buildbucket: add retry API.

appengine/cr-buildbucket/service.py

Index: appengine/cr-buildbucket/service.py
diff --git a/appengine/cr-buildbucket/service.py b/appengine/cr-buildbucket/service.py
index f13cef7dc623ef0107c84caab2ff78104d317044..bd2845bb6d24b8bc130e12e71ab7e4f8c8c120bd 100644
--- a/appengine/cr-buildbucket/service.py
+++ b/appengine/cr-buildbucket/service.py
@@ -182,6 +182,23 @@ def add(*args, **kwargs):
   return add_async(*args, **kwargs).get_result()
 
 
+def retry(
+    build_id, lease_expiration_date=None, client_operation_id=None,
+    pubsub_callback=None):
+  """Adds a build with same bucket, parameters and tags as the given one."""
+  build = model.Build.get_by_id(build_id)
+  if not build:
+    raise errors.BuildNotFoundError('Build %s not found' % build_id)
+  return add(
+    build.bucket,
+    tags=build.tags + ['retry_of:%s' % build_id],

[Vadim Sh., 2016/04/12 00:02:13]

well.. if you want to use server-side provided tags you must make sure clients
can't override them

[nodir, 2016/04/12 13:32:43]

Done.

+    parameters=build.parameters,
+    lease_expiration_date=lease_expiration_date,
+    client_operation_id=client_operation_id,
+    pubsub_callback=pubsub_callback,
+  )
+
+
 def get(build_id):
   """Gets a build by |build_id|.