fix(get_config): strip veth interfaces — Docker container churn causes false-positive config changes every poll

Docker creates a fresh veth pair with a new random name and ifindex
for every container start/restart. ip addr show includes them, so
get_config() reported a "config change" on nearly every poll of a
Docker host even though nothing about the host's own configuration
changed.

napalm_linux/linux.py

@@ -697,13 +697,19 @@ class LinuxDriver(OSDriver):
 
         ``valid_lft`` / ``preferred_lft`` fields from DHCP leases are stripped
         so the output is stable across polls and does not produce false-positive
-        config-change events in the config-backup feature.
+        config-change events in the config-backup feature. ``veth*`` interfaces
+        are stripped entirely — Docker creates/destroys them with a fresh index
+        and random name on every container restart, which would otherwise flag
+        a config change on nearly every poll of a Docker host.
         """
         import re
 
         running = self._send("ip addr show && ip route show")
         # Strip volatile DHCP lease timer fields — they decrement every poll
         running = re.sub(r"\s+valid_lft\s+\S+\s+preferred_lft\s+\S+", "", running)
+        # Strip veth interface blocks (line + indented sub-lines) — ephemeral
+        # Docker container network endpoints, not intentional host config
+        running = re.sub(r"^\d+: veth\S*:.*\n(?:[ \t]+.*\n?)*", "", running, flags=re.MULTILINE)
         return {"running": running, "startup": "", "candidate": ""}
 
     # ------------------------------------------------------------------