Merge pull request #1076 from deis/1072-rollback

fix(controller): add source release version

Author: Matthew Fisher

controller/api/models.py

@@ -454,7 +454,7 @@ class Meta:
     def __str__(self):
         return "{0}-v{1}".format(self.app.id, self.version)
 
-    def new(self, user, config=None, build=None, summary=None):
+    def new(self, user, config=None, build=None, summary=None, source_version=None):
         """
         Create a new application release using the provided Build and Config
         on behalf of a user.
@@ -465,6 +465,10 @@ def new(self, user, config=None, build=None, summary=None):
             config = self.config
         if not build:
             build = self.build
+        if not source_version:
+            source_version = 'latest'
+        else:
+            source_version = 'v{}'.format(source_version)
         # prepare release tag
         new_version = self.version + 1
         tag = 'v{}'.format(new_version)
@@ -475,7 +479,10 @@ def new(self, user, config=None, build=None, summary=None):
             build=build, version=new_version, image=image, summary=summary)
         # publish release to registry as new docker image
         repository_path = self.app.id
-        publish_release(repository_path, config.values, tag)
+        publish_release(repository_path,
+                        config.values,
+                        tag,
+                        source_tag=source_version)
         return release
 
     def previous(self):

controller/api/views.py

@@ -424,7 +424,11 @@ def rollback(self, request, *args, **kwargs):
         summary = "{} rolled back to v{}".format(request.user, version)
         prev = app.release_set.get(version=version)
         new_release = release.new(
-            request.user, build=prev.build, config=prev.config, summary=summary)
+            request.user,
+            build=prev.build,
+            config=prev.config,
+            summary=summary,
+            source_version=version)
         app.deploy(new_release)
         msg = "Rolled back to v{}".format(version)
         return Response(msg, status=status.HTTP_201_CREATED)

controller/registry/mock.py

@@ -1,5 +1,5 @@
 
-def publish_release(repository_path, config, tag):
+def publish_release(repository_path, config, tag, source_tag='latest'):
     """
     Publish a new release as a Docker image
 

controller/registry/private.py

@@ -9,23 +9,30 @@
 from django.conf import settings
 
 
-def publish_release(repository_path, config, tag):
+def publish_release(repository_path, config, tag, source_tag='latest'):
     """
     Publish a new release as a Docker image
 
     Given a source repository path, a dictionary of environment variables
     and a target tag, create a new lightweight Docker image on the registry.
 
+    source_tag is the name of the previous older tag that this image should
+    be a child of. In most cases, this should be 'latest', but for rollbacks
+    this should be an older tag.
+
     For example, publish_release('gabrtv/myapp', {'ENVVAR': 'values'}, 'v23')
     results in a new Docker image at: <registry_url>/gabrtv/myapp:v23
     which contains the new configuration as ENV entries.
     """
     try:
-        image_id = _get_tag(repository_path, 'latest')
+        image_id = _get_tag(repository_path, source_tag)
     except RuntimeError:
-        # no image exists yet, so let's build one!
-        _put_first_image(repository_path)
-        image_id = _get_tag(repository_path, 'latest')
+        if source_tag == 'latest':
+            # no image exists yet, so let's build one!
+            _put_first_image(repository_path)
+            image_id = _get_tag(repository_path, 'latest')
+        else:
+            raise
     image = _get_image(image_id)
     # construct the new image
     image['parent'] = image['id']