128"}
@@ -125,21 +117,6 @@ LOOPBACK_2 = {
 PREFERRED_NEXT_HOP = "global"
 
 
-class CreateTopo(Topo):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -147,7 +124,6 @@ def setup_module(mod):
     * `mod`: module name
     """
 
-    global topo
     testsuite_run_time = time.asctime(time.localtime(time.time()))
     logger.info("Testsuite start time: {}".format(testsuite_run_time))
     logger.info("=" * 40)
@@ -155,7 +131,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/bgp_vrf_dynamic_route_leak_topo1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_vrf_dynamic_route_leak/test_bgp_vrf_dynamic_route_leak_topo2.py

@@ -97,16 +97,8 @@ NETWORK3_4 = {"ipv4": "50.50.50.50/32", "ipv6": "50:50::50/128"}
 PREFERRED_NEXT_HOP = "global"
 
 
-class CreateTopo(Topo):
+def build_topo(tgen):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
     """Build function"""
-        tgen = get_topogen(self)
 
     # Building topology from json file
     build_topo_from_json(tgen, topo)
@@ -127,7 +119,7 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/bgp_vrf_lite_ipv6_rtadv/test_bgp_vrf_lite_ipv6_rtadv.py

@@ -50,12 +50,8 @@ from lib.micronet_compat import Topo
 pytestmark = [pytest.mark.bgpd]
 
 
-class BGPIPV6RTADVVRFTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     # Create 2 routers.
     tgen.add_router("r1")
@@ -74,7 +70,7 @@ def setup_module(mod):
     if result is not True:
         pytest.skip("Kernel requirements are not met")
 
-    tgen = Topogen(BGPIPV6RTADVVRFTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/bgp_vrf_netns/test_bgp_vrf_netns_topo.py

@@ -57,13 +57,7 @@ CustomizeVrfWithNetns = True
 #####################################################
 
 
-class BGPVRFNETNSTopo1(Topo):
+def build_topo(tgen):
-    "BGP EBGP VRF NETNS Topology 1"
-
-    def build(self, **_opts):
-        tgen = get_topogen(self)
-
-        # Setup Routers
     tgen.add_router("r1")
 
     # Setup Switches
@@ -86,7 +80,7 @@ class BGPVRFNETNSTopo1(Topo):
 
 
 def setup_module(module):
-    tgen = Topogen(BGPVRFNETNSTopo1, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     # Get r1 reference

tests/topotests/bgp_vrf_route_leak_basic/test_bgp-vrf-route-leak-basic.py

@@ -41,13 +41,12 @@ from lib.topolog import logger
 
 from lib.micronet_compat import Topo
 
+
 pytestmark = [pytest.mark.bgpd]
 
 
-class BGPVRFTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
     for routern in range(1, 2):
         tgen.add_router("r{}".format(routern))
@@ -55,7 +54,7 @@ class BGPVRFTopo(Topo):
 
 def setup_module(mod):
     "Sets up the pytest environment"
-    tgen = Topogen(BGPVRFTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     # For all registered routers, load the zebra configuration file

tests/topotests/config_timing/test_config_timing.py

@@ -49,16 +49,14 @@ from lib.micronet_compat import Topo
 
 pytestmark = [pytest.mark.staticd]
 
-class TimingTopo(Topo):
+def build_topo(tgen):
-    def build(self, *_args, **_opts):
-        tgen = get_topogen(self)
     tgen.add_router("r1")
     switch = tgen.add_switch("s1")
     switch.add_link(tgen.gears["r1"])
 
 
 def setup_module(mod):
-    tgen = Topogen(TimingTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     tgen.start_topology()
 
     router_list = tgen.routers()

tests/topotests/eigrp_topo1/test_eigrp_topo1.py

@@ -55,14 +55,7 @@ from lib.micronet_compat import Topo
 #####################################################
 
 
-class NetworkTopo(Topo):
+def build_topo(tgen):
-    "EIGRP Topology 1"
-
-    def build(self, **_opts):
-        "Build function"
-
-        tgen = get_topogen(self)
-
     for routern in range(1, 4):
         tgen.add_router("r{}".format(routern))
 
@@ -96,7 +89,7 @@ class NetworkTopo(Topo):
 
 def setup_module(module):
     "Setup topology"
-    tgen = Topogen(NetworkTopo, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     # This is a sample of configuration loading.

tests/topotests/evpn_pim_1/test_evpn_pim_topo1.py

@@ -59,14 +59,7 @@ pytestmark = [pytest.mark.bgpd, pytest.mark.bgpd]
 #####################################################
 
 
-class NetworkTopo(Topo):
+def build_topo(tgen):
-    "evpn-pim Topology 1"
-
-    def build(self, **_opts):
-        "Build function"
-
-        tgen = get_topogen(self)
-
     tgen.add_router("spine")
     tgen.add_router("leaf1")
     tgen.add_router("leaf2")
@@ -105,7 +98,7 @@ class NetworkTopo(Topo):
 
 def setup_module(module):
     "Setup topology"
-    tgen = Topogen(NetworkTopo, module.__name__)
+    tgen = Topogen(build_topo, module.__name__)
     tgen.start_topology()
 
     leaf1 = tgen.gears["leaf1"]

tests/topotests/evpn_type5_test_topo1/test_evpn_type5_chaos_topo1.py

@@ -85,17 +85,9 @@ from lib.bgp import (
 )
 from lib.topojson import build_topo_from_json, build_config_from_json
 
+
 pytestmark = [pytest.mark.bgpd, pytest.mark.staticd]
 
-
-# Reading the data from JSON File for topology creation
-jsonFile = "{}/evpn_type5_chaos_topo1.json".format(CWD)
-try:
-    with open(jsonFile, "r") as topoJson:
-        topo = json.load(topoJson)
-except IOError:
-    assert False, "Could not read file {}".format(jsonFile)
-
 # Reading the data from JSON File for topology creation
 # Global variables
 TCPDUMP_FILE = "evpn_log.txt"
@@ -139,21 +131,6 @@ BRCTL = {
 }
 
 
-class CreateTopo(Topo):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
-        build_topo_from_json(tgen, topo)
-
-
 def setup_module(mod):
     """
     Sets up the pytest environment
@@ -161,7 +138,6 @@ def setup_module(mod):
     * `mod`: module name
     """
 
-    global topo
     testsuite_run_time = time.asctime(time.localtime(time.time()))
     logger.info("Testsuite start time: {}".format(testsuite_run_time))
     logger.info("=" * 40)
@@ -169,7 +145,10 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    json_file = "{}/evpn_type5_chaos_topo1.json".format(CWD)
+    tgen = Topogen(json_file, mod.__name__)
+    global topo
+    topo = tgen.json_topo
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/evpn_type5_test_topo1/test_evpn_type5_topo1.py

@@ -142,18 +142,7 @@ BRCTL = {
 }
 
 
-class CreateTopo(Topo):
+def build_topo(tgen):
-    """
-    Test BasicTopo - topology 1
-
-    * `Topo`: Topology object
-    """
-
-    def build(self, *_args, **_opts):
-        """Build function"""
-        tgen = get_topogen(self)
-
-        # Building topology from json file
     build_topo_from_json(tgen, topo)
 
 
@@ -172,7 +161,7 @@ def setup_module(mod):
     logger.info("Running setup_module to create topology")
 
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(CreateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
     # ... and here it calls Mininet initialization functions.
 
     # Starting topology, create tmp files which are loaded to routers

tests/topotests/example_test/test_template.py

@@ -30,19 +30,10 @@ import os
 import sys
 import pytest
 
-# Save the Current Working Directory to find configuration files.
-CWD = os.path.dirname(os.path.realpath(__file__))
-sys.path.append(os.path.join(CWD, "../"))
-
-# pylint: disable=C0413
 # Import topogen and topotest helpers
-from lib import topotest
 from lib.topogen import Topogen, TopoRouter, get_topogen
 from lib.topolog import logger
 
-# Required to instantiate the topology builder class.
-from lib.micronet_compat import Topo
-
 
 # TODO: select markers based on daemons used during test
 # pytest module level markers
@@ -56,18 +47,9 @@ pytestmark = [
 """
 
 
-class TemplateTopo(Topo):
+def build_topo(tgen):
-    "Test topology builder"
-
-    def build(self, *_args, **_opts):
     "Build function"
-        tgen = get_topogen(self)
 
-        # This function only purpose is to define allocation and relationship
-        # between routers, switches and hosts.
-        #
-        # Example
-        #
     # Create 2 routers
     for routern in range(1, 3):
         tgen.add_router("r{}".format(routern))
@@ -85,8 +67,20 @@ class TemplateTopo(Topo):
 
 def setup_module(mod):
     "Sets up the pytest environment"
+
+
     # This function initiates the topology build with Topogen...
-    tgen = Topogen(TemplateTopo, mod.__name__)
+    tgen = Topogen(build_topo, mod.__name__)
+
+    # The basic topology above could also have be more easily specified using a
+    # dictionary, remove the build_topo function and use the following instead:
+    #
+    # topodef = {
+    #     "s1": "r1"
+    #     "s2": ("r1", "r2")
+    # }
+    # tgen = Topogen(topodef, mod.__name__)
+
     # ... and here it calls initialization functions.
     tgen.start_topology()
 
@@ -94,6 +88,7 @@ def setup_module(mod):
     router_list = tgen.routers()
 
     # For all registred routers, load the zebra configuration file
+    # CWD = os.path.dirname(os.path.realpath(__file__))
     for rname, router in router_list.items():
         router.load_config(
             TopoRouter.RD_ZEBRA,