[stable/concourse] Allow the use of a specific image digest (#8910)

* Allow the use of a specific image digest

This allows testing pre-release concourse/dev images without
having to tag them.

Signed-off-by: Topher Bullock <cbullock@pivotal.io>

* [stable/concourse] bump chart version

Signed-off-by: Rui Yang <ryang@pivotal.io>

* Bump chart minor version to 2.1.0

Signed-off-by: Topher Bullock <cbullock@pivotal.io>

stable/concourse/Chart.yaml

@@ -1,5 +1,5 @@
 name: concourse
-version: 2.0.5
+version: 2.1.0
 appVersion: 4.2.1
 description: Concourse is a simple and scalable CI system.
 icon: https://avatars1.githubusercontent.com/u/7809479

stable/concourse/templates/web-deployment.yaml

@@ -26,7 +26,11 @@ spec:
 {{ toYaml .Values.web.tolerations | indent 8 }}
       containers:
         - name: {{ template "concourse.web.fullname" . }}
+          {{- if .Values.imageDigest }}
+          image: "{{ .Values.image }}@{{ .Values.imageDigest }}"
+          {{- else }}
           image: "{{ .Values.image }}:{{ .Values.imageTag }}"
+          {{- end }}
           imagePullPolicy: {{ .Values.imagePullPolicy | quote }}
           args:
             - "web"

stable/concourse/templates/worker-statefulset.yaml

@@ -31,7 +31,11 @@ spec:
       terminationGracePeriodSeconds: {{ .Values.worker.terminationGracePeriodSeconds }}
       containers:
         - name: {{ template "concourse.worker.fullname" . }}
+          {{- if .Values.imageDigest }}
+          image: "{{ .Values.image }}@{{ .Values.imageDigest }}"
+          {{- else }}
           image: "{{ .Values.image }}:{{ .Values.imageTag }}"
+          {{- end }}
           imagePullPolicy: {{ .Values.imagePullPolicy | quote }}
           command:
             - /bin/sh

stable/concourse/values.yaml

@@ -15,6 +15,11 @@ image: concourse/concourse
 ##
 imageTag: "4.2.1"
 
+## Specific image digest to use in place of a tag.
+## ref: https://kubernetes.io/docs/concepts/configuration/overview/#container-images
+##
+# imageDigest: sha256:54ea351808b55ecc14af6590732932e2a6a0ed8f6d10f45e8be3b51165d5526a
+
 ## Specify a imagePullPolicy: 'Always' if imageTag is 'latest', else set to 'IfNotPresent'.
 ## ref: https://kubernetes.io/docs/user-guide/images/#pre-pulling-images
 ##