Chapter 8. Using the dynamic plugins cache

Procedure

1. Create the persistent volume definition and save it to a file, such as pvc.yaml. For example:

   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     name: dynamic-plugins-root
   spec:
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 5Gi

   Note

   This example uses ReadWriteOnce as the access mode which prevents multiple replicas from sharing the PVC across different nodes. To run multiple replicas on different nodes, depending on your storage driver, you must use an access mode such as ReadWriteMany.

2. To apply this PVC to your cluster, run the following command:

   oc apply -f pvc.yaml

3. Replace the default dynamic-plugins-root volume with a PVC named dynamic-plugins-root. For example:

   apiVersion: rhdh.redhat.com/v1alpha3
   kind: Backstage
   metadata:
     name: developer-hub
   spec:
     deployment:
       patch:
         spec:
           template:
             spec:
               volumes:
                 - $patch: replace
                   name: dynamic-plugins-root
                   persistentVolumeClaim:
                     claimName: dynamic-plugins-root

   Note

   To avoid adding a new volume, you must use the $patch: replace directive.

Procedure

1. Create the persistent volume definition. For example:

   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     name: dynamic-plugins-root
   spec:
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 5Gi

   Note

   This example uses ReadWriteOnce as the access mode which prevents multiple replicas from sharing the PVC across different nodes. To run multiple replicas on different nodes, depending on your storage driver, you must use an access mode such as ReadWriteMany.

2. To apply this PVC to your cluster, run the following command:

   oc apply -f pvc.yaml

3. Configure the Helm chart to use the PVC. For example:

   upstream:
     backstage:
       extraVolumes:
         - name: dynamic-plugins-root
           persistentVolumeClaim:
             claimName: dynamic-plugins-root
         - name: dynamic-plugins
           configMap:
             defaultMode: 420
             name: '{{ printf "%s-dynamic-plugins" .Release.Name }}'
             optional: true
         - name: dynamic-plugins-npmrc
           secret:
             defaultMode: 420
             optional: true
             secretName: '{{ printf "%s-dynamic-plugins-npmrc" .Release.Name }}'
         - name: dynamic-plugins-registry-auth
           secret:
             defaultMode: 416
             optional: true
             secretName: '{{ printf "%s-dynamic-plugins-registry-auth" .Release.Name }}'
         - name: npmcacache
           emptyDir: {}
         - name: temp
           emptyDir: {}

   Note

   When you configure the Helm chart to use the PVC, you must also include the extraVolumes defined in the default Helm chart.