Bug 1929136: OpenStack: document Manila share mounting

docs/user/openstack/connect_nodes_to_manila_network.md

@@ -0,0 +1,35 @@
+# Connecting nodes to a dedicated Manila network
+
+If you are going to use OpenStack Manila on your cluster, you should be aware that the service usually uses a standalone network for its shares, and by default the installer does not connect nodes to this network. It causes problems with mounting shares on an already deployed cluster, as there is no route to the network:
+
+```txt
+Mounting command: mount
+Mounting arguments: -t nfs 172.16.32.1:/volumes/_nogroup/891cb5d9-a417-43a5-9d1c-5b160a16e7be /var/lib/kubelet/pods/c36e7573-853a-44f9-99bd-0de630edb3b9/volumes/kubernetes.io~csi/pvc-6b632043-2580-4ada-a634-ae696db4b96c/mount
+Output: mount.nfs: Connection timed out
+```
+
+To connect your workers at the time of installation you can use [additionalNetworkIDs](https://github.com/openshift/installer/blob/master/docs/user/openstack/customization.md#additional-networks) parameter in the install config and set Manila network ID there:
+
+Example OpenShift install config:
+
+```yaml
+...
+compute:
+- name: worker
+  platform:
+    openstack:
+      additionalNetworkIDs:
+      - <manila_network_id>
+...
+```
+
+As day2 operation you need to add new network at `networks` section of your machineset's [provider spec](https://github.com/openshift/installer/blob/master/docs/user/openstack/README.md#defining-a-machineset-that-uses-multiple-networks). After that Cluster API Provider OpenStack will automatically connect your workers to the network.
+
+Example of OpenStack Machine Spec:
+
+```yaml
+networks:
+  ...
+  - uuid: <manila_network_id>
+  ...
+```