feat: add support for hostPath volume in indexer

- Adds `hostPath` configuration in `values.yaml` to allow
  using a hostPath volume for the index worker.
- Updates `deployment.yaml` to conditionally use `hostPath` if specified,
  otherwise fallback to `PersistentVolumeClaim`.

Closes #164

helm/templates/deployment.yaml

@@ -133,10 +133,16 @@ spec:
           configMap:
             name: {{ .Release.Name }}-indexer-configfiles
             defaultMode: 0644
-        - name:  indexer-metacat-pv
+        - name: indexer-metacat-pv
+          {{- if and .Values.persistence.hostPath .Values.persistence.hostPath.path }}
+          hostPath:
+            path: {{ tpl .Values.persistence.hostPath.path . }}
+            type: {{ .Values.persistence.hostPath.type }}
+          {{- else }}
           persistentVolumeClaim:
             claimName: {{ include "idxworker.shared.claimName" . }}
             readOnly: true
+          {{- end }}
         - name: {{ .Release.Name }}-temp-tripledb-volume
           ephemeral:
             volumeClaimTemplate:

helm/values.yaml

@@ -124,6 +124,15 @@ persistence:
   ##
   subPath: ""
 
+  ## @param persistence.hostPath Use a hostPath volume for the index worker.
+  ## This will override the claimName and use the mountPath settings.
+  hostPath:
+    ## @param persistence.hostPath.path The path on the host to use for the hostPath volume
+    path: ""
+    ## @param persistence.hostPath.type The type of hostPath volume to use
+    type: Directory
+
+
 ## @section IndexWorker properties
 ##
 idxworker: