viking-test-app chart supports ExternalName Services.

charts/viking-test-app/templates/deployment.yaml

 {{ range $name, $app := .Values.apps }}
+{{- if not $app.externalName -}}
 apiVersion: apps/v1
 kind: Deployment
 metadata:
@@ -6,6 +7,9 @@ metadata:
     app.kubernetes.io/name: {{ $name }}
     app.kubernetes.io/component: ingressBackend
     {{- include "viking-ingress.labels" $ | nindent 4 }}
+    {{- with $app.labels }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
   name: {{ $name }}
 spec:
   replicas: {{ default "1" $app.replicas }}
@@ -13,12 +17,18 @@ spec:
     matchLabels:
       app.kubernetes.io/name: {{ $name }}
       app.kubernetes.io/instance: {{ $.Release.Name }}
+      {{- with $app.labels }}
+      {{- toYaml . | nindent 6 }}
+      {{- end }}
   template:
     metadata:
       labels:
         app.kubernetes.io/name: {{ $name }}
         app.kubernetes.io/component: ingressBackend
         {{- include "viking-ingress.labels" $ | nindent 8 }}
+        {{- with $app.labels }}
+        {{- toYaml . | nindent 8 }}
+        {{- end }}
     spec:
       containers:
       - name: {{ $name }}
@@ -26,4 +36,5 @@ spec:
         ports:
         - containerPort: {{ default "80" $app.containerPort }}
 ---
-{{ end }}
+{{- end }}
+{{- end }}

charts/viking-test-app/templates/service.yaml

@@ -8,6 +8,10 @@ metadata:
     {{- include "viking-ingress.labels" $ | nindent 4 }}
   name: {{ $name }}-svc
 spec:
+  {{- if $app.externalName }}
+  type: ExternalName
+  externalName: {{ $app.externalName }}
+  {{- end }}
   ports:
   - port: {{ default "80" $app.servicePort }}
     targetPort: {{ default "80" $app.targetPort }}
@@ -17,5 +21,8 @@ spec:
     app.kubernetes.io/name: {{ $name }}
     app.kubernetes.io/component: ingressBackend
     app.kubernetes.io/instance: {{ $.Release.Name }}
+    {{- with $app.labels }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
 ---
 {{ end }}

charts/viking-test-app/values.yaml

@@ -16,6 +16,11 @@ apps: {}
     # If non-empty, contains a BackendConfig for this app.
     # config: {}
 
+    # If non-empty, then a Service of type ExternalName is
+    # generated, with the value as the external name. No
+    # Deployment is generated.
+    # externalName: ""
+
 ingress:
   # Must match the Ingress class observed by the controller.
   class: "varnish"