[openvswitch] Make --user flag optional

Add the ability to run the OVS server as root
since the following change lacks backward compatibility:
https://review.opendev.org/c/openstack/openstack-helm-infra/+/939580

Change-Id: I071f77be0d329fbe98ce283324466bf129fe190d

openvswitch/templates/bin/_openvswitch-vswitchd.sh.tpl

@@ -119,8 +119,10 @@ function start () {
           -vconsole:err \
           -vconsole:info \
           --pidfile=${OVS_PID} \
-          --mlockall \
-          --user="{{ .Values.conf.ovs_user_name }}"
+          {{- if .Values.conf.ovs_user_name }}
+          --user="{{ .Values.conf.ovs_user_name }}" \
+          {{- end }}
+          --mlockall
 }
 
 function stop () {

openvswitch/values.yaml

@@ -243,6 +243,8 @@ conf:
     # vhost_iommu_support: true
   ## OVS supports run in non-root for both OVS and OVS DPDK mode, the user
   # for OVS need to be added to container image with user id 42424.
-  # useradd -u 42424 openvswitch, groupmod -g 42424 openvswitch
+  # useradd -u 42424 openvswitch; groupmod -g 42424 openvswitch
+  #
+  # Leave empty to run as user that invokes the command (default: root)
   ovs_user_name: "openvswitch:openvswitch"
 ...

releasenotes/notes/openvswitch-e761d6733b84bdc7.yaml

@@ -0,0 +1,4 @@
+---
+openvswitch:
+  - Make the --user flag for OVS server optional
+...