Install plugins in neutron-server if available

Implements: blueprint neutron-third-party-plugins

Change-Id: I56c56bacd2f06c120b14b00c0b97dd4e39c0afc0

docker/neutron/neutron-server/Dockerfile.j2

@@ -1,7 +1,11 @@
 FROM {{ namespace }}/{{ image_prefix }}neutron-base:{{ tag }}
 MAINTAINER {{ maintainer }}
 
+ADD plugins-archive /
 COPY extend_start.sh /usr/local/bin/kolla_extend_start
-RUN chmod 755 /usr/local/bin/kolla_extend_start
+RUN chmod 755 /usr/local/bin/kolla_extend_start \
+    && if [[ "$(ls /plugins)" ]]; then \
+           pip --no-cache-dir install -c requirements/upper-constraints.txt /plugins/*; \
+       fi
 
 {{ include_footer }}

etc/kolla/kolla-build.conf

@@ -122,6 +122,17 @@ location = http://tarballs.openstack.org/murano/murano-master.tar.gz
 type = url
 location = http://tarballs.openstack.org/neutron/neutron-master.tar.gz
 
+# The following two blocks show how plugins can be installed into supported
+# images. Note, configuration will need to be provided via Ansible.
+#
+#[neutron-server-plugin-networking-arista]
+#type = url
+#location = http://tarballs.openstack.org/networking-arista/networking-arista-master.tar.gz
+
+#[neutron-server-plugin-networking-brocade]
+#type = url
+#location = http://tarballs.openstack.org/networking-brocade/networking-brocade-master.tar.gz
+
 [nova-base]
 type = url
 location = http://tarballs.openstack.org/nova/nova-master.tar.gz