buildbot service architecture

1\

#####
## twiste Service
## setServiceParent  will call addService
#####
twisted_10_2/twisted/application/service.py

class Service:
    ......
    def setServiceParent(self, parent):
        if self.parent is not None:
            self.disownServiceParent()
        parent = IServiceCollection(parent, parent)
        self.parent = parent
        self.parent.addService(self)

2\
#####
## .tac file
#####
masters/master.**/buildbot.tac

application = service.Application('buildmaster')
BuildMaster(basedir, configfile).setServiceParent(application)

3\
#####
## buildbot config
## and buildbot architecture
#####
/masters/master.**/master.cfg
 

c = BuildmasterConfig = {}
c['slavePortnum']  = ActiveMaster.slave_port
c['change_source'] = [devel_branch_poller]
c['schedulers'] = [s_devel_branch]
c['builders']   = [b_devel_linux]
c['slaves'] = master_utils.AutoSetupSlaves(c['builders'],
                                           config.Master.GetBotPassword())

buildbot_8_4p1/buildbot/master.py

class BuildMaster(service.MultiService):

    def loadConfig(self, f, checkOnly=False):
      ......
      def do_load(_):
        ......//read the config
        try:
            config = localDict['BuildmasterConfig']

        ......//load the config
        try:
            schedulers = config['schedulers']
            builders = config['builders']
            slavePortnum = config['slavePortnum']
            slaves = config.get('slaves', [])
            change_source = config.get('change_source', [])

        ......
        # Set up the database
        d.addCallback(lambda res:
                      self.loadConfig_Database(db_url, db_poll_interval))

        # set up slaves
        d.addCallback(lambda res: self.loadConfig_Slaves(slaves))

        # add/remove self.botmaster.builders to match builders. The
        # botmaster will handle startup/shutdown issues.
        d.addCallback(lambda res: self.loadConfig_Builders(builders))

        d.addCallback(lambda res: self.loadConfig_Status(status))

        # Schedulers are added after Builders in case they start right away
        d.addCallback(lambda _: self.loadConfig_Schedulers(schedulers))

        # and Sources go after Schedulers for the same reason
        d.addCallback(lambda res: self.loadConfig_Sources(change_sources))

        # debug client
        d.addCallback(lambda res: self.loadConfig_DebugClient(debugPassword))


    def loadConfig_Schedulers(self, schedulers):
        ......// SchedulerManager object
        timer = metrics.Timer("BuildMaster.loadConfig_Schedulers()")
        timer.start()
        d = self.scheduler_manager.updateSchedulers(schedulers)

4\
#####
## buildbot service architecture
#####

class BuildMaster(service.MultiService):
    def __init__(self, basedir, configFileName="master.cfg"):
        ......
        self.pbmanager.setServiceParent(self)
        self.change_svc.setServiceParent(self)
        self.botmaster.setServiceParent(self)
        self.scheduler_manager.setServiceParent(self)

    def loadDatabase(self, db_url, db_poll_interval=None):
        ......
        self.db.setServiceParent(self)


class SchedulerManager(service.MultiService):
    ......
    def updateSchedulers(self, newschedulers):
        def startScheduler(sch):
            class_name = '%s.%s' % (sch.__class__.__module__,
                                    sch.__class__.__name__)
            class_name = new_class_names.get(class_name, class_name)
            d = self.master.db.schedulers.getSchedulerId(sch.name, class_name)
            d.addCallback(lambda schedulerid :
                    sch._setUpScheduler(schedulerid, self.master, self))
            d.addCallback(lambda _ :
                    sch.setServiceParent(self))
            return d
        d.addCallback(lambda _ :
            defer.gatherResults([startScheduler(new[n]) for n in added_names]))

summary=================================================

1\ buildbot的结构为树状，MultiService包含多个MultiService,子MultiService还能包含其他的service.
2\ SchedulerManager BuildMaster.loadConfig()读配置文件，

service 见
http://twistedmatrix.com/documents/current/core/howto/tutorial/protocol.html