Overview of the access controls


There are two layers of access control in Swarming: the first is a global layer that controls user permissions globally for the server, and the second is a bot pool layer, that controls who exactly can trigger tasks on what bot pools.

The second layer is optional and by default it is turned off, meaning anyone that has global “can trigger a task” permission can trigger tasks on any bots connected to the server. Details of how to turn it on and how it behaves are described at the end of this doc.

Global access control is implemented via roles that are defined by the access control groups, and are managed by going to the /auth URL of your app. In a fresh instance, group names default to administrators, so only those can use the service. To get started:

  • Configure the group names for each role in the configuration file; see the config_service for details, and AuthSettings in proto/config/config.proto for the schema.
  • Create the appropriate groups under /auth.
  • Add relevant users and IPs to the groups. Make sure that users who have access to the Swarming server also have equivalent access to the RBE-CAS server.

When specifying members of the auth groups, you can refer to the IPs in the allowlist using bots:*. For individual user accounts simply use their email, e.g. user@example.org. All users in a domain can be specified with a glob, e.g. *@chromium.org.

Groups that define global server ACLs


Members of this group can:

  • Trigger a task.
  • Query tasks the user triggered and get results.
  • List the tasks they triggered.
  • Cancel their own tasks.

Members have limited visibility over the whole system, and cannot view other user tasks or bots.


Members of this group can do everything that members of the users_group can do plus:

  • See other people's tasks.
  • See all the bots connected.


Members of this group can fetch Swarming bot code and bootstrap bots.


Members of this group can do all of the above plus:

  • Cancel anyone's task.
  • Delete bots.
  • Update bootstrap.py and bot_config.py.

Pool ACLs

See http://go/luci-authorization#swarming-permissions for the LUCI Relam explanation.

A bot pool is a named collection of bots usually dedicated to some single kind of workload or a single project. Swarming assigns bots to pools by forcibly setting pool:<name> dimension on them based on configuration defined in bots.cfg config file (see proto/config/bots.proto).

Pool ACLs specify who is allowed to trigger tasks in a pool. This is a second layer of ACLs that is consulted when triggering new tasks (and only then) after the request passes the first server-global layer.

Only the triggering authorization can be controlled with a finer precision, everything else is controlled through server global groups described above.

Pool ACLs are defined in pools.cfg config file (see proto/config/pools.proto). If this file is missing or empty, pool ACLs are completely disabled for the service, meaning only the server-global ACLs are consulted.