Add easy way to override default container registry

Signed-off-by: Pat Riehecky <riehecky@fnal.gov>

pkg/chartutil/create.go

@@ -110,6 +110,7 @@ const defaultValues = `# Default values for %s.
 replicaCount: 1
 
 image:
+  registry: ""
   repository: nginx
   pullPolicy: IfNotPresent
   # Overrides the image tag whose default is the chart appVersion.
@@ -308,7 +309,11 @@ spec:
         - name: {{ .Chart.Name }}
           securityContext:
             {{- toYaml .Values.securityContext | nindent 12 }}
+          {{- if .Values.image.registry }}
+          image: "{{ .Values.image.registry }}/{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
+          {{- else }} 
           image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
+          {{- end }}
           imagePullPolicy: {{ .Values.image.pullPolicy }}
           ports:
             - name: http