path: root/buildbot/buildbot/scheduler.py

# -*- test-case-name: buildbot.test.test_dependencies -*-

import time, os.path

from zope.interface import implements
from twisted.internet import reactor
from twisted.application import service, internet, strports
from twisted.python import log, runtime
from twisted.protocols import basic
from twisted.cred import portal, checkers
from twisted.spread import pb

from buildbot import interfaces, buildset, util, pbutil
from buildbot.status import builder
from buildbot.sourcestamp import SourceStamp
from buildbot.changes.maildir import MaildirService
from buildbot.process.properties import Properties


class BaseScheduler(service.MultiService, util.ComparableMixin):
    """
    A Schduler creates BuildSets and submits them to the BuildMaster.

    @ivar name: name of the scheduler

    @ivar properties: additional properties specified in this 
        scheduler's configuration
    @type properties: Properties object
    """
    implements(interfaces.IScheduler)

    def __init__(self, name, properties={}):
        """
        @param name: name for this scheduler

        @param properties: properties to be propagated from this scheduler
        @type properties: dict
        """
        service.MultiService.__init__(self)
        self.name = name
        self.properties = Properties()
        self.properties.update(properties, "Scheduler")
        self.properties.setProperty("scheduler", name, "Scheduler")

    def __repr__(self):
        # TODO: why can't id() return a positive number? %d is ugly.
        return "<Scheduler '%s' at %d>" % (self.name, id(self))

    def submitBuildSet(self, bs):
        self.parent.submitBuildSet(bs)

    def addChange(self, change):
        pass

class BaseUpstreamScheduler(BaseScheduler):
    implements(interfaces.IUpstreamScheduler)

    def __init__(self, name, properties={}):
        BaseScheduler.__init__(self, name, properties)
        self.successWatchers = []

    def subscribeToSuccessfulBuilds(self, watcher):
        self.successWatchers.append(watcher)
    def unsubscribeToSuccessfulBuilds(self, watcher):
        self.successWatchers.remove(watcher)

    def submitBuildSet(self, bs):
        d = bs.waitUntilFinished()
        d.addCallback(self.buildSetFinished)
        BaseScheduler.submitBuildSet(self, bs)

    def buildSetFinished(self, bss):
        if not self.running:
            return
        if bss.getResults() == builder.SUCCESS:
            ss = bss.getSourceStamp()
            for w in self.successWatchers:
                w(ss)


class Scheduler(BaseUpstreamScheduler):
    """The default Scheduler class will run a build after some period of time
    called the C{treeStableTimer}, on a given set of Builders. It only pays
    attention to a single branch. You you can provide a C{fileIsImportant}
    function which will evaluate each Change to decide whether or not it
    should trigger a new build.
    """

    fileIsImportant = None
    compare_attrs = ('name', 'treeStableTimer', 'builderNames', 'branch',
                     'fileIsImportant', 'properties', 'categories')
    
    def __init__(self, name, branch, treeStableTimer, builderNames,
                 fileIsImportant=None, properties={}, categories=None):
        """
        @param name: the name of this Scheduler
        @param branch: The branch name that the Scheduler should pay
                       attention to. Any Change that is not on this branch
                       will be ignored. It can be set to None to only pay
                       attention to the default branch.
        @param treeStableTimer: the duration, in seconds, for which the tree
                                must remain unchanged before a build will be
                                triggered. This is intended to avoid builds
                                of partially-committed fixes.
        @param builderNames: a list of Builder names. When this Scheduler
                             decides to start a set of builds, they will be
                             run on the Builders named by this list.

        @param fileIsImportant: A callable which takes one argument (a Change
                                instance) and returns True if the change is
                                worth building, and False if it is not.
                                Unimportant Changes are accumulated until the
                                build is triggered by an important change.
                                The default value of None means that all
                                Changes are important.

        @param properties: properties to apply to all builds started from this 
                           scheduler
        @param categories: A list of categories of changes to accept
        """

        BaseUpstreamScheduler.__init__(self, name, properties)
        self.treeStableTimer = treeStableTimer
        errmsg = ("The builderNames= argument to Scheduler must be a list "
                  "of Builder description names (i.e. the 'name' key of the "
                  "Builder specification dictionary)")
        assert isinstance(builderNames, (list, tuple)), errmsg
        for b in builderNames:
            assert isinstance(b, str), errmsg
        self.builderNames = builderNames
        self.branch = branch
        if fileIsImportant:
            assert callable(fileIsImportant)
            self.fileIsImportant = fileIsImportant

        self.importantChanges = []
        self.unimportantChanges = []
        self.nextBuildTime = None
        self.timer = None
        self.categories = categories

    def listBuilderNames(self):
        return self.builderNames

    def getPendingBuildTimes(self):
        if self.nextBuildTime is not None:
            return [self.nextBuildTime]
        return []

    def addChange(self, change):
        if change.branch != self.branch:
            log.msg("%s ignoring off-branch %s" % (self, change))
            return
        if self.categories is not None and change.category not in self.categories:
            log.msg("%s ignoring non-matching categories %s" % (self, change))
            return
        if not self.fileIsImportant:
            self.addImportantChange(change)
        elif self.fileIsImportant(change):
            self.addImportantChange(change)
        else:
            self.addUnimportantChange(change)

    def addImportantChange(self, change):
        log.msg("%s: change is important, adding %s" % (self, change))
        self.importantChanges.append(change)
        self.nextBuildTime = max(self.nextBuildTime,
                                 change.when + self.treeStableTimer)
        self.setTimer(self.nextBuildTime)

    def addUnimportantChange(self, change):
        log.msg("%s: change is not important, adding %s" % (self, change))
        self.unimportantChanges.append(change)

    def setTimer(self, when):
        log.msg("%s: setting timer to %s" %
                (self, time.strftime("%H:%M:%S", time.localtime(when))))
        now = util.now()
        if when < now:
            when = now
        if self.timer:
            self.timer.cancel()
        self.timer = reactor.callLater(when - now, self.fireTimer)

    def stopTimer(self):
        if self.timer:
            self.timer.cancel()
            self.timer = None

    def fireTimer(self):
        # clear out our state
        self.timer = None
        self.nextBuildTime = None
        changes = self.importantChanges + self.unimportantChanges
        self.importantChanges = []
        self.unimportantChanges = []

        # create a BuildSet, submit it to the BuildMaster
        bs = buildset.BuildSet(self.builderNames,
                               SourceStamp(changes=changes),
                               properties=self.properties)
        self.submitBuildSet(bs)

    def stopService(self):
        self.stopTimer()
        return service.MultiService.stopService(self)


class AnyBranchScheduler(BaseUpstreamScheduler):
    """This Scheduler will handle changes on a variety of branches. It will
    accumulate Changes for each branch separately. It works by creating a
    separate Scheduler for each new branch it sees."""

    schedulerFactory = Scheduler
    fileIsImportant = None

    compare_attrs = ('name', 'branches', 'treeStableTimer', 'builderNames',
                     'fileIsImportant', 'properties')

    def __init__(self, name, branches, treeStableTimer, builderNames,
                 fileIsImportant=None, properties={}):
        """
        @param name: the name of this Scheduler
        @param branches: The branch names that the Scheduler should pay
                         attention to. Any Change that is not on one of these
                         branches will be ignored. It can be set to None to
                         accept changes from any branch. Don't use [] (an
                         empty list), because that means we don't pay
                         attention to *any* branches, so we'll never build
                         anything.
        @param treeStableTimer: the duration, in seconds, for which the tree
                                must remain unchanged before a build will be
                                triggered. This is intended to avoid builds
                                of partially-committed fixes.
        @param builderNames: a list of Builder names. When this Scheduler
                             decides to start a set of builds, they will be
                             run on the Builders named by this list.

        @param fileIsImportant: A callable which takes one argument (a Change
                                instance) and returns True if the change is
                                worth building, and False if it is not.
                                Unimportant Changes are accumulated until the
                                build is triggered by an important change.
                                The default value of None means that all
                                Changes are important.

        @param properties: properties to apply to all builds started from this 
                           scheduler
        """

        BaseUpstreamScheduler.__init__(self, name, properties)
        self.treeStableTimer = treeStableTimer
        for b in builderNames:
            assert isinstance(b, str)
        self.builderNames = builderNames
        self.branches = branches
        if self.branches == []:
            log.msg("AnyBranchScheduler %s: branches=[], so we will ignore "
                    "all branches, and never trigger any builds. Please set "
                    "branches=None to mean 'all branches'" % self)
            # consider raising an exception here, to make this warning more
            # prominent, but I can vaguely imagine situations where you might
            # want to comment out branches temporarily and wouldn't
            # appreciate it being treated as an error.
        if fileIsImportant:
            assert callable(fileIsImportant)
            self.fileIsImportant = fileIsImportant
        self.schedulers = {} # one per branch

    def __repr__(self):
        return "<AnyBranchScheduler '%s'>" % self.name

    def listBuilderNames(self):
        return self.builderNames

    def getPendingBuildTimes(self):
        bts = []
        for s in self.schedulers.values():
            if s.nextBuildTime is not None:
                bts.append(s.nextBuildTime)
        return bts

    def buildSetFinished(self, bss):
        # we don't care if a build has finished; one of the per-branch builders
        # will take care of it, instead.
        pass

    def addChange(self, change):
        branch = change.branch
        if self.branches is not None and branch not in self.branches:
            log.msg("%s ignoring off-branch %s" % (self, change))
            return
        s = self.schedulers.get(branch)
        if not s:
            if branch:
                name = self.name + "." + branch
            else:
                name = self.name + ".<default>"
            s = self.schedulerFactory(name, branch,
                                      self.treeStableTimer,
                                      self.builderNames,
                                      self.fileIsImportant)
            s.successWatchers = self.successWatchers
            s.setServiceParent(self)
            s.properties = self.properties
            # TODO: does this result in schedulers that stack up forever?
            # When I make the persistify-pass, think about this some more.
            self.schedulers[branch] = s
        s.addChange(change)


class Dependent(BaseUpstreamScheduler):
    """This scheduler runs some set of 'downstream' builds when the
    'upstream' scheduler has completed successfully."""
    implements(interfaces.IDownstreamScheduler)

    compare_attrs = ('name', 'upstream', 'builderNames', 'properties')

    def __init__(self, name, upstream, builderNames, properties={}):
        assert interfaces.IUpstreamScheduler.providedBy(upstream)
        BaseUpstreamScheduler.__init__(self, name, properties)
        self.upstream = upstream
        self.builderNames = builderNames

    def listBuilderNames(self):
        return self.builderNames

    def getPendingBuildTimes(self):
        # report the upstream's value
        return self.upstream.getPendingBuildTimes()

    def startService(self):
        service.MultiService.startService(self)
        self.upstream.subscribeToSuccessfulBuilds(self.upstreamBuilt)

    def stopService(self):
        d = service.MultiService.stopService(self)
        self.upstream.unsubscribeToSuccessfulBuilds(self.upstreamBuilt)
        return d

    def upstreamBuilt(self, ss):
        bs = buildset.BuildSet(self.builderNames, ss,
                    properties=self.properties)
        self.submitBuildSet(bs)

    def checkUpstreamScheduler(self):
        # find our *active* upstream scheduler (which may not be self.upstream!) by name
        up_name = self.upstream.name
        upstream = None
        for s in self.parent.allSchedulers():
            if s.name == up_name and interfaces.IUpstreamScheduler.providedBy(s):
                upstream = s
        if not upstream:
            log.msg("ERROR: Couldn't find upstream scheduler of name <%s>" %
                up_name)

        # if it's already correct, we're good to go
        if upstream is self.upstream:
            return

        # otherwise, associate with the new upstream.  We also keep listening
        # to the old upstream, in case it's in the middle of a build
        upstream.subscribeToSuccessfulBuilds(self.upstreamBuilt)
        self.upstream = upstream
        log.msg("Dependent <%s> connected to new Upstream <%s>" %
                (self.name, up_name))

class Periodic(BaseUpstreamScheduler):
    """Instead of watching for Changes, this Scheduler can just start a build
    at fixed intervals. The C{periodicBuildTimer} parameter sets the number
    of seconds to wait between such periodic builds. The first build will be
    run immediately."""

    # TODO: consider having this watch another (changed-based) scheduler and
    # merely enforce a minimum time between builds.

    compare_attrs = ('name', 'builderNames', 'periodicBuildTimer', 'branch', 'properties')

    def __init__(self, name, builderNames, periodicBuildTimer,
                 branch=None, properties={}):
        BaseUpstreamScheduler.__init__(self, name, properties)
        self.builderNames = builderNames
        self.periodicBuildTimer = periodicBuildTimer
        self.branch = branch
        self.reason = ("The Periodic scheduler named '%s' triggered this build"
                       % name)
        self.timer = internet.TimerService(self.periodicBuildTimer,
                                           self.doPeriodicBuild)
        self.timer.setServiceParent(self)

    def listBuilderNames(self):
        return self.builderNames

    def getPendingBuildTimes(self):
        # TODO: figure out when self.timer is going to fire next and report
        # that
        return []

    def doPeriodicBuild(self):
        bs = buildset.BuildSet(self.builderNames,
                               SourceStamp(branch=self.branch),
                               self.reason,
                               properties=self.properties)
        self.submitBuildSet(bs)



class Nightly(BaseUpstreamScheduler):
    """Imitate 'cron' scheduling. This can be used to schedule a nightly
    build, or one which runs are certain times of the day, week, or month.

    Pass some subset of minute, hour, dayOfMonth, month, and dayOfWeek; each
    may be a single number or a list of valid values. The builds will be
    triggered whenever the current time matches these values. Wildcards are
    represented by a '*' string. All fields default to a wildcard except
    'minute', so with no fields this defaults to a build every hour, on the
    hour.

    For example, the following master.cfg clause will cause a build to be
    started every night at 3:00am::

     s = Nightly('nightly', ['builder1', 'builder2'], hour=3, minute=0)
     c['schedules'].append(s)

    This scheduler will perform a build each monday morning at 6:23am and
    again at 8:23am::

     s = Nightly('BeforeWork', ['builder1'],
                 dayOfWeek=0, hour=[6,8], minute=23)

    The following runs a build every two hours::

     s = Nightly('every2hours', ['builder1'], hour=range(0, 24, 2))

    And this one will run only on December 24th::

     s = Nightly('SleighPreflightCheck', ['flying_circuits', 'radar'],
                 month=12, dayOfMonth=24, hour=12, minute=0)

    For dayOfWeek and dayOfMonth, builds are triggered if the date matches
    either of them. All time values are compared against the tuple returned
    by time.localtime(), so month and dayOfMonth numbers start at 1, not
    zero. dayOfWeek=0 is Monday, dayOfWeek=6 is Sunday.

    onlyIfChanged functionality
    s = Nightly('nightly', ['builder1', 'builder2'],
                hour=3, minute=0, onlyIfChanged=True)
    When the flag is True (False by default), the build is trigged if
    the date matches and if the branch has changed

    fileIsImportant parameter is implemented as defined in class Scheduler
    """

    compare_attrs = ('name', 'builderNames',
                     'minute', 'hour', 'dayOfMonth', 'month',
                     'dayOfWeek', 'branch', 'onlyIfChanged',
                     'fileIsImportant', 'properties')

    def __init__(self, name, builderNames, minute=0, hour='*',
                 dayOfMonth='*', month='*', dayOfWeek='*',
                 branch=None, fileIsImportant=None, onlyIfChanged=False, properties={}):
        # Setting minute=0 really makes this an 'Hourly' scheduler. This
        # seemed like a better default than minute='*', which would result in
        # a build every 60 seconds.
        BaseUpstreamScheduler.__init__(self, name, properties)
        self.builderNames = builderNames
        self.minute = minute
        self.hour = hour
        self.dayOfMonth = dayOfMonth
        self.month = month
        self.dayOfWeek = dayOfWeek
        self.branch = branch
        self.onlyIfChanged = onlyIfChanged
        self.delayedRun = None
        self.nextRunTime = None
        self.reason = ("The Nightly scheduler named '%s' triggered this build"
                       % name)

        self.importantChanges   = [] 
        self.unimportantChanges = [] 
        self.fileIsImportant    = None 
        if fileIsImportant: 
            assert callable(fileIsImportant) 
            self.fileIsImportant = fileIsImportant 

    def addTime(self, timetuple, secs):
        return time.localtime(time.mktime(timetuple)+secs)
    def findFirstValueAtLeast(self, values, value, default=None):
        for v in values:
            if v >= value: return v
        return default

    def setTimer(self):
        self.nextRunTime = self.calculateNextRunTime()
        self.delayedRun = reactor.callLater(self.nextRunTime - time.time(),
                                            self.doPeriodicBuild)

    def startService(self):
        BaseUpstreamScheduler.startService(self)
        self.setTimer()

    def stopService(self):
        BaseUpstreamScheduler.stopService(self)
        self.delayedRun.cancel()

    def isRunTime(self, timetuple):
        def check(ourvalue, value):
            if ourvalue == '*': return True
            if isinstance(ourvalue, int): return value == ourvalue
            return (value in ourvalue)

        if not check(self.minute, timetuple[4]):
            #print 'bad minute', timetuple[4], self.minute
            return False

        if not check(self.hour, timetuple[3]):
            #print 'bad hour', timetuple[3], self.hour
            return False

        if not check(self.month, timetuple[1]):
            #print 'bad month', timetuple[1], self.month
            return False

        if self.dayOfMonth != '*' and self.dayOfWeek != '*':
            # They specified both day(s) of month AND day(s) of week.
            # This means that we only have to match one of the two. If
            # neither one matches, this time is not the right time.
            if not (check(self.dayOfMonth, timetuple[2]) or
                    check(self.dayOfWeek, timetuple[6])):
                #print 'bad day'
                return False
        else:
            if not check(self.dayOfMonth, timetuple[2]):
                #print 'bad day of month'
                return False

            if not check(self.dayOfWeek, timetuple[6]):
                #print 'bad day of week'
                return False

        return True

    def calculateNextRunTime(self):
        return self.calculateNextRunTimeFrom(time.time())

    def calculateNextRunTimeFrom(self, now):
        dateTime = time.localtime(now)

        # Remove seconds by advancing to at least the next minue
        dateTime = self.addTime(dateTime, 60-dateTime[5])

        # Now we just keep adding minutes until we find something that matches

        # It not an efficient algorithm, but it'll *work* for now
        yearLimit = dateTime[0]+2
        while not self.isRunTime(dateTime):
            dateTime = self.addTime(dateTime, 60)
            #print 'Trying', time.asctime(dateTime)
            assert dateTime[0] < yearLimit, 'Something is wrong with this code'
        return time.mktime(dateTime)

    def listBuilderNames(self):
        return self.builderNames

    def getPendingBuildTimes(self):
        # TODO: figure out when self.timer is going to fire next and report
        # that
        if self.nextRunTime is None: return []
        return [self.nextRunTime]

    def doPeriodicBuild(self):
        # Schedule the next run
        self.setTimer()

        if  self.onlyIfChanged:
            if len(self.importantChanges) > 0: 
                changes = self.importantChanges + self.unimportantChanges 
                # And trigger a build 
                log.msg("Nightly Scheduler <%s>: triggering build" % self.name) 
                bs = buildset.BuildSet(self.builderNames,
                                       SourceStamp(changes=changes),
                                       self.reason,
                                       properties=self.properties)
                self.submitBuildSet(bs)
                # Reset the change lists 
                self.importantChanges = [] 
                self.unimportantChanges = []
            else: 
                log.msg("Nightly Scheduler <%s>: skipping build - No important change" % self.name)
        else:
            # And trigger a build
            bs = buildset.BuildSet(self.builderNames,
                                   SourceStamp(branch=self.branch),
                                   self.reason,
                                   properties=self.properties)
            self.submitBuildSet(bs) 

    def addChange(self, change):
        if  self.onlyIfChanged:
            if change.branch != self.branch: 
                log.msg("Nightly Scheduler <%s>: ignoring change %d on off-branch %s" % (self.name, change.revision, change.branch)) 
                return 
            if not self.fileIsImportant:
                self.addImportantChange(change) 
            elif self.fileIsImportant(change): 
                self.addImportantChange(change) 
            else: 
                self.addUnimportantChange(change)
        else:
            log.msg("Nightly Scheduler <%s>: no add change" % self.name)
            pass
 
    def addImportantChange(self, change):
        log.msg("Nightly Scheduler <%s>: change %s from %s is important, adding it" % (self.name, change.revision, change.who)) 
        self.importantChanges.append(change) 
 
    def addUnimportantChange(self, change):
        log.msg("Nightly Scheduler <%s>: change %s from %s is not important, adding it" % (self.name, change.revision, change.who)) 
        self.unimportantChanges.append(change) 


class TryBase(BaseScheduler):
    def __init__(self, name, builderNames, properties={}):
        BaseScheduler.__init__(self, name, properties)
        self.builderNames = builderNames

    def listBuilderNames(self):
        return self.builderNames

    def getPendingBuildTimes(self):
        # we can't predict what the developers are going to do in the future
        return []

    def addChange(self, change):
        # Try schedulers ignore Changes
        pass

    def processBuilderList(self, builderNames):
        # self.builderNames is the configured list of builders
        # available for try.  If the user supplies a list of builders,
        # it must be restricted to the configured list.  If not, build
        # on all of the configured builders.
        if builderNames:
            for b in builderNames:
                if not b in self.builderNames:
                    log.msg("%s got with builder %s" % (self, b))
                    log.msg(" but that wasn't in our list: %s"
                            % (self.builderNames,))
                    return []
        else:
            builderNames = self.builderNames
        return builderNames

class BadJobfile(Exception):
    pass

class JobFileScanner(basic.NetstringReceiver):
    def __init__(self):
        self.strings = []
        self.transport = self # so transport.loseConnection works
        self.error = False

    def stringReceived(self, s):
        self.strings.append(s)

    def loseConnection(self):
        self.error = True

class Try_Jobdir(TryBase):
    compare_attrs = ( 'name', 'builderNames', 'jobdir', 'properties' )

    def __init__(self, name, builderNames, jobdir, properties={}):
        TryBase.__init__(self, name, builderNames, properties)
        self.jobdir = jobdir
        self.watcher = MaildirService()
        self.watcher.setServiceParent(self)

    def setServiceParent(self, parent):
        self.watcher.setBasedir(os.path.join(parent.basedir, self.jobdir))
        TryBase.setServiceParent(self, parent)

    def parseJob(self, f):
        # jobfiles are serialized build requests. Each is a list of
        # serialized netstrings, in the following order:
        #  "1", the version number of this format
        #  buildsetID, arbitrary string, used to find the buildSet later
        #  branch name, "" for default-branch
        #  base revision, "" for HEAD
        #  patchlevel, usually "1"
        #  patch
        #  builderNames...
        p = JobFileScanner()
        p.dataReceived(f.read())
        if p.error:
            raise BadJobfile("unable to parse netstrings")
        s = p.strings
        ver = s.pop(0)
        if ver != "1":
            raise BadJobfile("unknown version '%s'" % ver)
        buildsetID, branch, baserev, patchlevel, diff = s[:5]
        builderNames = s[5:]
        if branch == "":
            branch = None
        if baserev == "":
            baserev = None
        patchlevel = int(patchlevel)
        patch = (patchlevel, diff)
        ss = SourceStamp(branch, baserev, patch)
        return builderNames, ss, buildsetID

    def messageReceived(self, filename):
        md = os.path.join(self.parent.basedir, self.jobdir)
        if runtime.platformType == "posix":
            # open the file before moving it, because I'm afraid that once
            # it's in cur/, someone might delete it at any moment
            path = os.path.join(md, "new", filename)
            f = open(path, "r")
            os.rename(os.path.join(md, "new", filename),
                      os.path.join(md, "cur", filename))
        else:
            # do this backwards under windows, because you can't move a file
            # that somebody is holding open. This was causing a Permission
            # Denied error on bear's win32-twisted1.3 buildslave.
            os.rename(os.path.join(md, "new", filename),
                      os.path.join(md, "cur", filename))
            path = os.path.join(md, "cur", filename)
            f = open(path, "r")

        try:
            builderNames, ss, bsid = self.parseJob(f)
        except BadJobfile:
            log.msg("%s reports a bad jobfile in %s" % (self, filename))
            log.err()
            return
        # Validate/fixup the builder names.
        builderNames = self.processBuilderList(builderNames)
        if not builderNames:
            return
        reason = "'try' job"
        bs = buildset.BuildSet(builderNames, ss, reason=reason, 
                    bsid=bsid, properties=self.properties)
        self.submitBuildSet(bs)

class Try_Userpass(TryBase):
    compare_attrs = ( 'name', 'builderNames', 'port', 'userpass', 'properties' )
    implements(portal.IRealm)

    def __init__(self, name, builderNames, port, userpass, properties={}):
        TryBase.__init__(self, name, builderNames, properties)
        if type(port) is int:
            port = "tcp:%d" % port
        self.port = port
        self.userpass = userpass
        c = checkers.InMemoryUsernamePasswordDatabaseDontUse()
        for user,passwd in self.userpass:
            c.addUser(user, passwd)

        p = portal.Portal(self)
        p.registerChecker(c)
        f = pb.PBServerFactory(p)
        s = strports.service(port, f)
        s.setServiceParent(self)

    def getPort(self):
        # utility method for tests: figure out which TCP port we just opened.
        return self.services[0]._port.getHost().port

    def requestAvatar(self, avatarID, mind, interface):
        log.msg("%s got connection from user %s" % (self, avatarID))
        assert interface == pb.IPerspective
        p = Try_Userpass_Perspective(self, avatarID)
        return (pb.IPerspective, p, lambda: None)

class Try_Userpass_Perspective(pbutil.NewCredPerspective):
    def __init__(self, parent, username):
        self.parent = parent
        self.username = username

    def perspective_try(self, branch, revision, patch, builderNames, properties={}):
        log.msg("user %s requesting build on builders %s" % (self.username,
                                                             builderNames))
        # Validate/fixup the builder names.
        builderNames = self.parent.processBuilderList(builderNames)
        if not builderNames:
            return
        ss = SourceStamp(branch, revision, patch)
        reason = "'try' job from user %s" % self.username

        # roll the specified props in with our inherited props
        combined_props = Properties()
        combined_props.updateFromProperties(self.parent.properties)
        combined_props.update(properties, "try build")

        bs = buildset.BuildSet(builderNames, 
                               ss,
                               reason=reason, 
                               properties=combined_props)

        self.parent.submitBuildSet(bs)

        # return a remotely-usable BuildSetStatus object
        from buildbot.status.client import makeRemote
        return makeRemote(bs.status)

class Triggerable(BaseUpstreamScheduler):
    """This scheduler doesn't do anything until it is triggered by a Trigger
    step in a factory. In general, that step will not complete until all of
    the builds that I fire have finished.
    """

    compare_attrs = ('name', 'builderNames', 'properties')

    def __init__(self, name, builderNames, properties={}):
        BaseUpstreamScheduler.__init__(self, name, properties)
        self.builderNames = builderNames

    def listBuilderNames(self):
        return self.builderNames

    def getPendingBuildTimes(self):
        return []

    def trigger(self, ss, set_props=None):
        """Trigger this scheduler. Returns a deferred that will fire when the
        buildset is finished.
        """

        # properties for this buildset are composed of our own properties,
        # potentially overridden by anything from the triggering build
        props = Properties()
        props.updateFromProperties(self.properties)
        if set_props: props.updateFromProperties(set_props)

        bs = buildset.BuildSet(self.builderNames, ss, properties=props)
        d = bs.waitUntilFinished()
        self.submitBuildSet(bs)
        return d