From 5bb772cf50ad4d851c564aeb50b10ed64ef38ee0 Mon Sep 17 00:00:00 2001
From: Pete Birley <pete@port.direct>
Date: Thu, 19 Apr 2018 22:34:20 -0500
Subject: [PATCH] Neutron: Enable sharing of network namespaces with host

This PS enables sharing of network namespaces with the host,
allowing for hitless upgrades of agents, and much simpler debugging.

It does however require mount propogation to be enabled in kubernetes
which is a alpha gated feature introduced in 1.8, and enabled by default
as a beta feature in 1.10.

Depends-On: I7a37f45ff6061b144c6f04233712cd84fccb3e83
Change-Id: I2a191a343fe637cbfd9e4af5277f9784af736dd1
---
 neutron/templates/daemonset-dhcp-agent.yaml     | 10 ++++++++++
 neutron/templates/daemonset-l3-agent.yaml       | 10 ++++++++++
 neutron/templates/daemonset-metadata-agent.yaml | 10 ++++++++++
 neutron/values.yaml                             |  4 ++++
 4 files changed, 34 insertions(+)

diff --git a/neutron/templates/daemonset-dhcp-agent.yaml b/neutron/templates/daemonset-dhcp-agent.yaml
index ab98e341..5cba9f0e 100644
--- a/neutron/templates/daemonset-dhcp-agent.yaml
+++ b/neutron/templates/daemonset-dhcp-agent.yaml
@@ -113,6 +113,11 @@ spec:
             {{- end }}
             - name: socket
               mountPath: /var/lib/neutron/openstack-helm
+            {{- if .Values.network.share_namespaces }}
+            - name: host-run-netns
+              mountPath: /run/netns
+              mountPropagation: Bidirectional
+            {{- end }}
 {{ if $mounts_neutron_dhcp_agent.volumeMounts }}{{ toYaml $mounts_neutron_dhcp_agent.volumeMounts | indent 12 }}{{ end }}
       volumes:
         - name: neutron-bin
@@ -131,6 +136,11 @@ spec:
         - name: socket
           hostPath:
             path: /var/lib/neutron/openstack-helm
+        {{- if .Values.network.share_namespaces }}
+        - name: host-run-netns
+          hostPath:
+            path: /run/netns
+        {{- end }}
 {{ if $mounts_neutron_dhcp_agent.volumes }}{{ toYaml $mounts_neutron_dhcp_agent.volumes | indent 8 }}{{ end }}
 {{- end }}
 {{- end }}
diff --git a/neutron/templates/daemonset-l3-agent.yaml b/neutron/templates/daemonset-l3-agent.yaml
index bacbe04c..e05e0be5 100644
--- a/neutron/templates/daemonset-l3-agent.yaml
+++ b/neutron/templates/daemonset-l3-agent.yaml
@@ -112,6 +112,11 @@ spec:
               readOnly: true
             - name: socket
               mountPath: /var/lib/neutron/openstack-helm
+            {{- if .Values.network.share_namespaces }}
+            - name: host-run-netns
+              mountPath: /run/netns
+              mountPropagation: Bidirectional
+            {{- end }}
 {{ if $mounts_neutron_l3_agent.volumeMounts }}{{ toYaml $mounts_neutron_l3_agent.volumeMounts | indent 12 }}{{ end }}
       volumes:
         - name: neutron-bin
@@ -133,6 +138,11 @@ spec:
         - name: socket
           hostPath:
             path: /var/lib/neutron/openstack-helm
+        {{- if .Values.network.share_namespaces }}
+        - name: host-run-netns
+          hostPath:
+            path: /run/netns
+        {{- end }}
 {{ if $mounts_neutron_l3_agent.volumes }}{{ toYaml $mounts_neutron_l3_agent.volumes | indent 8 }}{{ end }}
 {{- end }}
 {{- end }}
diff --git a/neutron/templates/daemonset-metadata-agent.yaml b/neutron/templates/daemonset-metadata-agent.yaml
index 32dc87ac..1dc92a2d 100644
--- a/neutron/templates/daemonset-metadata-agent.yaml
+++ b/neutron/templates/daemonset-metadata-agent.yaml
@@ -127,6 +127,11 @@ spec:
             {{- end }}
             - name: socket
               mountPath: /var/lib/neutron/openstack-helm
+            {{- if .Values.network.share_namespaces }}
+            - name: host-run-netns
+              mountPath: /run/netns
+              mountPropagation: Bidirectional
+            {{- end }}
 {{ if $mounts_neutron_metadata_agent.volumeMounts }}{{ toYaml $mounts_neutron_metadata_agent.volumeMounts | indent 12 }}{{ end }}
       volumes:
         - name: neutron-bin
@@ -145,6 +150,11 @@ spec:
         - name: socket
           hostPath:
             path: /var/lib/neutron/openstack-helm
+        {{- if .Values.network.share_namespaces }}
+        - name: host-run-netns
+          hostPath:
+            path: /run/netns
+        {{- end }}
 {{ if $mounts_neutron_metadata_agent.volumes }}{{ toYaml $mounts_neutron_metadata_agent.volumes | indent 8 }}{{ end }}
 {{- end }}
 {{- end }}
diff --git a/neutron/values.yaml b/neutron/values.yaml
index a32bcda1..61d82387 100644
--- a/neutron/values.yaml
+++ b/neutron/values.yaml
@@ -80,6 +80,10 @@ network:
   # possible options: openvswitch, linuxbridge, sriov
   backend:
     - openvswitch
+  # NOTE(Portdirect): Share network namespaces with the host,
+  # allowing agents to be restarted without packet loss and simpler
+  # debugging. This feature requires mount propagation support.
+  share_namespaces: true
   external_bridge: br-ex
   ip_address: 0.0.0.0
   interface: