docker image environment variables

Still unable to recognize correct
environment variables in docker
image build process.

Change-Id: I627f6ce281fd79473e857626bcd736e8ba7b34d7

Makefile

@@ -27,7 +27,6 @@ RANGER_USER                ?= ranger
 
 IMAGE_DIR:=images/$(IMAGE_NAME)
 
-# Build ranger Docker image for this project
 #make images will build and run ranger and rangercli
 .PHONY: images
 images: $(IMAGE_NAME)

tools/zuul/playbooks/docker-image-build.yaml

@@ -57,9 +57,9 @@
 
     - name: Determine tags
       environment:
-        BRANCH: zuul.branch
-        CHANGE: zuul.change
-        COMMIT: zuul.newrev
+        BRANCH: "{{ zuul.branch | default('') }}"
+        CHANGE: "{{ zuul.change | default('')  }}"
+        COMMIT: "{{ zuul.newrev | default('') }}"
         PATCHSET: "{{ zuul.patchset | default('')  }}"
       shell: echo '{{ tags | to_json }}' | python {{ zuul.project.src_dir }}/tools/image_tags.py
       register: image_tags