feat(controller): allow tags for deis pull

if the source Build object specifies a tag to be pulled, it will use
that tag as the source rather than `latest`.

Author: Matthew Fisher

api/models.py

@@ -482,6 +482,11 @@ def new(self, user, config=None, build=None, summary=None, source_version='lates
             tasks.import_repository.delay(build.image, self.app.id).get()
             # update the source image to the repository we just imported
             source_image = self.app.id
+            # if the image imported had a tag specified, use that tag as the source
+            if ':' in build.image:
+                if '/' not in build.image[build.image.rfind(':') + 1:]:
+                    source_image += build.image[build.image.rfind(':'):]
+
         publish_release(source_image,
                         config.values,
                         release_image,)

registry/private.py

@@ -23,9 +23,11 @@ def publish_release(source, config, target):
     contains the new configuration as ENV entries.
     """
     try:
-        if source.count(':') == 2:
-            src_image = source.rsplit(':', 1)[0].split('/', 1)[1]
-            src_tag = source.split(':')[2]
+        # parse for the tag and the repository
+        if ':' in source:
+            if '/' not in source[source.rfind(':') + 1:]:
+                src_tag = source[source.rfind(':') + 1:]
+                src_image = source[:source.rfind(':')]
         else:
             src_image = source
             src_tag = 'latest'