Add ability to add default dockerfile

Author: thejsj

ansible/group_vars/alpha-image-builder.yml

@@ -5,6 +5,7 @@ inject_ca: false
 repo: git@github.com:CodeNow/{{ name }}.git
 node_version: "4.8.0"
 npm_version: "2.15.11"
+use_default_dockerfile: true
 
 # consul values
 consul_values:

ansible/roles/builder/tasks/main.yml

@@ -91,7 +91,7 @@
 - name: copy dockerfile to build folder
   delegate_to: "{{ builder }}"
   tags: deploy, build
-  when: build_image
+  when: build_image and use_default_dockerfile is not defined
   become: true
   template:
     src: "{{ dockerfile }}"