Add /run/netns bindmount to Neutron containers

Closes-Bug: #1864856
Change-Id: I725eeb18a22b3fa7838f16761d19f7e699ab5e82
(cherry picked from commit 61a59e015f)
(cherry picked from commit 9f9e1efa8c)

ansible/roles/neutron/defaults/main.yml

@@ -103,6 +103,7 @@ neutron_services:
       - "{{ node_config_directory }}/neutron-dhcp-agent/:{{ container_config_directory }}/:ro"
       - "/etc/localtime:/etc/localtime:ro"
       - "neutron_metadata_socket:/var/lib/neutron/kolla/"
+      - "/run/netns:/run/netns:shared"
       - "kolla_logs:/var/log/kolla/"
     dimensions: "{{ neutron_dhcp_agent_dimensions }}"
   neutron-l3-agent:
@@ -120,6 +121,7 @@ neutron_services:
       - "/etc/localtime:/etc/localtime:ro"
       - "/lib/modules:/lib/modules:ro"
       - "neutron_metadata_socket:/var/lib/neutron/kolla/"
+      - "/run/netns:/run/netns:shared"
       - "kolla_logs:/var/log/kolla/"
     dimensions: "{{ neutron_l3_agent_dimensions }}"
   neutron-lbaas-agent:

releasenotes/notes/bug-1861792-a44a31693b0c786f.yaml

@@ -2,4 +2,5 @@
 fixes:
   - |
     Remove /run bind mounts in Neutron services causing dbus host-level
-    errors `LP# 1861792 <https://launchpad.net/bugs/1861792>`.
+    errors and add /run/netns for neutron-dhcp-agent and neutron-l3-agent.
+    `LP# 1861792 <https://launchpad.net/bugs/1861792>`__