Add code that will allow build triggers to be deactivated or deleted from their services.

endpoints/trigger.py

@@ -28,6 +28,9 @@ class InvalidServiceException(Exception):
 class TriggerActivationException(Exception):
   pass
 
+class TriggerDeactivationException(Exception):
+  pass
+
 class ValidationRequestException(Exception):
   pass
 
@@ -70,6 +73,15 @@ class BuildTrigger(object):
   def activate(self, trigger_uuid, standard_webhook_url, auth_token, config):
     """ 
     Activates the trigger for the service, with the given new configuration.
+    Returns new configuration that should be stored if successful.
+    """
+    raise NotImplementedError
+
+  def deactivate(self, auth_token, config):
+    """
+    Deactivates the trigger for the service, removing any hooks installed in
+    the remote service. Returns the new config that should be stored if this
+    trigger is going to be re-activated.
     """
     raise NotImplementedError
 
@@ -104,7 +116,7 @@ class GithubBuildTrigger(BuildTrigger):
     return 'github'
 
   def is_active(self, config):
-    return 'build_source' in config and len(config['build_source']) > 0
+    return 'hook_id' in config
 
   def activate(self, trigger_uuid, standard_webhook_url, auth_token, config):
     new_build_source = config['build_source']
@@ -122,11 +134,30 @@ class GithubBuildTrigger(BuildTrigger):
     }
 
     try:
-      to_add_webhook.create_hook('web', webhook_config)
+      hook = to_add_webhook.create_hook('web', webhook_config)
+      config['hook_id'] = hook.id
     except GithubException:
       msg = 'Unable to create webhook on repository: %s'
       raise TriggerActivationException(msg % new_build_source)
 
+    return config
+
+  def deactivate(self, auth_token, config):
+    gh_client = self._get_client(auth_token)
+
+    try:
+      repo = gh_client.get_repo(config['build_source'])
+      to_delete = repo.get_hook(config['hook_id'])
+      to_delete.delete()
+    except GithubException:
+      msg = 'Unable to remove hook: %s' % config['hook_id']
+      raise TriggerDeactivationException(msg)
+
+    config.pop('hook_id', None)
+
+    return config
+
+
   def list_build_sources(self, auth_token):
     gh_client = self._get_client(auth_token)
     usr = gh_client.get_user()