Rewrite test_hook_docker_cmd to avoid paunch internals

This test breaks frequently as it is asserting the docker calls which
paunch is making internally. These calls are changing often, as paunch
is in active development.

This change rewrites the test to be a unit test of hook-docker-cmd.py
specifically, with calls to paunch.apply mocked out.

Change-Id: Ieeef3e5916e46d006a358f132bbd64f3960e1fcd
Task: 36342

heat-config-docker-cmd/install.d/hook-docker-cmd.py

@@ -35,23 +35,23 @@ def build_response(deploy_stdout, deploy_stderr, deploy_status_code):
     }
 
 
-def main(argv=sys.argv):
+def main(argv=sys.argv, stdin=sys.stdin, stdout=sys.stdout, stderr=sys.stderr):
     global log
     log = logging.getLogger('heat-config')
-    handler = logging.StreamHandler(sys.stderr)
+    handler = logging.StreamHandler(stderr)
     handler.setFormatter(
         logging.Formatter(
             '[%(asctime)s] (%(name)s) [%(levelname)s] %(message)s'))
     log.addHandler(handler)
     log.setLevel('DEBUG')
 
-    c = json.load(sys.stdin)
+    c = json.load(stdin)
 
     input_values = dict((i['name'], i['value']) for i in c.get('inputs', {}))
 
     if input_values.get('deploy_action') == 'DELETE':
         json.dump(build_response(
-            '', '', 0), sys.stdout)
+            '', '', 0), stdout)
         return
 
     config = c.get('config', '')
@@ -59,11 +59,9 @@ def main(argv=sys.argv):
     if not config:
         log.debug("No 'config' input found, nothing to do.")
         json.dump(build_response(
-            '', '', 0), sys.stdout)
+            '', '', 0), stdout)
         return
 
-    stdout = []
-    stderr = []
     deploy_status_code = 0
 
     # convert config to dict
@@ -73,7 +71,7 @@ def main(argv=sys.argv):
     labels = collections.OrderedDict()
     labels['deploy_stack_id'] = input_values.get('deploy_stack_id')
     labels['deploy_resource_name'] = input_values.get('deploy_resource_name')
-    stdout, stderr, deploy_status_code = paunch.apply(
+    apply_stdout, apply_stderr, deploy_status_code = paunch.apply(
         cid,
         config,
         'docker-cmd',
@@ -82,7 +80,9 @@ def main(argv=sys.argv):
     )
 
     json.dump(build_response(
-        '\n'.join(stdout), '\n'.join(stderr), deploy_status_code), sys.stdout)
+        '\n'.join(apply_stdout),
+        '\n'.join(apply_stderr),
+        deploy_status_code), stdout)
 
 if __name__ == '__main__':
     sys.exit(main(sys.argv))

tests/hook_docker_cmd.py

@@ -0,0 +1 @@
+../heat-config-docker-cmd/install.d/hook-docker-cmd.py