Add ability to cancel builds that are in the waiting state

data/database.py

@@ -473,6 +473,7 @@ class BUILD_PHASE(object):
   PULLING = 'pulling'
   BUILDING = 'building'
   PUSHING = 'pushing'
+  WAITING = 'waiting'
   COMPLETE = 'complete'
 
 
@@ -491,7 +492,7 @@ class RepositoryBuild(BaseModel):
   access_token = ForeignKeyField(AccessToken)
   resource_key = CharField(index=True)
   job_config = TextField()
-  phase = CharField(default='waiting')
+  phase = CharField(default=BUILD_PHASE.WAITING)
   started = DateTimeField(default=datetime.now)
   display_name = CharField()
   trigger = ForeignKeyField(RepositoryBuildTrigger, null=True, index=True)

data/model/legacy.py

@@ -14,7 +14,7 @@ from data.database import (User, Repository, Image, AccessToken, Role, Repositor
                            ExternalNotificationEvent, ExternalNotificationMethod,
                            RepositoryNotification, RepositoryAuthorizedEmail, TeamMemberInvite,
                            DerivedImageStorage, ImageStorageTransformation, random_string_generator,
-                           db, BUILD_PHASE, QuayUserField, ImageStorageSignature,
+                           db, BUILD_PHASE, QuayUserField, ImageStorageSignature, QueueItem,
                            ImageStorageSignatureKind, validate_database_url, db_for_update)
 from peewee import JOIN_LEFT_OUTER, fn
 from util.validation import (validate_username, validate_email, validate_password,
@@ -2431,6 +2431,32 @@ def confirm_team_invite(code, user):
   found.delete_instance()
   return (team, inviter)
 
+def cancel_repository_build(build):
+  with config.app_config['DB_TRANSACTION_FACTORY'](db):
+    # Reload the build for update.
+    try:
+      build = db_for_update(RepositoryBuild.select().where(RepositoryBuild.id == build.id)).get()
+    except RepositoryBuild.DoesNotExist:
+      return False
+
+    if build.phase != BUILD_PHASE.WAITING or not build.queue_item:
+      return False
+
+    # Load the build queue item for update.
+    try:
+      queue_item = db_for_update(QueueItem.select()
+                                          .where(QueueItem.id == build.queue_item.id)).get()
+    except QueueItem.DoesNotExist:
+      return False
+
+    # Check the queue item.
+    if not queue_item.available or queue_item.retries_remaining == 0:
+      return False
+
+    # Delete the queue item and build.
+    queue_item.delete_instance(recursive=True)
+    build.delete_instance()
+    return True
 
 def get_repository_usage():
   one_month_ago = date.today() - timedelta(weeks=4)