[helm] use existing pvc claim of provided (#547)

helm/opengist/templates/deployment.yaml

@@ -95,7 +95,11 @@ spec:
         - name: opengist-data
           {{- if .Values.persistence.enabled }}
           persistentVolumeClaim:
+            {{- if .Values.persistence.existingClaim }}
+            claimName: {{ .Values.persistence.existingClaim }}
+            {{- else }}
             claimName: {{ include "opengist.fullname" . }}-data
+            {{- end }}
           {{- else }}
           emptyDir: {}
           {{- end }}

helm/opengist/templates/pvc.yaml

@@ -1,4 +1,4 @@
-{{- if .Values.persistence.enabled }}
+{{- if and .Values.persistence.enabled (not .Values.persistence.existingClaim) }}
 kind: PersistentVolumeClaim
 apiVersion: v1
 metadata: