Add command-line opt to enable gitlab-rebase

marge/app.py

@@ -110,6 +110,15 @@ def regexp(str_regex):
             'to use merge commits on the *target* branch (the default).)\n'
         ),
     )
+    parser.add_argument(
+        '--rebase-remotely',
+        action='store_true',
+        help=(
+            "Instead of rebasing in a local clone of the repository, use GitLab's\n"
+            "built-in rebase functionality, via their API. Note that Marge can't add\n"
+            "information in the commits in this case.\n"
+        ),
+    ),
     parser.add_argument(
         '--add-tested',
         action='store_true',
@@ -199,6 +208,16 @@ def regexp(str_regex):
         raise MargeBotCliArgError('--use-merge-strategy and --batch are currently mutually exclusive')
     if config.use_merge_strategy and config.add_tested:
         raise MargeBotCliArgError('--use-merge-strategy and --add-tested are currently mutually exclusive')
+    if config.rebase_remotely:
+        conflicting_flag = [
+            '--use-merge-strategy',
+            '--add-tested',
+            '--add-reviewers',
+            '--add-part-of',
+        ]
+        for flag in conflicting_flag:
+            if getattr(config, flag[2:].replace("-", "_")):
+                raise MargeBotCliArgError('--rebase-remotely and %s are mutually exclusive' % flag)
 
     cli_args = []
     # pylint: disable=protected-access
@@ -252,6 +271,14 @@ def main(args=None):
 
         if options.use_merge_strategy:
             fusion = bot.Fusion.merge
+        elif options.rebase_remotely:
+            version = api.version()
+            if version.release < (11, 6):
+                raise Exception(
+                    "Need GitLab 11.6+ to use rebase through the API, "
+                    "but your instance is {}".format(version)
+                )
+            fusion = bot.Fusion.gitlab_rebase
         else:
             fusion = bot.Fusion.rebase
 

marge/gitlab.py

@@ -227,3 +227,6 @@ def parse(cls, string):
     @property
     def is_ee(self):
         return self.edition == 'ee'
+
+    def __str__(self):
+        return '%s-%s' % ('.'.join(map(str, self.release)), self.edition)

tests/test_app.py

@@ -65,6 +65,7 @@ def api_mock(gitlab_url, auth_token):
         api = gitlab_mock.Api(gitlab_url=gitlab_url, auth_token=auth_token, initial_state='initial')
         user_info_for_token = dict(user_info, is_admin=auth_token == 'ADMIN-TOKEN')
         api.add_user(user_info_for_token, is_current=True)
+        api.add_transition(gitlab_mock.GET('/version'), gitlab_mock.Ok({'version': '11.6.0-ce'}))
         return api
 
     class DoNothingBot(bot_module.Bot):
@@ -103,6 +104,13 @@ def test_embargo():
             )
 
 
+def test_rebase_remotely():
+    with env(MARGE_AUTH_TOKEN="NON-ADMIN-TOKEN", MARGE_SSH_KEY="KEY", MARGE_GITLAB_URL='http://foo.com'):
+        with main('--rebase-remotely') as bot:
+            assert bot.config.merge_opts != job.MergeJobOptions.default()
+            assert bot.config.merge_opts == job.MergeJobOptions.default(fusion=job.Fusion.gitlab_rebase)
+
+
 def test_use_merge_strategy():
     with env(MARGE_AUTH_TOKEN="NON-ADMIN-TOKEN", MARGE_SSH_KEY="KEY", MARGE_GITLAB_URL='http://foo.com'):
         with main('--use-merge-strategy') as bot:
@@ -142,6 +150,12 @@ def test_add_reviewers():
             assert bot.config.merge_opts != job.MergeJobOptions.default()
             assert bot.config.merge_opts == job.MergeJobOptions.default(add_reviewers=True)
 
+def test_rebase_remotely_option_conflicts():
+    for conflicting_flag in ['--use-merge-strategy', '--add-tested', '--add-part-of', '--add-reviewers']:
+        with env(MARGE_AUTH_TOKEN="NON-ADMIN-TOKEN", MARGE_SSH_KEY="KEY", MARGE_GITLAB_URL='http://foo.com'):
+            with pytest.raises(app.MargeBotCliArgError):
+                with main('--rebase-remotely %s' % conflicting_flag) as bot:
+                    pass
 
 def test_impersonate_approvers():
     with env(MARGE_AUTH_TOKEN="NON-ADMIN-TOKEN", MARGE_SSH_KEY="KEY", MARGE_GITLAB_URL='http://foo.com'):