proxmox-mirrors/mirror_lxc
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_lxc synced 2025-08-03 13:28:12 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

add a start-host hook (v2)

Browse Source 
This should satisfy several use cases.  The one I tested for was CNI.
I replaced the network configuration in a root owned container with:

lxc.net.0.type = empty
lxc.hook.start-host = /bin/lxc-start-netns

where /bin/lxc-start-netns contained:

=================================

echo "starting" > /tmp/debug
ip link add host1 type veth peer name peer1
ip link set host1 master lxcbr0
ip link set host1 up
ip link set peer1 netns "${LXC_PID}"
=================================

The nic 'peer1' was placed into the container as expected.

For this to work, we pass the container init's pid as LXC_PID in
an environment variable, since lxc-info cannot work at that point.

Signed-off-by: Serge Hallyn <shallyn@cisco.com>
This commit is contained in:
Serge Hallyn 2017-09-20 21:22:46 +00:00
parent 08dc351a36
commit 08dd280543
6 changed files with 37 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
doc/lxc.container.conf.sgml.in
View File

@ -1519,6 +1519,20 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
</listitem>
</varlistentry>
</variablelist>
<variablelist>
<varlistentry>
<term>
<option>lxc.hook.start-host</option>
</term>
<listitem>
<para>
A hook to be run in the host's namespace after the
container has been setup, and immediately before starting
the container init.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist>
<varlistentry>
<term>

5
src/lxc/conf.c
View File

@ -236,7 +236,8 @@ extern int memfd_create(const char *name, unsigned int flags);
char *lxchook_names[NUM_LXC_HOOKS] = {"pre-start", "pre-mount", "mount",
"autodev", "start", "stop",
"post-stop", "clone", "destroy"};
"post-stop", "clone", "destroy",
"start-host"};
struct mount_opt {
char *name;
@ -3285,6 +3286,8 @@ int run_lxc_hooks(const char *name, char *hook, struct lxc_conf *conf,
if (strcmp(hook, "pre-start") == 0)
which = LXCHOOK_PRESTART;
else if (strcmp(hook, "start-host") == 0)
which = LXCHOOK_START_HOST;
else if (strcmp(hook, "pre-mount") == 0)
which = LXCHOOK_PREMOUNT;
else if (strcmp(hook, "mount") == 0)

1
src/lxc/conf.h
View File

@ -228,6 +228,7 @@ enum lxchooks {
LXCHOOK_POSTSTOP,
LXCHOOK_CLONE,
LXCHOOK_DESTROY,
LXCHOOK_START_HOST,
NUM_LXC_HOOKS
};

4
src/lxc/confile.c
View File

@ -155,6 +155,7 @@ static struct lxc_config_t config[] = {
{ "lxc.hook.destroy", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.mount", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.post-stop", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.start-host", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.pre-start", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.pre-mount", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
{ "lxc.hook.start", false, set_config_hooks, get_config_hooks, clr_config_hooks, },
@ -980,6 +981,8 @@ static int set_config_hooks(const char *key, const char *value,
if (strcmp(key + 9, "pre-start") == 0)
return add_hook(lxc_conf, LXCHOOK_PRESTART, copy);
else if (strcmp(key + 9, "start-host") == 0)
return add_hook(lxc_conf, LXCHOOK_START_HOST, copy);
else if (strcmp(key + 9, "pre-mount") == 0)
return add_hook(lxc_conf, LXCHOOK_PREMOUNT, copy);
else if (strcmp(key + 9, "autodev") == 0)
@ -4445,6 +4448,7 @@ int lxc_list_subkeys(struct lxc_conf *conf, const char *key, char *retv,
strprint(retv, inlen, "post-stop\n");
strprint(retv, inlen, "pre-mount\n");
strprint(retv, inlen, "pre-start\n");
strprint(retv, inlen, "start-host\n");
strprint(retv, inlen, "start\n");
strprint(retv, inlen, "stop\n");
} else if (!strcmp(key, "lxc.cap")) {

15
src/lxc/start.c
View File

@ -1165,6 +1165,7 @@ static int lxc_spawn(struct lxc_handler *handler)
{
int i, flags, ret;
const char *name = handler->name;
char pidstr[20];
bool wants_to_map_ids;
int saved_ns_fd[LXC_NS_MAX];
struct lxc_list *id_map;
@ -1355,13 +1356,23 @@ static int lxc_spawn(struct lxc_handler *handler)
cgroup_disconnect();
cgroups_connected = false;
snprintf(pidstr, 20, "%d", handler->pid);
if (setenv("LXC_PID", pidstr, 1))
SYSERROR("Failed to set environment variable: LXC_PID=%s.", pidstr);
/* Run any host-side start hooks */
if (run_lxc_hooks(name, "start-host", handler->conf, handler->lxcpath, NULL)) {
ERROR("Failed to run lxc.hook.start-host for container \"%s\".", name);
return -1;
}
/* Tell the child to complete its initialization and wait for it to exec
* or return an error. (The child will never return
* LXC_SYNC_POST_CGROUP+1. It will either close the sync pipe, causing
* LXC_SYNC_READY_START+1. It will either close the sync pipe, causing
* lxc_sync_barrier_child to return success, or return a different
* value, causing us to error out).
*/
if (lxc_sync_barrier_child(handler, LXC_SYNC_POST_CGROUP))
if (lxc_sync_barrier_child(handler, LXC_SYNC_READY_START))
return -1;
if (lxc_network_recv_name_and_ifindex_from_child(handler) < 0) {

2
src/lxc/sync.h
View File

@ -32,7 +32,7 @@ enum {
LXC_SYNC_CGROUP,
LXC_SYNC_CGROUP_UNSHARE,
LXC_SYNC_CGROUP_LIMITS,
LXC_SYNC_POST_CGROUP,
LXC_SYNC_READY_START,
LXC_SYNC_RESTART,
LXC_SYNC_POST_RESTART,
LXC_SYNC_ERROR = -1 /* Used to report errors from another process */