Merge pull request #6469 from mjstapp/add_ubu_20_doc

doc: add dev doc for ubuntu 20.04

doc/developer/building-frr-for-ubuntu2004.rst

@@ -0,0 +1,162 @@
+Ubuntu 20.04 LTS
+================
+
+This document describes installation from source. If you want to build a
+``deb``, see :ref:`packaging-debian`.
+
+Installing Dependencies
+-----------------------
+
+.. code-block:: console
+
+   sudo apt update
+   sudo apt-get install \
+      git autoconf automake libtool make libreadline-dev texinfo \
+      pkg-config libpam0g-dev libjson-c-dev bison flex python3-pytest \
+      libc-ares-dev python3-dev libsystemd-dev python-ipaddress python3-sphinx \
+      install-info build-essential libsystemd-dev libsnmp-dev perl \
+      libcap-dev python2
+
+Note that Ubuntu 20 no longer installs python 2.x, so it must be
+installed explicitly. Ensure that your system has a symlink named
+``/usr/bin/python`` pointing at ``/usr/bin/python3``.
+
+In addition, ``pip`` for python2 must be installed if you wish to run
+the FRR topotests. That version of ``pip`` is not available from the
+ubuntu apt repositories; in order to install it:
+
+.. code-block:: shell
+
+   curl https://bootstrap.pypa.io/get-pip.py --output get-pip.py
+   sudo ./get-pip.py
+
+   # And verify the installation
+   pip2 --version
+
+.. include:: building-libyang.rst
+
+Protobuf
+^^^^^^^^
+
+.. code-block:: console
+
+   sudo apt-get install protobuf-c-compiler libprotobuf-c-dev
+
+ZeroMQ
+^^^^^^
+
+.. code-block:: console
+
+   sudo apt-get install libzmq5 libzmq3-dev
+
+Building & Installing FRR
+-------------------------
+
+Add FRR user and groups
+^^^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: console
+
+   sudo groupadd -r -g 92 frr
+   sudo groupadd -r -g 85 frrvty
+   sudo adduser --system --ingroup frr --home /var/run/frr/ \
+      --gecos "FRR suite" --shell /sbin/nologin frr
+   sudo usermod -a -G frrvty frr
+
+Compile
+^^^^^^^
+
+.. include:: include-compile.rst
+
+Install FRR configuration files
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: console
+
+   sudo install -m 775 -o frr -g frr -d /var/log/frr
+   sudo install -m 775 -o frr -g frrvty -d /etc/frr
+   sudo install -m 640 -o frr -g frrvty tools/etc/frr/vtysh.conf /etc/frr/vtysh.conf
+   sudo install -m 640 -o frr -g frr tools/etc/frr/frr.conf /etc/frr/frr.conf
+   sudo install -m 640 -o frr -g frr tools/etc/frr/daemons.conf /etc/frr/daemons.conf
+   sudo install -m 640 -o frr -g frr tools/etc/frr/daemons /etc/frr/daemons
+
+Tweak sysctls
+^^^^^^^^^^^^^
+
+Some sysctls need to be changed in order to enable IPv4/IPv6 forwarding and
+MPLS (if supported by your platform). If your platform does not support MPLS,
+skip the MPLS related configuration in this section.
+
+Edit :file:`/etc/sysctl.conf` and uncomment the following values (ignore the
+other settings):
+
+::
+
+   # Uncomment the next line to enable packet forwarding for IPv4
+   net.ipv4.ip_forward=1
+
+   # Uncomment the next line to enable packet forwarding for IPv6
+   #  Enabling this option disables Stateless Address Autoconfiguration
+   #  based on Router Advertisements for this host
+   net.ipv6.conf.all.forwarding=1
+
+Reboot or use ``sysctl -p`` to apply the same config to the running system.
+
+Add MPLS kernel modules
+"""""""""""""""""""""""
+
+Ubuntu 20.04 ships with kernel 5.4; MPLS modules are present by default.  To
+enable, add the following lines to :file:`/etc/modules-load.d/modules.conf`:
+
+::
+
+   # Load MPLS Kernel Modules
+   mpls_router
+   mpls_iptunnel
+
+
+And load the kernel modules on the running system:
+
+.. code-block:: console
+
+   sudo modprobe mpls-router mpls-iptunnel
+
+If the above command returns an error, you may need to install the appropriate
+or latest linux-modules-extra-<kernel-version>-generic package. For example
+``apt-get install linux-modules-extra-`uname -r`-generic``
+
+Enable MPLS Forwarding
+""""""""""""""""""""""
+
+Edit :file:`/etc/sysctl.conf` and the following lines. Make sure to add a line
+equal to :file:`net.mpls.conf.eth0.input` for each interface used with MPLS.
+
+::
+
+   # Enable MPLS Label processing on all interfaces
+   net.mpls.conf.eth0.input=1
+   net.mpls.conf.eth1.input=1
+   net.mpls.conf.eth2.input=1
+   net.mpls.platform_labels=100000
+
+Install service files
+^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: console
+
+   sudo install -m 644 tools/frr.service /etc/systemd/system/frr.service
+   sudo systemctl enable frr
+
+Enable daemons
+^^^^^^^^^^^^^^
+
+Open :file:`/etc/frr/daemons` with your text editor of choice. Look for the
+section with ``watchfrr_enable=...`` and ``zebra=...`` etc.  Enable the daemons
+as required by changing the value to ``yes``.
+
+Start FRR
+^^^^^^^^^
+
+.. code-block:: shell
+
+   systemctl start frr

doc/developer/building.rst

@@ -26,4 +26,5 @@ Building FRR
    building-frr-for-ubuntu1404
    building-frr-for-ubuntu1604
    building-frr-for-ubuntu1804
+   building-frr-for-ubuntu2004
    building-frr-for-archlinux

doc/developer/subdir.am

@@ -22,6 +22,7 @@ dev_RSTFILES = \
 	doc/developer/building-frr-for-ubuntu1404.rst \
 	doc/developer/building-frr-for-ubuntu1604.rst \
 	doc/developer/building-frr-for-ubuntu1804.rst \
+	doc/developer/building-frr-for-ubuntu2004.rst \
 	doc/developer/building-libyang.rst \
 	doc/developer/building.rst \
 	doc/developer/cli.rst \