Merge pull request #5705 from mgugino-upstream-stage/docker-partof-iptables

Add PartOf to docker systemd service unit.

roles/docker/templates/custom.conf.j2

@@ -3,3 +3,9 @@
 [Unit]
 Wants=iptables.service
 After=iptables.service
+
+# The following line is a work-around to ensure docker is restarted whenever
+# iptables is restarted.  This ensures the proper iptables rules will be in
+# place for docker.
+# Note:  This will also cause docker to be stopped if iptables is stopped.
+PartOf=iptables.service