ifconfig: T2985: support on demand bridge creation

The current implementation for bridge based interfaces has an issue which is
caused by priority inheritance. We always assumed that the bridge interface will
be created last, but this may not be true in all cases, where some interfaces
will be created "on demand" - e.g. OpenVPN or late (VXLAN, GENEVE).

As we already have a bunch of verify steps in place we should not see a bridge
interface leak to the underlaying infrastructure code. This means, whenever an
interface will be member of a bridge, and the bridge does yet not exist, we will
create it in advance in the interface context, as the bridge code will be run
in the same commit but maybe sooner or later.

This will also be the solution for T2924.

1 files changed, 7 insertions, 15 deletions

diff --git a/python/vyos/configdict.py b/python/vyos/configdict.py
index 02006465c..62df3334c 100644
--- a/python/vyos/configdict.py
+++ b/python/vyos/configdict.py
@@ -194,11 +194,9 @@ def is_member(conf, interface, intftype=None):
     interface name -> Interface is a member of this interface
     False -> interface type cannot have members
     """
-    from vyos.xml import is_tag
-    from vyos.xml import is_leaf
-
     ret_val = None
     intftypes = ['bonding', 'bridge']
+
     if intftype not in intftypes + [None]:
         raise ValueError((
             f'unknown interface type "{intftype}" or it cannot '
@@ -210,19 +208,13 @@ def is_member(conf, interface, intftype=None):
     old_level = conf.get_level()
     conf.set_level([])
 
-    for it in intftype:
-        base = ['interfaces', it]
+    for iftype in intftype:
+        base = ['interfaces', iftype]
         for intf in conf.list_nodes(base):
-            memberintf = base + [intf, 'member', 'interface']
-            if is_tag(memberintf):
-                if interface in conf.list_nodes(memberintf):
-                    ret_val = intf
-                    break
-            elif is_leaf(memberintf):
-                if ( conf.exists(memberintf) and
-                        interface in conf.return_values(memberintf) ):
-                    ret_val = intf
-                    break
+            member = base + [intf, 'member', 'interface', interface]
+            if conf.exists(member):
+                tmp = conf.get_config_dict(member, key_mangling=('-', '_'), get_first_key=True)
+                ret_val = {intf : tmp}
 
     old_level = conf.set_level(old_level)
     return ret_val