Add Google Container Registry to KubernetesCluster

Allow access to Google Container Registry using json key as
a password for docker login. The key is scoped to a specific
Google Cloud Platform Console project and its resources.
Add new field for key.

Partially implements: blueprint k8s-google-registry-support

Change-Id: Ica71d1a48ac7fb75a71497fcbe318d1b9e4e8192

Kubernetes/KubernetesCluster/package/UI/ui.yaml

@@ -64,6 +64,7 @@ Application:
   gatewayNodes: repeat($gatewayNode, $.appConfiguration.maxGatewayCount)
   dockerRegistry: $.appConfiguration.dockerRegistry
   dockerMirror: $.appConfiguration.dockerMirror
+  gcloudKey: $.appConfiguration.gcloudKey
 
 
 Forms:
@@ -175,6 +176,16 @@ Forms:
             URL of Docker registry mirror to use.
             Leave empty to not use one.
           required: false
+        - name: gcloudKey
+          type: string
+          label: Google registry key
+          regexpValidator: '^{(\s*"(\\(["\\\/bfnrt]|u[a-fA-F0-9]{4})|[^"\\\0-\x1F\x7F]+)*"\s*:\s*"(\\(["\\\/bfnrt]|u[a-fA-F0-9]{4})|[^"\\\0-\x1F\x7F]+)*"\s*(,|\s*}$))*$'
+          errorMessages:
+            invalid: Text should be a valid JSON.
+          description: >-
+            Contents of JSON key file.
+            Used to authenticate to the Google Container Registry
+          required: false
 
   - instanceConfiguration:
       fields: