Support existing persistent volume

.gitignore

@@ -0,0 +1 @@
+*.swp

couchdb/templates/_helpers.tpl

@@ -64,8 +64,6 @@ using `lookup` and `get`. The "key", "ns", and "secretName" keys need to be prov
   {{- end -}}
 {{- end -}}
 
-
-
 {{/*
 Labels used to define Pods in the CouchDB statefulset
 */}}
@@ -102,3 +100,46 @@ Fail if couchdbConfig.couchdb.uuid is undefined
 {{- define "couchdb.uuid" -}}
 {{- required "A value for couchdbConfig.couchdb.uuid must be set" (.Values.couchdbConfig.couchdb | default dict).uuid -}}
 {{- end -}}
+
+{{/*
+Repurpose volume claim metadata whether using the new volume claim template
+or existing volume claims.
+*/}}
+{{- define "persistentVolume.metadata" -}}
+{{- $context := index . "context" -}}
+{{- $claim := index . "claim" -}}
+name: {{ $claim.claimName | default "database-storage" }}
+labels:
+  app: {{ template "couchdb.name" $context }}
+  release: {{ $context.Release.Name }}
+{{- with $context.Values.persistentVolume.annotations }}
+annotations:
+  {{- toYaml . | nindent 6 }}
+{{- end }}
+{{- end -}}
+
+{{/*
+Repurpose volume claim spec whether using the new volume claim template
+or an existing volume claim.
+*/}}
+{{- define "persistentVolume.spec" -}}
+{{- $context := index . "context" -}}
+{{- $claim := index . "claim" -}}
+accessModes:
+{{- range $context.Values.persistentVolume.accessModes }}
+- {{ . | quote }}
+{{- end }}
+resources:
+  requests:
+    storage: {{ $context.Values.persistentVolume.size | quote }}
+{{- if $context.Values.persistentVolume.storageClass }}
+{{- if (eq "-" $context.Values.persistentVolume.storageClass) }}
+storageClassName: ""
+{{- else }}
+storageClassName: "{{ $context.Values.persistentVolume.storageClass }}"
+{{- end }}
+{{- end }}
+{{- if $claim.persistentVolumeName }}
+volumeName: {{ $claim.persistentVolumeName }}
+{{- end }}
+{{- end -}}

couchdb/templates/persistentvolume.yaml

@@ -0,0 +1,24 @@
+{{- if and .Values.persistentVolume.enabled .Values.persistentVolume.existingClaims -}}
+{{- range $claim := .Values.persistentVolume.existingClaims }}
+apiVersion: v1
+kind: PersistentVolume
+metadata:
+  name: {{ $claim.persistentVolumeName }}
+spec:
+{{- if $.Values.persistentVolume.storageClass }}
+{{- if (eq "-" $.Values.persistentVolume.storageClass) }}
+  storageClassName: ""
+{{- else }}
+  storageClassName: "{{ $.Values.persistentVolume.storageClass }}"
+{{- end }}
+{{- end }}
+  accessModes:
+  {{- range $.Values.persistentVolume.accessModes }}
+    - {{ . | quote }}
+  {{- end }}
+  capacity:
+    storage: {{ $.Values.persistentVolume.size }}
+{{ toYaml $claim.volumeSource | indent 2 }}
+---
+{{- end }}
+{{- end }}

couchdb/templates/persistentvolumeclaim.yaml

@@ -0,0 +1,12 @@
+{{- if and .Values.persistentVolume.enabled .Values.persistentVolume.existingClaims -}}
+{{- $context := . }}
+{{- range $claim := .Values.persistentVolume.existingClaims }}
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  {{- include "persistentVolume.metadata" (dict "context" $context "claim" $claim) | nindent 2 }}
+spec:
+  {{- include "persistentVolume.spec" (dict "context" $context "claim" $claim) | nindent 2 }}
+---
+{{- end }}
+{{- end }}

couchdb/templates/statefulset.yaml

@@ -207,30 +207,16 @@ spec:
 {{- if not .Values.persistentVolume.enabled }}
         - name: database-storage
           emptyDir: {}
+{{- else if and .Values.persistentVolume.enabled .Values.persistentVolume.existingClaims }}
+        {{- range $claim := .Values.persistentVolume.existingClaims }}
+        - name: {{ $claim.volumeName }}
+          persistentVolumeClaim:
+            claimName: {{ $claim.claimName }}
+        {{- end }}
 {{- else }}
   volumeClaimTemplates:
     - metadata:
-        name: database-storage
-        labels:
-          app: {{ template "couchdb.name" . }}
-          release: {{ .Release.Name }}
-        {{- with .Values.persistentVolume.annotations }}
-        annotations:
-          {{- toYaml . | nindent 10 }}
-        {{- end }}
+        {{- include "persistentVolume.metadata" (dict "context" .) | nindent 8 }}
       spec:
-        accessModes:
-        {{- range .Values.persistentVolume.accessModes }}
-          - {{ . | quote }}
-        {{- end }}
-        resources:
-          requests:
-            storage: {{ .Values.persistentVolume.size | quote }}
-      {{- if .Values.persistentVolume.storageClass }}
-      {{- if (eq "-" .Values.persistentVolume.storageClass) }}
-        storageClassName: ""
-      {{- else }}
-        storageClassName: "{{ .Values.persistentVolume.storageClass }}"
-      {{- end }}
-      {{- end }}
+        {{- include "persistentVolume.spec" (dict "context" .) | nindent 8 }}
 {{- end }}

couchdb/values.yaml

@@ -67,6 +67,8 @@ serviceAccount:
 # provisioner.
 persistentVolume:
   enabled: false
+  # NOTE: the number of existing claims must match the cluster size
+  existingClaims: []
   annotations: {}
   accessModes:
     - ReadWriteOnce