prc_configuring-custom-heat-resource-plugins.adoc

Configuring custom Heat resource plugins

You can deploy custom Heat resource plugins to extend the orchestration service with custom resource types. This procedure uses the extraMounts feature to mount plugin files into the heat-engine pods. For information about writing Heat plugins, refer to the upstream Heat documentation.

Prerequisites

• A deployed OpenStack control plane with Heat enabled.

• Access to the OpenShift cluster with oc CLI.

• Your custom Heat plugin Python file(s).

Procedure

Create a ConfigMap containing your plugin files and mount it into the heat-engine pods using extraMounts.

1. Create a ConfigMap containing your custom Heat plugin:

   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: heat-custom-plugins
     namespace: openstack
   data:
     my_custom_resource.py: |
       <your_plugin_code>

   • Replace <your_plugin_code> with your custom Heat plugin Python code.

2. Apply the ConfigMap:

   $ oc apply -f heat-custom-plugins-configmap.yaml

3. Patch the OpenStackControlPlane CR to add extraMounts to the Heat section:

   $ oc patch openstackcontrolplane <controlplane_name> -n openstack --type=merge -p '
   spec:
     heat:
       template:
         extraMounts:
           - name: custom-plugins
             extraVol:
               - extraVolType: heat-plugins
                 volumes:
                   - name: heat-custom-plugins
                     configMap:
                       name: heat-custom-plugins
                 mounts:
                   - name: heat-custom-plugins
                     mountPath: /usr/lib/heat
                     readOnly: true
                 propagation:
                   - HeatEngine
   '

   • Replace <controlplane_name> with your OpenStackControlPlane CR name.

4. Wait for the heat-engine pods to restart:

   $ oc rollout status deployment/heat-engine -n openstack

5. Verify the plugin files are mounted in the heat-engine pod:

   $ oc exec deployment/heat-engine -n openstack -- ls -la /usr/lib/heat/

6. Verify the custom resource type is available:

   $ oc rsh -n openstack openstackclient openstack orchestration resource type list | grep <resource_type>

   • Replace <resource_type> with the resource type name defined in your plugin.

Using a PersistentVolumeClaim for plugins larger than 1 MiB

If your plugin files exceed the 1 MiB ConfigMap size limit, use a PersistentVolumeClaim (PVC) instead.

Procedure

1. Create a PersistentVolumeClaim:

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: heat-custom-plugins
     namespace: openstack
   spec:
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 1Gi

2. Apply the PVC:

   $ oc apply -f heat-custom-plugins-pvc.yaml

3. Copy your plugin files to the PVC using a temporary pod:

   $ oc run copy-plugins --image=registry.access.redhat.com/ubi9/ubi-minimal --restart=Never \
     --overrides='{"spec":{"containers":[{"name":"copy-plugins","image":"registry.access.redhat.com/ubi9/ubi-minimal","command":["sleep","3600"],"volumeMounts":[{"name":"plugins","mountPath":"/plugins"}]}],"volumes":[{"name":"plugins","persistentVolumeClaim":{"claimName":"heat-custom-plugins"}}]}}' \
     -n openstack
   $ oc wait --for=condition=Ready pod/copy-plugins -n openstack
   $ oc cp <local_plugin_path> openstack/copy-plugins:/plugins/
   $ oc delete pod copy-plugins -n openstack

   • Replace <local_plugin_path> with the path to your plugin file or folder.

4. Patch the OpenStackControlPlane CR to add extraMounts to the Heat section:

   $ oc patch openstackcontrolplane <controlplane_name> -n openstack --type=merge -p '
   spec:
     heat:
       template:
         extraMounts:
           - name: custom-plugins
             extraVol:
               - extraVolType: heat-plugins
                 volumes:
                   - name: heat-custom-plugins
                     persistentVolumeClaim:
                       claimName: heat-custom-plugins
                 mounts:
                   - name: heat-custom-plugins
                     mountPath: /usr/lib/heat
                     readOnly: true
                 propagation:
                   - HeatEngine
   '

   • Replace <controlplane_name> with your OpenStackControlPlane CR name.

5. Wait for the heat-engine pods to restart:

   $ oc rollout status deployment/heat-engine -n openstack

6. Verify the plugin files are mounted in the heat-engine pod:

   $ oc exec deployment/heat-engine -n openstack -- ls -la /usr/lib/heat/

7. Verify the custom resource type is available:

   $ oc rsh -n openstack openstackclient openstack orchestration resource type list | grep <resource_type>

   • Replace <resource_type> with the resource type name defined in your plugin.