test_buildslave_libvirt.py

# This file is part of Buildbot.  Buildbot is free software: you can
# redistribute it and/or modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation, version 2.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 51
# Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# Copyright Buildbot Team Members

import mock

from buildbot import config
from buildbot.buildslave import libvirt as libvirtbuildslave
from buildbot.test.fake import libvirt
from twisted.internet import defer
from twisted.internet import reactor
from twisted.internet import utils
from twisted.python import failure
from twisted.trial import unittest


class TestLibVirtSlave(unittest.TestCase):

    class ConcreteBuildSlave(libvirtbuildslave.LibVirtSlave):
        pass

    def setUp(self):
        self.patch(libvirtbuildslave, "libvirt", libvirt)
        self.conn = libvirtbuildslave.Connection("test://")
        self.lvconn = self.conn.connection

    def test_constructor_nolibvirt(self):
        self.patch(libvirtbuildslave, "libvirt", None)
        self.assertRaises(config.ConfigErrors, self.ConcreteBuildSlave,
                          'bot', 'pass', None, 'path', 'path')

    @defer.inlineCallbacks
    def test_constructor_minimal(self):
        bs = self.ConcreteBuildSlave('bot', 'pass', self.conn, 'path', 'otherpath')
        yield bs._find_existing_deferred
        self.assertEqual(bs.slavename, 'bot')
        self.assertEqual(bs.password, 'pass')
        self.assertEqual(bs.connection, self.conn)
        self.assertEqual(bs.image, 'path')
        self.assertEqual(bs.base_image, 'otherpath')
        # XXX(sa2ajj): interesting test, this probably needs to be an external constant
        self.assertEqual(bs.missing_timeout, 10 * 60)

    @defer.inlineCallbacks
    def test_find_existing(self):
        d = self.lvconn.fake_add("bot")

        bs = self.ConcreteBuildSlave('bot', 'pass', self.conn, 'p', 'o')
        yield bs._find_existing_deferred

        self.assertEqual(bs.domain.domain, d)
        self.assertEqual(bs.substantiated, True)

    @defer.inlineCallbacks
    def test_prepare_base_image_none(self):
        self.patch(utils, "getProcessValue", mock.Mock())
        utils.getProcessValue.side_effect = lambda x, y: defer.succeed(0)

        bs = self.ConcreteBuildSlave('bot', 'pass', self.conn, 'p', None)
        yield bs._find_existing_deferred
        yield bs._prepare_base_image()

        self.assertEqual(utils.getProcessValue.call_count, 0)

    @defer.inlineCallbacks
    def test_prepare_base_image_cheap(self):
        self.patch(utils, "getProcessValue", mock.Mock())
        utils.getProcessValue.side_effect = lambda x, y: defer.succeed(0)

        bs = self.ConcreteBuildSlave('bot', 'pass', self.conn, 'p', 'o')
        yield bs._find_existing_deferred
        yield bs._prepare_base_image()

        utils.getProcessValue.assert_called_with(
            "qemu-img", ["create", "-b", "o", "-f", "qcow2", "p"])

    @defer.inlineCallbacks
    def test_prepare_base_image_full(self):
        pass
        self.patch(utils, "getProcessValue", mock.Mock())
        utils.getProcessValue.side_effect = lambda x, y: defer.succeed(0)

        bs = self.ConcreteBuildSlave('bot', 'pass', self.conn, 'p', 'o')
        yield bs._find_existing_deferred
        bs.cheap_copy = False
        yield bs._prepare_base_image()

        utils.getProcessValue.assert_called_with(
            "cp", ["o", "p"])

    @defer.inlineCallbacks
    def test_start_instance(self):
        bs = self.ConcreteBuildSlave('b', 'p', self.conn, 'p', 'o',
                                     xml='<xml/>')

        prep = mock.Mock()
        prep.side_effect = lambda: defer.succeed(0)
        self.patch(bs, "_prepare_base_image", prep)

        yield bs._find_existing_deferred
        started = yield bs.start_instance(mock.Mock())

        self.assertEqual(started, True)

    @defer.inlineCallbacks
    def test_start_instance_create_fails(self):
        bs = self.ConcreteBuildSlave('b', 'p', self.conn, 'p', 'o',
                                     xml='<xml/>')

        prep = mock.Mock()
        prep.side_effect = lambda: defer.succeed(0)
        self.patch(bs, "_prepare_base_image", prep)

        create = mock.Mock()
        create.side_effect = lambda self: defer.fail(
            failure.Failure(RuntimeError('oh noes')))
        self.patch(libvirtbuildslave.Connection, 'create', create)

        yield bs._find_existing_deferred
        started = yield bs.start_instance(mock.Mock())

        self.assertEqual(bs.domain, None)
        self.assertEqual(started, False)
        self.assertEqual(len(self.flushLoggedErrors(RuntimeError)), 1)

    @defer.inlineCallbacks
    def setup_canStartBuild(self):
        bs = self.ConcreteBuildSlave('b', 'p', self.conn, 'p', 'o')
        yield bs._find_existing_deferred
        bs.updateLocks()
        defer.returnValue(bs)

    @defer.inlineCallbacks
    def test_canStartBuild(self):
        bs = yield self.setup_canStartBuild()
        self.assertEqual(bs.canStartBuild(), True)

    @defer.inlineCallbacks
    def test_canStartBuild_notready(self):
        """
        If a LibVirtSlave hasnt finished scanning for existing VMs then we shouldn't
        start builds on it as it might create a 2nd VM when we want to reuse the existing
        one.
        """
        bs = yield self.setup_canStartBuild()
        bs.ready = False
        self.assertEqual(bs.canStartBuild(), False)

    @defer.inlineCallbacks
    def test_canStartBuild_domain_and_not_connected(self):
        """
        If we've found that the VM this slave would instance already exists but hasnt
        connected then we shouldn't start builds or we'll end up with a dupe.
        """
        bs = yield self.setup_canStartBuild()
        bs.domain = mock.Mock()
        self.assertEqual(bs.canStartBuild(), False)

    @defer.inlineCallbacks
    def test_canStartBuild_domain_and_connected(self):
        """
        If we've found an existing VM and it is connected then we should start builds
        """
        bs = yield self.setup_canStartBuild()
        bs.domain = mock.Mock()
        isconnected = mock.Mock()
        isconnected.return_value = True
        self.patch(bs, "isConnected", isconnected)
        self.assertEqual(bs.canStartBuild(), True)


class TestWorkQueue(unittest.TestCase):

    def setUp(self):
        self.queue = libvirtbuildslave.WorkQueue()

    def delayed_success(self):
        def work():
            d = defer.Deferred()
            reactor.callLater(0, d.callback, True)
            return d
        return work

    def delayed_errback(self):
        def work():
            d = defer.Deferred()
            reactor.callLater(0, d.errback,
                              failure.Failure(RuntimeError("Test failure")))
            return d
        return work

    def expect_errback(self, d):
        @d.addCallback
        def shouldnt_get_called(f):
            self.failUnlessEqual(True, False)

        @d.addErrback
        def errback(f):
            # log.msg("errback called?")
            pass
        return d

    def test_handle_exceptions(self):
        def work():
            raise ValueError
        return self.expect_errback(self.queue.execute(work))

    def test_handle_immediate_errback(self):
        def work():
            return defer.fail(RuntimeError("Sad times"))
        return self.expect_errback(self.queue.execute(work))

    def test_handle_delayed_errback(self):
        work = self.delayed_errback()
        return self.expect_errback(self.queue.execute(work))

    def test_handle_immediate_success(self):
        def work():
            return defer.succeed(True)
        return self.queue.execute(work)

    def test_handle_delayed_success(self):
        work = self.delayed_success()
        return self.queue.execute(work)

    def test_single_pow_fires(self):
        return self.queue.execute(self.delayed_success())

    def test_single_pow_errors_gracefully(self):
        d = self.queue.execute(self.delayed_errback())
        return self.expect_errback(d)

    def test_fail_doesnt_break_further_work(self):
        self.expect_errback(self.queue.execute(self.delayed_errback()))
        return self.queue.execute(self.delayed_success())

    def test_second_pow_fires(self):
        self.queue.execute(self.delayed_success())
        return self.queue.execute(self.delayed_success())

    def test_work(self):
        # We want these deferreds to fire in order
        flags = {1: False, 2: False, 3: False}

        # When first deferred fires, flags[2] and flags[3] should still be false
        # flags[1] shouldnt already be set, either
        d1 = self.queue.execute(self.delayed_success())

        @d1.addCallback
        def cb1(res):
            self.failUnlessEqual(flags[1], False)
            flags[1] = True
            self.failUnlessEqual(flags[2], False)
            self.failUnlessEqual(flags[3], False)

        # When second deferred fires, only flags[3] should be set
        # flags[2] should definitely be False
        d2 = self.queue.execute(self.delayed_success())

        @d2.addCallback
        def cb2(res):
            assert flags[2] == False
            flags[2] = True
            assert flags[1]
            assert flags[3] == False

        # When third deferred fires, only flags[3] should be unset
        d3 = self.queue.execute(self.delayed_success())

        @d3.addCallback
        def cb3(res):
            assert flags[3] == False
            flags[3] = True
            assert flags[1]
            assert flags[2]

        return defer.DeferredList([d1, d2, d3], fireOnOneErrback=True)