Buildbot makes heavy use of Twisted Python's support for services - software modules that can be started and stopped dynamically. Buildbot adds the ability to reconfigure such services, too - see :ref:`developer-reconfiguration`. Twisted arranges services into trees; the following section describes the service tree on a running master.
The hierarchy begins with the master, a :py:class:`buildbot.master.BuildMaster`
instance. Most other services contain a reference to this object in their
master attribute, and in general the appropriate way to access other
objects or services is to begin with self.master and navigate from there.
The master has a number of useful attributes:
master.metrics- A :py:class:`buildbot.process.metrics.MetricLogObserver` instance that handles tracking and reporting on master metrics.
master.caches- A :py:class:`buildbot.process.caches.CacheManager` instance that provides access to object caches.
master.pbmanager- A :py:class:`buildbot.pbmanager.PBManager` instance that handles incoming PB connections, potentially on multiple ports, and dispatching those connections to appropriate components based on the supplied username.
master.workers- A :py:class:`buildbot.worker.manager.WorkerManager` instance that provides wrappers around multiple master-worker protocols (e.g. PB) to unify calls for them from higher level code.
master.change_svc- A :py:class:`buildbot.changes.manager.ChangeManager` instance that manages the active change sources, as well as the stream of changes received from those sources. All active change sources are child services of this instance.
master.botmasterA :py:class:`buildbot.process.botmaster.BotMaster` instance that manages all of the workers and builders as child services.
The botmaster acts as the parent service for a :py:class:`buildbot.process.botmaster.BuildRequestDistributor` instance (at
master.botmaster.brd), as well as all active workers (:py:class:`buildbot.worker.AbstractWorker` instances) and builders (:py:class:`buildbot.process.builder.Builder` instances).master.scheduler_manager- A :py:class:`buildbot.schedulers.manager.SchedulerManager` instance that manages the active schedulers. All active schedulers are child services of this instance.
master.user_manager- A :py:class:`buildbot.process.users.manager.UserManagerManager` instance that manages access to users. All active user managers are child services of this instance.
master.db- A :py:class:`buildbot.db.connector.DBConnector` instance that manages access to the buildbot database. See :ref:`developer-database` for more information.
master.debug- A :py:class:`buildbot.process.debug.DebugServices` instance that manages debugging-related access -- the manhole, in particular.
master.masterid- This is the ID for this master, from the
masterstable. It is used in the database and messages to uniquely identify this master.