github.com/mwhudson/juju@v0.0.0-20160512215208-90ff01f3497f/cmd/jujud/agent/machine_test.go

// Copyright 2012-2016 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.

package agent

import (
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"reflect"
	"runtime"
	"strings"
	"sync"
	"time"

	"github.com/juju/cmd"
	"github.com/juju/cmd/cmdtesting"
	"github.com/juju/errors"
	"github.com/juju/names"
	gitjujutesting "github.com/juju/testing"
	jc "github.com/juju/testing/checkers"
	"github.com/juju/utils"
	"github.com/juju/utils/arch"
	"github.com/juju/utils/series"
	"github.com/juju/utils/set"
	"github.com/juju/utils/ssh"
	sshtesting "github.com/juju/utils/ssh/testing"
	"github.com/juju/utils/symlink"
	"github.com/juju/version"
	gc "gopkg.in/check.v1"
	"gopkg.in/juju/charm.v6-unstable"
	"gopkg.in/juju/charmrepo.v2-unstable"
	"gopkg.in/natefinch/lumberjack.v2"

	"github.com/juju/juju/agent"
	"github.com/juju/juju/api"
	apideployer "github.com/juju/juju/api/deployer"
	"github.com/juju/juju/api/imagemetadata"
	apimachiner "github.com/juju/juju/api/machiner"
	charmtesting "github.com/juju/juju/apiserver/charmrevisionupdater/testing"
	"github.com/juju/juju/apiserver/params"
	"github.com/juju/juju/cert"
	agenttesting "github.com/juju/juju/cmd/jujud/agent/testing"
	cmdutil "github.com/juju/juju/cmd/jujud/util"
	lxctesting "github.com/juju/juju/container/lxc/testing"
	envtesting "github.com/juju/juju/environs/testing"
	"github.com/juju/juju/feature"
	"github.com/juju/juju/instance"
	"github.com/juju/juju/juju"
	jujutesting "github.com/juju/juju/juju/testing"
	"github.com/juju/juju/mongo"
	"github.com/juju/juju/mongo/mongotest"
	"github.com/juju/juju/network"
	"github.com/juju/juju/provider/dummy"
	"github.com/juju/juju/service/upstart"
	"github.com/juju/juju/state"
	"github.com/juju/juju/state/watcher"
	"github.com/juju/juju/status"
	"github.com/juju/juju/storage"
	coretesting "github.com/juju/juju/testing"
	"github.com/juju/juju/tools"
	jujuversion "github.com/juju/juju/version"
	"github.com/juju/juju/worker"
	"github.com/juju/juju/worker/authenticationworker"
	"github.com/juju/juju/worker/certupdater"
	"github.com/juju/juju/worker/deployer"
	"github.com/juju/juju/worker/diskmanager"
	"github.com/juju/juju/worker/instancepoller"
	"github.com/juju/juju/worker/logsender"
	"github.com/juju/juju/worker/machiner"
	"github.com/juju/juju/worker/mongoupgrader"
	"github.com/juju/juju/worker/peergrouper"
	"github.com/juju/juju/worker/resumer"
	"github.com/juju/juju/worker/singular"
	"github.com/juju/juju/worker/storageprovisioner"
	"github.com/juju/juju/worker/upgrader"
)

var (
	_ = gc.Suite(&MachineSuite{})
	_ = gc.Suite(&MachineWithCharmsSuite{})
	_ = gc.Suite(&mongoSuite{})
)

type commonMachineSuite struct {
	singularRecord *singularRunnerRecord
	lxctesting.TestSuite
	fakeEnsureMongo *agenttesting.FakeEnsureMongo
	AgentSuite
}

func (s *commonMachineSuite) SetUpSuite(c *gc.C) {
	s.AgentSuite.SetUpSuite(c)
	s.TestSuite.SetUpSuite(c)
	s.AgentSuite.PatchValue(&jujuversion.Current, coretesting.FakeVersionNumber)
	s.AgentSuite.PatchValue(&stateWorkerDialOpts, mongotest.DialOpts())
}

func (s *commonMachineSuite) TearDownSuite(c *gc.C) {
	s.TestSuite.TearDownSuite(c)
	s.AgentSuite.TearDownSuite(c)
}

func (s *commonMachineSuite) SetUpTest(c *gc.C) {
	s.AgentSuite.SetUpTest(c)
	s.TestSuite.SetUpTest(c)
	s.AgentSuite.PatchValue(&charmrepo.CacheDir, c.MkDir())

	// Patch ssh user to avoid touching ~ubuntu/.ssh/authorized_keys.
	s.AgentSuite.PatchValue(&authenticationworker.SSHUser, "")

	testpath := c.MkDir()
	s.AgentSuite.PatchEnvPathPrepend(testpath)
	// mock out the start method so we can fake install services without sudo
	fakeCmd(filepath.Join(testpath, "start"))
	fakeCmd(filepath.Join(testpath, "stop"))

	s.AgentSuite.PatchValue(&upstart.InitDir, c.MkDir())

	s.singularRecord = newSingularRunnerRecord()
	s.AgentSuite.PatchValue(&newSingularRunner, s.singularRecord.newSingularRunner)
	s.AgentSuite.PatchValue(&peergrouperNew, func(st *state.State) (worker.Worker, error) {
		return newDummyWorker(), nil
	})

	s.fakeEnsureMongo = agenttesting.InstallFakeEnsureMongo(s)
}

func (s *commonMachineSuite) assertChannelActive(c *gc.C, aChannel chan struct{}, intent string) {
	// Wait for channel to be active.
	select {
	case <-aChannel:
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timeout while waiting for %v", intent)
	}
}

func (s *commonMachineSuite) assertChannelInactive(c *gc.C, aChannel chan struct{}, intent string) {
	// Now make sure the channel is not active.
	select {
	case <-aChannel:
		c.Fatalf("%v unexpectedly", intent)
	case <-time.After(startWorkerWait):
	}
}

func fakeCmd(path string) {
	err := ioutil.WriteFile(path, []byte("#!/bin/bash --norc\nexit 0"), 0755)
	if err != nil {
		panic(err)
	}
}

func (s *commonMachineSuite) TearDownTest(c *gc.C) {
	s.TestSuite.TearDownTest(c)
	s.AgentSuite.TearDownTest(c)
}

// primeAgent adds a new Machine to run the given jobs, and sets up the
// machine agent's directory.  It returns the new machine, the
// agent's configuration and the tools currently running.
func (s *commonMachineSuite) primeAgent(c *gc.C, jobs ...state.MachineJob) (m *state.Machine, agentConfig agent.ConfigSetterWriter, tools *tools.Tools) {
	vers := version.Binary{
		Number: jujuversion.Current,
		Arch:   arch.HostArch(),
		Series: series.HostSeries(),
	}
	return s.primeAgentVersion(c, vers, jobs...)
}

// primeAgentVersion is similar to primeAgent, but permits the
// caller to specify the version.Binary to prime with.
func (s *commonMachineSuite) primeAgentVersion(c *gc.C, vers version.Binary, jobs ...state.MachineJob) (m *state.Machine, agentConfig agent.ConfigSetterWriter, tools *tools.Tools) {
	m, err := s.State.AddMachine("quantal", jobs...)
	c.Assert(err, jc.ErrorIsNil)
	return s.primeAgentWithMachine(c, m, vers)
}

func (s *commonMachineSuite) primeAgentWithMachine(c *gc.C, m *state.Machine, vers version.Binary) (*state.Machine, agent.ConfigSetterWriter, *tools.Tools) {
	pinger, err := m.SetAgentPresence()
	c.Assert(err, jc.ErrorIsNil)
	s.AddCleanup(func(c *gc.C) {
		err := pinger.Stop()
		c.Check(err, jc.ErrorIsNil)
	})
	return s.configureMachine(c, m.Id(), vers)
}

func (s *commonMachineSuite) configureMachine(c *gc.C, machineId string, vers version.Binary) (
	machine *state.Machine, agentConfig agent.ConfigSetterWriter, tools *tools.Tools,
) {
	m, err := s.State.Machine(machineId)
	c.Assert(err, jc.ErrorIsNil)

	// Add a machine and ensure it is provisioned.
	inst, md := jujutesting.AssertStartInstance(c, s.Environ, machineId)
	c.Assert(m.SetProvisioned(inst.Id(), agent.BootstrapNonce, md), jc.ErrorIsNil)

	// Add an address for the tests in case the initiateMongoServer
	// codepath is exercised.
	s.setFakeMachineAddresses(c, m)

	// Set up the new machine.
	err = m.SetAgentVersion(vers)
	c.Assert(err, jc.ErrorIsNil)
	err = m.SetPassword(initialMachinePassword)
	c.Assert(err, jc.ErrorIsNil)
	tag := m.Tag()
	if m.IsManager() {
		err = m.SetMongoPassword(initialMachinePassword)
		c.Assert(err, jc.ErrorIsNil)
		agentConfig, tools = s.PrimeStateAgentVersion(c, tag, initialMachinePassword, vers)
		info, ok := agentConfig.StateServingInfo()
		c.Assert(ok, jc.IsTrue)
		ssi := cmdutil.ParamsStateServingInfoToStateStateServingInfo(info)
		err = s.State.SetStateServingInfo(ssi)
		c.Assert(err, jc.ErrorIsNil)
	} else {
		agentConfig, tools = s.PrimeAgentVersion(c, tag, initialMachinePassword, vers)
	}
	err = agentConfig.Write()
	c.Assert(err, jc.ErrorIsNil)
	return m, agentConfig, tools
}

func NewTestMachineAgentFactory(
	agentConfWriter AgentConfigWriter,
	bufferedLogs logsender.LogRecordCh,
	rootDir string,
) func(string) *MachineAgent {
	return func(machineId string) *MachineAgent {
		return NewMachineAgent(
			machineId,
			agentConfWriter,
			bufferedLogs,
			worker.NewRunner(cmdutil.IsFatal, cmdutil.MoreImportant, worker.RestartDelay),
			&mockLoopDeviceManager{},
			rootDir,
		)
	}
}

// newAgent returns a new MachineAgent instance
func (s *commonMachineSuite) newAgent(c *gc.C, m *state.Machine) *MachineAgent {
	agentConf := agentConf{dataDir: s.DataDir()}
	agentConf.ReadConfig(names.NewMachineTag(m.Id()).String())
	machineAgentFactory := NewTestMachineAgentFactory(&agentConf, nil, c.MkDir())
	return machineAgentFactory(m.Id())
}

func (s *MachineSuite) TestParseSuccess(c *gc.C) {
	create := func() (cmd.Command, AgentConf) {
		agentConf := agentConf{dataDir: s.DataDir()}
		a := NewMachineAgentCmd(
			nil,
			NewTestMachineAgentFactory(&agentConf, nil, c.MkDir()),
			&agentConf,
			&agentConf,
		)
		a.(*machineAgentCmd).logToStdErr = true

		return a, &agentConf
	}
	a := CheckAgentCommand(c, create, []string{"--machine-id", "42"})
	c.Assert(a.(*machineAgentCmd).machineId, gc.Equals, "42")
}

type MachineSuite struct {
	commonMachineSuite
}

var perEnvSingularWorkers = []string{
	"cleaner",
	"minunitsworker",
	"addresserworker",
	"environ-provisioner",
	"charm-revision-updater",
	"discoverspaces",
	"instancepoller",
	"firewaller",
	"unitassigner",
}

const initialMachinePassword = "machine-password-1234567890"

func (s *MachineSuite) SetUpTest(c *gc.C) {
	s.commonMachineSuite.SetUpTest(c)
	// Most of these tests normally finish sub-second on a fast machine.
	// If any given test hits a minute, we have almost certainly become
	// wedged, so dump the logs.
	coretesting.DumpTestLogsAfter(time.Minute, c, s)
}

func (s *MachineSuite) TestParseNonsense(c *gc.C) {
	for _, args := range [][]string{
		{},
		{"--machine-id", "-4004"},
	} {
		var agentConf agentConf
		err := ParseAgentCommand(&machineAgentCmd{agentInitializer: &agentConf}, args)
		c.Assert(err, gc.ErrorMatches, "--machine-id option must be set, and expects a non-negative integer")
	}
}

func (s *MachineSuite) TestParseUnknown(c *gc.C) {
	var agentConf agentConf
	a := &machineAgentCmd{agentInitializer: &agentConf}
	err := ParseAgentCommand(a, []string{"--machine-id", "42", "blistering barnacles"})
	c.Assert(err, gc.ErrorMatches, `unrecognized args: \["blistering barnacles"\]`)
}

func (s *MachineSuite) TestRunInvalidMachineId(c *gc.C) {
	c.Skip("agents don't yet distinguish between temporary and permanent errors")
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	err := s.newAgent(c, m).Run(nil)
	c.Assert(err, gc.ErrorMatches, "some error")
}

func (s *MachineSuite) TestUseLumberjack(c *gc.C) {
	ctx := cmdtesting.Context(c)
	agentConf := FakeAgentConfig{}

	a := NewMachineAgentCmd(
		ctx,
		NewTestMachineAgentFactory(&agentConf, nil, c.MkDir()),
		agentConf,
		agentConf,
	)
	// little hack to set the data that Init expects to already be set
	a.(*machineAgentCmd).machineId = "42"

	err := a.Init(nil)
	c.Assert(err, gc.IsNil)

	l, ok := ctx.Stderr.(*lumberjack.Logger)
	c.Assert(ok, jc.IsTrue)
	c.Check(l.MaxAge, gc.Equals, 0)
	c.Check(l.MaxBackups, gc.Equals, 2)
	c.Check(l.Filename, gc.Equals, filepath.FromSlash("/var/log/juju/machine-42.log"))
	c.Check(l.MaxSize, gc.Equals, 300)
}

func (s *MachineSuite) TestDontUseLumberjack(c *gc.C) {
	ctx := cmdtesting.Context(c)
	agentConf := FakeAgentConfig{}

	a := NewMachineAgentCmd(
		ctx,
		NewTestMachineAgentFactory(&agentConf, nil, c.MkDir()),
		agentConf,
		agentConf,
	)
	// little hack to set the data that Init expects to already be set
	a.(*machineAgentCmd).machineId = "42"

	// set the value that normally gets set by the flag parsing
	a.(*machineAgentCmd).logToStdErr = true

	err := a.Init(nil)
	c.Assert(err, gc.IsNil)

	_, ok := ctx.Stderr.(*lumberjack.Logger)
	c.Assert(ok, jc.IsFalse)
}

func (s *MachineSuite) TestRunStop(c *gc.C) {
	m, ac, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	done := make(chan error)
	go func() {
		done <- a.Run(nil)
	}()
	err := a.Stop()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(<-done, jc.ErrorIsNil)
	c.Assert(charmrepo.CacheDir, gc.Equals, filepath.Join(ac.DataDir(), "charmcache"))
}

func (s *MachineSuite) TestWithDeadMachine(c *gc.C) {
	m, ac, _ := s.primeAgent(c, state.JobHostUnits)
	err := m.EnsureDead()
	c.Assert(err, jc.ErrorIsNil)
	a := s.newAgent(c, m)
	err = runWithTimeout(a)
	c.Assert(err, jc.ErrorIsNil)

	_, err = os.Stat(ac.DataDir())
	c.Assert(err, jc.Satisfies, os.IsNotExist)
}

func (s *MachineSuite) TestWithRemovedMachine(c *gc.C) {
	m, ac, _ := s.primeAgent(c, state.JobHostUnits)
	err := m.EnsureDead()
	c.Assert(err, jc.ErrorIsNil)
	err = m.Remove()
	c.Assert(err, jc.ErrorIsNil)
	a := s.newAgent(c, m)
	err = runWithTimeout(a)
	c.Assert(err, jc.ErrorIsNil)

	_, err = os.Stat(ac.DataDir())
	c.Assert(err, jc.Satisfies, os.IsNotExist)
}

func (s *MachineSuite) TestDyingMachine(c *gc.C) {
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	done := make(chan error)
	go func() {
		done <- a.Run(nil)
	}()
	defer func() {
		c.Check(a.Stop(), jc.ErrorIsNil)
	}()
	// Wait for configuration to be finished
	<-a.WorkersStarted()
	err := m.Destroy()
	c.Assert(err, jc.ErrorIsNil)
	select {
	case err := <-done:
		c.Assert(err, jc.ErrorIsNil)
	case <-time.After(watcher.Period * 5 / 4):
		// TODO(rog) Fix this so it doesn't wait for so long.
		// https://bugs.launchpad.net/juju-core/+bug/1163983
		c.Fatalf("timed out waiting for agent to terminate")
	}
	err = m.Refresh()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(m.Life(), gc.Equals, state.Dead)
}

func (s *MachineSuite) TestHostUnits(c *gc.C) {
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	ctx, reset := patchDeployContext(c, s.BackingState)
	defer reset()
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()

	// check that unassigned units don't trigger any deployments.
	svc := s.AddTestingService(c, "wordpress", s.AddTestingCharm(c, "wordpress"))
	u0, err := svc.AddUnit()
	c.Assert(err, jc.ErrorIsNil)
	u1, err := svc.AddUnit()
	c.Assert(err, jc.ErrorIsNil)

	ctx.waitDeployed(c)

	// assign u0, check it's deployed.
	err = u0.AssignToMachine(m)
	c.Assert(err, jc.ErrorIsNil)
	ctx.waitDeployed(c, u0.Name())

	// "start the agent" for u0 to prevent short-circuited remove-on-destroy;
	// check that it's kept deployed despite being Dying.
	err = u0.SetAgentStatus(status.StatusIdle, "", nil)
	c.Assert(err, jc.ErrorIsNil)
	err = u0.Destroy()
	c.Assert(err, jc.ErrorIsNil)
	ctx.waitDeployed(c, u0.Name())

	// add u1 to the machine, check it's deployed.
	err = u1.AssignToMachine(m)
	c.Assert(err, jc.ErrorIsNil)
	ctx.waitDeployed(c, u0.Name(), u1.Name())

	// make u0 dead; check the deployer recalls the unit and removes it from
	// state.
	err = u0.EnsureDead()
	c.Assert(err, jc.ErrorIsNil)
	ctx.waitDeployed(c, u1.Name())

	// The deployer actually removes the unit just after
	// removing its deployment, so we need to poll here
	// until it actually happens.
	for attempt := coretesting.LongAttempt.Start(); attempt.Next(); {
		if !attempt.HasNext() {
			c.Fatalf("timeout waiting for unit %q to be removed", u0.Name())
		}
		if err := u0.Refresh(); err == nil {
			c.Logf("waiting unit %q to be removed...", u0.Name())
			continue
		} else {
			c.Assert(err, jc.Satisfies, errors.IsNotFound)
			break
		}
	}

	// short-circuit-remove u1 after it's been deployed; check it's recalled
	// and removed from state.
	err = u1.Destroy()
	c.Assert(err, jc.ErrorIsNil)
	err = u1.Refresh()
	c.Assert(err, jc.Satisfies, errors.IsNotFound)
	ctx.waitDeployed(c)
}

func patchDeployContext(c *gc.C, st *state.State) (*fakeContext, func()) {
	ctx := &fakeContext{
		inited:   newSignal(),
		deployed: make(set.Strings),
	}
	orig := newDeployContext
	newDeployContext = func(dst *apideployer.State, agentConfig agent.Config) deployer.Context {
		ctx.st = st
		ctx.agentConfig = agentConfig
		ctx.inited.trigger()
		return ctx
	}
	return ctx, func() { newDeployContext = orig }
}

func (s *commonMachineSuite) setFakeMachineAddresses(c *gc.C, machine *state.Machine) {
	addrs := network.NewAddresses("0.1.2.3")
	err := machine.SetProviderAddresses(addrs...)
	c.Assert(err, jc.ErrorIsNil)
	// Set the addresses in the environ instance as well so that if the instance poller
	// runs it won't overwrite them.
	instId, err := machine.InstanceId()
	c.Assert(err, jc.ErrorIsNil)
	insts, err := s.Environ.Instances([]instance.Id{instId})
	c.Assert(err, jc.ErrorIsNil)
	dummy.SetInstanceAddresses(insts[0], addrs)
}

func (s *MachineSuite) TestManageModel(c *gc.C) {
	usefulVersion := version.Binary{
		Number: jujuversion.Current,
		Arch:   arch.HostArch(),
		Series: "quantal", // to match the charm created below
	}
	envtesting.AssertUploadFakeToolsVersions(c, s.DefaultToolsStorage, s.Environ.Config().AgentStream(), s.Environ.Config().AgentStream(), usefulVersion)
	// Prime agent with manage networking in additon to manage model to ensure the former is ignored.
	m, _, _ := s.primeAgent(c, state.JobManageModel, state.JobManageNetworking)
	op := make(chan dummy.Operation, 200)
	dummy.Listen(op)

	a := s.newAgent(c, m)
	// Make sure the agent is stopped even if the test fails.
	defer a.Stop()
	done := make(chan error)
	go func() {
		done <- a.Run(nil)
	}()
	c.Logf("started test agent, waiting for workers...")
	r0 := s.singularRecord.nextRunner(c)
	r0.waitForWorker(c, "txnpruner")

	// Check that the provisioner and firewaller are alive by doing
	// a rudimentary check that it responds to state changes.

	// Create an exposed service, and add a unit.
	charm := s.AddTestingCharm(c, "dummy")
	svc := s.AddTestingService(c, "test-service", charm)
	err := svc.SetExposed()
	c.Assert(err, jc.ErrorIsNil)
	units, err := juju.AddUnits(s.State, svc, 1, nil)
	c.Assert(err, jc.ErrorIsNil)

	// It should be allocated to a machine, which should then be provisioned.
	c.Logf("service %q added with 1 unit, waiting for unit %q's machine to be started...", svc.Name(), units[0].Name())
	c.Check(opRecvTimeout(c, s.State, op, dummy.OpStartInstance{}), gc.NotNil)
	c.Logf("machine hosting unit %q started, waiting for the unit to be deployed...", units[0].Name())
	s.waitProvisioned(c, units[0])

	// Open a port on the unit; it should be handled by the firewaller.
	c.Logf("unit %q deployed, opening port tcp/999...", units[0].Name())
	err = units[0].OpenPort("tcp", 999)
	c.Assert(err, jc.ErrorIsNil)
	c.Check(opRecvTimeout(c, s.State, op, dummy.OpOpenPorts{}), gc.NotNil)
	c.Logf("unit %q port tcp/999 opened, cleaning up...", units[0].Name())

	err = a.Stop()
	c.Assert(err, jc.ErrorIsNil)
	select {
	case err := <-done:
		c.Assert(err, jc.ErrorIsNil)
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timed out waiting for agent to terminate")
	}
	c.Logf("test agent stopped successfully.")
}

func (s *MachineSuite) TestManageModelRunsResumer(c *gc.C) {
	started := newSignal()
	s.AgentSuite.PatchValue(&resumer.NewResumer, func(st resumer.TransactionResumer) worker.Worker {
		started.trigger()
		return newDummyWorker()
	})

	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	defer a.Stop()
	go func() {
		c.Check(a.Run(nil), jc.ErrorIsNil)
	}()
	started.assertTriggered(c, "resumer worker to start")
}

const startWorkerWait = 250 * time.Millisecond

func (s *MachineSuite) TestManageModelRunsInstancePoller(c *gc.C) {
	s.AgentSuite.PatchValue(&instancepoller.ShortPoll, 500*time.Millisecond)
	usefulVersion := version.Binary{
		Number: jujuversion.Current,
		Arch:   arch.HostArch(),
		Series: "quantal", // to match the charm created below
	}
	envtesting.AssertUploadFakeToolsVersions(
		c, s.DefaultToolsStorage,
		s.Environ.Config().AgentStream(),
		s.Environ.Config().AgentStream(),
		usefulVersion,
	)
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	defer a.Stop()
	go func() {
		c.Check(a.Run(nil), jc.ErrorIsNil)
	}()

	// Add one unit to a service;
	charm := s.AddTestingCharm(c, "dummy")
	svc := s.AddTestingService(c, "test-service", charm)
	units, err := juju.AddUnits(s.State, svc, 1, nil)
	c.Assert(err, jc.ErrorIsNil)

	m, instId := s.waitProvisioned(c, units[0])
	insts, err := s.Environ.Instances([]instance.Id{instId})
	c.Assert(err, jc.ErrorIsNil)
	addrs := network.NewAddresses("1.2.3.4")
	dummy.SetInstanceAddresses(insts[0], addrs)
	dummy.SetInstanceStatus(insts[0], "running")

	for attempt := coretesting.LongAttempt.Start(); attempt.Next(); {
		if !attempt.HasNext() {
			c.Logf("final machine addresses: %#v", m.Addresses())
			c.Fatalf("timed out waiting for machine to get address")
		}
		err := m.Refresh()
		c.Assert(err, jc.ErrorIsNil)
		instStatus, err := m.InstanceStatus()
		c.Assert(err, jc.ErrorIsNil)
		c.Logf("found status is %q %q", instStatus.Status, instStatus.Message)
		if reflect.DeepEqual(m.Addresses(), addrs) && instStatus.Message == "running" {
			c.Logf("machine %q address updated: %+v", m.Id(), addrs)
			break
		}
		c.Logf("waiting for machine %q address to be updated", m.Id())
	}
}

func (s *MachineSuite) TestManageModelRunsPeergrouper(c *gc.C) {
	started := newSignal()
	s.AgentSuite.PatchValue(&peergrouperNew, func(st *state.State) (worker.Worker, error) {
		c.Check(st, gc.NotNil)
		started.trigger()
		return newDummyWorker(), nil
	})
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	defer a.Stop()
	go func() {
		c.Check(a.Run(nil), jc.ErrorIsNil)
	}()
	started.assertTriggered(c, "peergrouperworker to start")
}

func (s *MachineSuite) TestManageModelRunsDbLogPrunerIfFeatureFlagEnabled(c *gc.C) {
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()

	runner := s.singularRecord.nextRunner(c)
	runner.waitForWorker(c, "dblogpruner")
}

func (s *MachineSuite) TestManageModelCallsUseMultipleCPUs(c *gc.C) {
	// If it has been enabled, the JobManageModel agent should call utils.UseMultipleCPUs
	usefulVersion := version.Binary{
		Number: jujuversion.Current,
		Arch:   arch.HostArch(),
		Series: "quantal", // to match the charm created below
	}
	envtesting.AssertUploadFakeToolsVersions(
		c, s.DefaultToolsStorage, s.Environ.Config().AgentStream(), s.Environ.Config().AgentStream(), usefulVersion)
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	calledChan := make(chan struct{}, 1)
	s.AgentSuite.PatchValue(&useMultipleCPUs, func() { calledChan <- struct{}{} })
	// Now, start the agent, and observe that a JobManageModel agent
	// calls UseMultipleCPUs
	a := s.newAgent(c, m)
	defer a.Stop()
	go func() {
		c.Check(a.Run(nil), jc.ErrorIsNil)
	}()
	// Wait for configuration to be finished
	<-a.WorkersStarted()
	s.assertChannelActive(c, calledChan, "UseMultipleCPUs() to be called")

	c.Check(a.Stop(), jc.ErrorIsNil)
	// However, an agent that just JobHostUnits doesn't call UseMultipleCPUs
	m2, _, _ := s.primeAgent(c, state.JobHostUnits)
	a2 := s.newAgent(c, m2)
	defer a2.Stop()
	go func() {
		c.Check(a2.Run(nil), jc.ErrorIsNil)
	}()
	// Wait until all the workers have been started, and then kill everything
	<-a2.workersStarted
	c.Check(a2.Stop(), jc.ErrorIsNil)
	s.assertChannelInactive(c, calledChan, "UseMultipleCPUs() was called")
}

func (s *MachineSuite) waitProvisioned(c *gc.C, unit *state.Unit) (*state.Machine, instance.Id) {
	c.Logf("waiting for unit %q to be provisioned", unit)
	machineId, err := unit.AssignedMachineId()
	c.Assert(err, jc.ErrorIsNil)
	m, err := s.State.Machine(machineId)
	c.Assert(err, jc.ErrorIsNil)
	w := m.Watch()
	defer w.Stop()
	timeout := time.After(coretesting.LongWait)
	for {
		select {
		case <-timeout:
			c.Fatalf("timed out waiting for provisioning")
		case <-time.After(coretesting.ShortWait):
			s.State.StartSync()
		case _, ok := <-w.Changes():
			c.Assert(ok, jc.IsTrue)
			err := m.Refresh()
			c.Assert(err, jc.ErrorIsNil)
			if instId, err := m.InstanceId(); err == nil {
				c.Logf("unit provisioned with instance %s", instId)
				return m, instId
			} else {
				c.Check(err, jc.Satisfies, errors.IsNotProvisioned)
			}
		}
	}
}

func (s *MachineSuite) testUpgradeRequest(c *gc.C, agent runner, tag string, currentTools *tools.Tools) {
	newVers := version.Binary{
		Number: jujuversion.Current,
		Arch:   arch.HostArch(),
		Series: series.HostSeries(),
	}
	newVers.Patch++
	newTools := envtesting.AssertUploadFakeToolsVersions(
		c, s.DefaultToolsStorage, s.Environ.Config().AgentStream(), s.Environ.Config().AgentStream(), newVers)[0]
	err := s.State.SetModelAgentVersion(newVers.Number)
	c.Assert(err, jc.ErrorIsNil)
	err = runWithTimeout(agent)
	envtesting.CheckUpgraderReadyError(c, err, &upgrader.UpgradeReadyError{
		AgentName: tag,
		OldTools:  currentTools.Version,
		NewTools:  newTools.Version,
		DataDir:   s.DataDir(),
	})
}

func (s *MachineSuite) TestUpgradeRequest(c *gc.C) {
	m, _, currentTools := s.primeAgent(c, state.JobManageModel, state.JobHostUnits)
	a := s.newAgent(c, m)
	s.testUpgradeRequest(c, a, m.Tag().String(), currentTools)
	c.Assert(a.isInitialUpgradeCheckPending(), jc.IsTrue)
}

func (s *MachineSuite) TestNoUpgradeRequired(c *gc.C) {
	m, _, _ := s.primeAgent(c, state.JobManageModel, state.JobHostUnits)
	a := s.newAgent(c, m)
	done := make(chan error)
	go func() { done <- a.Run(nil) }()
	select {
	case <-a.initialUpgradeCheckComplete.Unlocked():
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timeout waiting for upgrade check")
	}
	defer a.Stop() // in case of failure
	s.waitStopped(c, state.JobManageModel, a, done)
	c.Assert(a.isInitialUpgradeCheckPending(), jc.IsFalse)
}

var fastDialOpts = api.DialOpts{
	Timeout:    coretesting.LongWait,
	RetryDelay: coretesting.ShortWait,
}

func (s *MachineSuite) waitStopped(c *gc.C, job state.MachineJob, a *MachineAgent, done chan error) {
	err := a.Stop()
	if job == state.JobManageModel {
		// When shutting down, the API server can be shut down before
		// the other workers that connect to it, so they get an error so
		// they then die, causing Stop to return an error.  It's not
		// easy to control the actual error that's received in this
		// circumstance so we just log it rather than asserting that it
		// is not nil.
		if err != nil {
			c.Logf("error shutting down state manager: %v", err)
		}
	} else {
		c.Assert(err, jc.ErrorIsNil)
	}

	select {
	case err := <-done:
		c.Assert(err, jc.ErrorIsNil)
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timed out waiting for agent to terminate")
	}
}

func (s *MachineSuite) assertJobWithState(
	c *gc.C,
	job state.MachineJob,
	test func(agent.Config, *state.State),
) {
	paramsJob := job.ToParams()
	if !paramsJob.NeedsState() {
		c.Fatalf("%v does not use state", paramsJob)
	}
	s.assertAgentOpensState(c, &reportOpenedState, job, func(cfg agent.Config, st interface{}) {
		test(cfg, st.(*state.State))
	})
}

// assertAgentOpensState asserts that a machine agent started with the
// given job will call the function pointed to by reportOpened. The
// agent's configuration and the value passed to reportOpened are then
// passed to the test function for further checking.
func (s *MachineSuite) assertAgentOpensState(c *gc.C, reportOpened *func(io.Closer), job state.MachineJob, test func(agent.Config, interface{})) {
	stm, conf, _ := s.primeAgent(c, job)
	a := s.newAgent(c, stm)
	defer a.Stop()
	logger.Debugf("new agent %#v", a)

	// All state jobs currently also run an APIWorker, so no
	// need to check for that here, like in assertJobWithState.
	agentAPI, done := s.waitForOpenState(c, reportOpened, a)
	test(conf, agentAPI)
	s.waitStopped(c, job, a, done)
}

func (s *MachineSuite) waitForOpenState(c *gc.C, reportOpened *func(io.Closer), a *MachineAgent) (interface{}, chan error) {
	agentAPIs := make(chan io.Closer, 1)
	s.AgentSuite.PatchValue(reportOpened, func(st io.Closer) {
		select {
		case agentAPIs <- st:
		default:
		}
	})

	done := make(chan error)
	go func() {
		done <- a.Run(nil)
	}()

	select {
	case agentAPI := <-agentAPIs:
		c.Assert(agentAPI, gc.NotNil)
		return agentAPI, done
	case <-time.After(coretesting.LongWait):
		c.Fatalf("API not opened")
	}
	panic("can't happen")
}

func (s *MachineSuite) TestManageModelServesAPI(c *gc.C) {
	s.assertJobWithState(c, state.JobManageModel, func(conf agent.Config, agentState *state.State) {
		apiInfo, ok := conf.APIInfo()
		c.Assert(ok, jc.IsTrue)
		st, err := api.Open(apiInfo, fastDialOpts)
		c.Assert(err, jc.ErrorIsNil)
		defer st.Close()
		m, err := apimachiner.NewState(st).Machine(conf.Tag().(names.MachineTag))
		c.Assert(err, jc.ErrorIsNil)
		c.Assert(m.Life(), gc.Equals, params.Alive)
	})
}

func (s *MachineSuite) assertAgentSetsToolsVersion(c *gc.C, job state.MachineJob) {
	vers := version.Binary{
		Number: jujuversion.Current,
		Arch:   arch.HostArch(),
		Series: series.HostSeries(),
	}
	vers.Minor++
	m, _, _ := s.primeAgentVersion(c, vers, job)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()

	timeout := time.After(coretesting.LongWait)
	for done := false; !done; {
		select {
		case <-timeout:
			c.Fatalf("timeout while waiting for agent version to be set")
		case <-time.After(coretesting.ShortWait):
			c.Log("Refreshing")
			err := m.Refresh()
			c.Assert(err, jc.ErrorIsNil)
			c.Log("Fetching agent tools")
			agentTools, err := m.AgentTools()
			c.Assert(err, jc.ErrorIsNil)
			c.Logf("(%v vs. %v)", agentTools.Version, jujuversion.Current)
			if agentTools.Version.Minor != jujuversion.Current.Minor {
				continue
			}
			c.Assert(agentTools.Version.Number, gc.DeepEquals, jujuversion.Current)
			done = true
		}
	}
}

func (s *MachineSuite) TestAgentSetsToolsVersionManageModel(c *gc.C) {
	s.assertAgentSetsToolsVersion(c, state.JobManageModel)
}

func (s *MachineSuite) TestAgentSetsToolsVersionHostUnits(c *gc.C) {
	s.assertAgentSetsToolsVersion(c, state.JobHostUnits)
}

func (s *MachineSuite) TestManageModelRunsCleaner(c *gc.C) {
	s.assertJobWithState(c, state.JobManageModel, func(conf agent.Config, agentState *state.State) {
		// Create a service and unit, and destroy the service.
		service := s.AddTestingService(c, "wordpress", s.AddTestingCharm(c, "wordpress"))
		unit, err := service.AddUnit()
		c.Assert(err, jc.ErrorIsNil)
		err = service.Destroy()
		c.Assert(err, jc.ErrorIsNil)

		// Check the unit was not yet removed.
		err = unit.Refresh()
		c.Assert(err, jc.ErrorIsNil)
		w := unit.Watch()
		defer w.Stop()

		// Trigger a sync on the state used by the agent, and wait
		// for the unit to be removed.
		agentState.StartSync()
		timeout := time.After(coretesting.LongWait)
		for done := false; !done; {
			select {
			case <-timeout:
				c.Fatalf("unit not cleaned up")
			case <-time.After(coretesting.ShortWait):
				s.State.StartSync()
			case <-w.Changes():
				err := unit.Refresh()
				if errors.IsNotFound(err) {
					done = true
				} else {
					c.Assert(err, jc.ErrorIsNil)
				}
			}
		}
	})
}

func (s *MachineSuite) TestJobManageModelRunsMinUnitsWorker(c *gc.C) {
	s.assertJobWithState(c, state.JobManageModel, func(_ agent.Config, agentState *state.State) {
		// Ensure that the MinUnits worker is alive by doing a simple check
		// that it responds to state changes: add a service, set its minimum
		// number of units to one, wait for the worker to add the missing unit.
		service := s.AddTestingService(c, "wordpress", s.AddTestingCharm(c, "wordpress"))
		err := service.SetMinUnits(1)
		c.Assert(err, jc.ErrorIsNil)
		w := service.Watch()
		defer w.Stop()

		// Trigger a sync on the state used by the agent, and wait for the unit
		// to be created.
		agentState.StartSync()
		timeout := time.After(coretesting.LongWait)
		for {
			select {
			case <-timeout:
				c.Fatalf("unit not created")
			case <-time.After(coretesting.ShortWait):
				s.State.StartSync()
			case <-w.Changes():
				units, err := service.AllUnits()
				c.Assert(err, jc.ErrorIsNil)
				if len(units) == 1 {
					return
				}
			}
		}
	})
}

func (s *MachineSuite) TestMachineAgentRunsAuthorisedKeysWorker(c *gc.C) {
	//TODO(bogdanteleaga): Fix once we get authentication worker up on windows
	if runtime.GOOS == "windows" {
		c.Skip("bug 1403084: authentication worker not yet implemented on windows")
	}
	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()

	// Update the keys in the environment.
	sshKey := sshtesting.ValidKeyOne.Key + " user@host"
	err := s.BackingState.UpdateModelConfig(map[string]interface{}{"authorized-keys": sshKey}, nil, nil)
	c.Assert(err, jc.ErrorIsNil)

	// Wait for ssh keys file to be updated.
	s.State.StartSync()
	timeout := time.After(coretesting.LongWait)
	sshKeyWithCommentPrefix := sshtesting.ValidKeyOne.Key + " Juju:user@host"
	for {
		select {
		case <-timeout:
			c.Fatalf("timeout while waiting for authorised ssh keys to change")
		case <-time.After(coretesting.ShortWait):
			s.State.StartSync()
			keys, err := ssh.ListKeys(authenticationworker.SSHUser, ssh.FullKeys)
			c.Assert(err, jc.ErrorIsNil)
			keysStr := strings.Join(keys, "\n")
			if sshKeyWithCommentPrefix != keysStr {
				continue
			}
			return
		}
	}
}

// opRecvTimeout waits for any of the given kinds of operation to
// be received from ops, and times out if not.
func opRecvTimeout(c *gc.C, st *state.State, opc <-chan dummy.Operation, kinds ...dummy.Operation) dummy.Operation {
	st.StartSync()
	timeout := time.After(coretesting.LongWait)
	for {
		select {
		case op := <-opc:
			for _, k := range kinds {
				if reflect.TypeOf(op) == reflect.TypeOf(k) {
					return op
				}
			}
			c.Logf("discarding unknown event %#v", op)
		case <-time.After(coretesting.ShortWait):
			st.StartSync()
		case <-timeout:
			c.Fatalf("time out wating for operation")
		}
	}
}

func (s *MachineSuite) TestMachineAgentSymlinks(c *gc.C) {
	stm, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, stm)
	defer a.Stop()
	_, done := s.waitForOpenState(c, &reportOpenedState, a)

	// Symlinks should have been created
	for _, link := range []string{jujuRun, jujuDumpLogs} {
		_, err := os.Stat(utils.EnsureBaseDir(a.rootDir, link))
		c.Assert(err, jc.ErrorIsNil, gc.Commentf(link))
	}

	s.waitStopped(c, state.JobManageModel, a, done)
}

func (s *MachineSuite) TestMachineAgentSymlinkJujuRunExists(c *gc.C) {
	if runtime.GOOS == "windows" {
		// Cannot make symlink to nonexistent file on windows or
		// create a file point a symlink to it then remove it
		c.Skip("Cannot test this on windows")
	}

	stm, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, stm)
	defer a.Stop()

	// Pre-create the symlinks, but pointing to the incorrect location.
	links := []string{jujuRun, jujuDumpLogs}
	a.rootDir = c.MkDir()
	for _, link := range links {
		fullLink := utils.EnsureBaseDir(a.rootDir, link)
		c.Assert(os.MkdirAll(filepath.Dir(fullLink), os.FileMode(0755)), jc.ErrorIsNil)
		c.Assert(symlink.New("/nowhere/special", fullLink), jc.ErrorIsNil, gc.Commentf(link))
	}

	// Start the agent and wait for it be running.
	_, done := s.waitForOpenState(c, &reportOpenedState, a)

	// juju-run symlink should have been recreated.
	for _, link := range links {
		fullLink := utils.EnsureBaseDir(a.rootDir, link)
		linkTarget, err := symlink.Read(fullLink)
		c.Assert(err, jc.ErrorIsNil)
		c.Assert(linkTarget, gc.Not(gc.Equals), "/nowhere/special", gc.Commentf(link))
	}

	s.waitStopped(c, state.JobManageModel, a, done)
}

func (s *MachineSuite) TestMachineAgentUninstall(c *gc.C) {
	m, ac, _ := s.primeAgent(c, state.JobHostUnits)
	err := m.EnsureDead()
	c.Assert(err, jc.ErrorIsNil)
	a := s.newAgent(c, m)
	err = runWithTimeout(a)
	c.Assert(err, jc.ErrorIsNil)

	// juju-run and juju-dumplogs symlinks should have been removed on
	// termination.
	for _, link := range []string{jujuRun, jujuDumpLogs} {
		_, err = os.Stat(utils.EnsureBaseDir(a.rootDir, link))
		c.Assert(err, jc.Satisfies, os.IsNotExist)
	}

	// data-dir should have been removed on termination
	_, err = os.Stat(ac.DataDir())
	c.Assert(err, jc.Satisfies, os.IsNotExist)
}

func (s *MachineSuite) TestMachineAgentRunsAPIAddressUpdaterWorker(c *gc.C) {
	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()

	// Update the API addresses.
	updatedServers := [][]network.HostPort{
		network.NewHostPorts(1234, "localhost"),
	}
	err := s.BackingState.SetAPIHostPorts(updatedServers)
	c.Assert(err, jc.ErrorIsNil)

	// Wait for config to be updated.
	for attempt := coretesting.LongAttempt.Start(); attempt.Next(); {
		s.BackingState.StartSync()
		if !attempt.HasNext() {
			break
		}
		addrs, err := a.CurrentConfig().APIAddresses()
		c.Assert(err, jc.ErrorIsNil)
		if reflect.DeepEqual(addrs, []string{"localhost:1234"}) {
			return
		}
	}
	c.Fatalf("timeout while waiting for agent config to change")
}

func (s *MachineSuite) TestMachineAgentRunsDiskManagerWorker(c *gc.C) {
	// Patch out the worker func before starting the agent.
	started := newSignal()
	newWorker := func(diskmanager.ListBlockDevicesFunc, diskmanager.BlockDeviceSetter) worker.Worker {
		started.trigger()
		return worker.NewNoOpWorker()
	}
	s.PatchValue(&diskmanager.NewWorker, newWorker)

	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	started.assertTriggered(c, "diskmanager worker to start")
}

func (s *MachineSuite) TestMongoUpgradeWorker(c *gc.C) {
	// Patch out the worker func before starting the agent.
	started := make(chan struct{})
	newWorker := func(*state.State, string, mongoupgrader.StopMongo) (worker.Worker, error) {
		close(started)
		return worker.NewNoOpWorker(), nil
	}
	s.PatchValue(&newUpgradeMongoWorker, newWorker)

	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()

	// Wait for worker to be started.
	s.State.StartSync()
	select {
	case <-started:
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timeout while waiting for mongo upgrader worker to start")
	}
}

func (s *MachineSuite) TestDiskManagerWorkerUpdatesState(c *gc.C) {
	expected := []storage.BlockDevice{{DeviceName: "whatever"}}
	s.PatchValue(&diskmanager.DefaultListBlockDevices, func() ([]storage.BlockDevice, error) {
		return expected, nil
	})

	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()

	// Wait for state to be updated.
	s.BackingState.StartSync()
	for attempt := coretesting.LongAttempt.Start(); attempt.Next(); {
		devices, err := s.BackingState.BlockDevices(m.MachineTag())
		c.Assert(err, jc.ErrorIsNil)
		if len(devices) > 0 {
			c.Assert(devices, gc.HasLen, 1)
			c.Assert(devices[0].DeviceName, gc.Equals, expected[0].DeviceName)
			return
		}
	}
	c.Fatalf("timeout while waiting for block devices to be recorded")
}

func (s *MachineSuite) TestMachineAgentDoesNotRunMetadataWorkerForHostUnits(c *gc.C) {
	s.checkMetadataWorkerNotRun(c, state.JobHostUnits, "can host units")
}

func (s *MachineSuite) TestMachineAgentDoesNotRunMetadataWorkerForManageNetworking(c *gc.C) {
	s.checkMetadataWorkerNotRun(c, state.JobManageNetworking, "can manage networking")
}

func (s *MachineSuite) TestMachineAgentDoesNotRunMetadataWorkerForNonSimpleStreamDependentProviders(c *gc.C) {
	s.checkMetadataWorkerNotRun(c, state.JobManageModel, "has provider which doesn't depend on simple streams")
}

func (s *MachineSuite) checkMetadataWorkerNotRun(c *gc.C, job state.MachineJob, suffix string) {
	// Patch out the worker func before starting the agent.
	started := newSignal()
	newWorker := func(cl *imagemetadata.Client) worker.Worker {
		started.trigger()
		return worker.NewNoOpWorker()
	}
	s.PatchValue(&newMetadataUpdater, newWorker)

	// Start the machine agent.
	m, _, _ := s.primeAgent(c, job)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	started.assertNotTriggered(c, startWorkerWait, "metadata update worker started")
}

func (s *MachineSuite) TestMachineAgentRunsMachineStorageWorker(c *gc.C) {
	m, _, _ := s.primeAgent(c, state.JobHostUnits)

	started := newSignal()
	newWorker := func(config storageprovisioner.Config) (worker.Worker, error) {
		c.Check(config.Scope, gc.Equals, m.Tag())
		c.Check(config.Validate(), jc.ErrorIsNil)
		started.trigger()
		return worker.NewNoOpWorker(), nil
	}
	s.PatchValue(&storageprovisioner.NewStorageProvisioner, newWorker)

	// Start the machine agent.
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	started.assertTriggered(c, "storage worker to start")
}

func (s *MachineSuite) TestMachineAgentRunsCertificateUpdateWorkerForController(c *gc.C) {
	started := newSignal()
	newUpdater := func(certupdater.AddressWatcher, certupdater.StateServingInfoGetter, certupdater.ModelConfigGetter,
		certupdater.APIHostPortsGetter, certupdater.StateServingInfoSetter,
	) worker.Worker {
		started.trigger()
		return worker.NewNoOpWorker()
	}
	s.PatchValue(&newCertificateUpdater, newUpdater)

	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	started.assertTriggered(c, "certificate to be updated")
}

func (s *MachineSuite) TestMachineAgentDoesNotRunsCertificateUpdateWorkerForNonController(c *gc.C) {
	started := newSignal()
	newUpdater := func(certupdater.AddressWatcher, certupdater.StateServingInfoGetter, certupdater.ModelConfigGetter,
		certupdater.APIHostPortsGetter, certupdater.StateServingInfoSetter,
	) worker.Worker {
		started.trigger()
		return worker.NewNoOpWorker()
	}
	s.PatchValue(&newCertificateUpdater, newUpdater)

	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	started.assertNotTriggered(c, startWorkerWait, "certificate was updated")
}

func (s *MachineSuite) TestCertificateUpdateWorkerUpdatesCertificate(c *gc.C) {
	// Set up the machine agent.
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	a.ReadConfig(names.NewMachineTag(m.Id()).String())

	// Set up check that certificate has been updated.
	updated := make(chan struct{})
	go func() {
		for {
			stateInfo, _ := a.CurrentConfig().StateServingInfo()
			srvCert, err := cert.ParseCert(stateInfo.Cert)
			c.Assert(err, jc.ErrorIsNil)
			sanIPs := make([]string, len(srvCert.IPAddresses))
			for i, ip := range srvCert.IPAddresses {
				sanIPs[i] = ip.String()
			}
			if len(sanIPs) == 1 && sanIPs[0] == "0.1.2.3" {
				close(updated)
				break
			}
			time.Sleep(10 * time.Millisecond)
		}
	}()

	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	s.assertChannelActive(c, updated, "certificate to be updated")
}

func (s *MachineSuite) TestCertificateDNSUpdated(c *gc.C) {
	// Disable the certificate work so it doesn't update the certificate.
	newUpdater := func(certupdater.AddressWatcher, certupdater.StateServingInfoGetter, certupdater.ModelConfigGetter,
		certupdater.APIHostPortsGetter, certupdater.StateServingInfoSetter,
	) worker.Worker {
		return worker.NewNoOpWorker()
	}
	s.PatchValue(&newCertificateUpdater, newUpdater)

	// Set up the machine agent.
	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)

	// Set up check that certificate has been updated when the agent starts.
	updated := make(chan struct{})
	expectedDnsNames := set.NewStrings("local", "juju-apiserver", "juju-mongodb")
	go func() {
		for {
			stateInfo, _ := a.CurrentConfig().StateServingInfo()
			srvCert, err := cert.ParseCert(stateInfo.Cert)
			c.Assert(err, jc.ErrorIsNil)
			certDnsNames := set.NewStrings(srvCert.DNSNames...)
			if !expectedDnsNames.Difference(certDnsNames).IsEmpty() {
				continue
			}
			pemContent, err := ioutil.ReadFile(filepath.Join(s.DataDir(), "server.pem"))
			c.Assert(err, jc.ErrorIsNil)
			if string(pemContent) == stateInfo.Cert+"\n"+stateInfo.PrivateKey {
				close(updated)
				break
			}
			time.Sleep(10 * time.Millisecond)
		}
	}()

	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	s.assertChannelActive(c, updated, "certificate to be updated")
}

func (s *MachineSuite) setupIgnoreAddresses(c *gc.C, expectedIgnoreValue bool) chan bool {
	ignoreAddressCh := make(chan bool, 1)
	s.AgentSuite.PatchValue(&machiner.NewMachiner, func(cfg machiner.Config) (worker.Worker, error) {
		select {
		case ignoreAddressCh <- cfg.ClearMachineAddressesOnStart:
		default:
		}

		// The test just cares that NewMachiner is called with the correct
		// value, nothing else is done with the worker.
		return newDummyWorker(), nil
	})

	attrs := coretesting.Attrs{"ignore-machine-addresses": expectedIgnoreValue}
	err := s.BackingState.UpdateModelConfig(attrs, nil, nil)
	c.Assert(err, jc.ErrorIsNil)
	return ignoreAddressCh
}

func (s *MachineSuite) TestMachineAgentIgnoreAddresses(c *gc.C) {
	for _, expectedIgnoreValue := range []bool{true, false} {
		ignoreAddressCh := s.setupIgnoreAddresses(c, expectedIgnoreValue)

		m, _, _ := s.primeAgent(c, state.JobHostUnits)
		a := s.newAgent(c, m)
		defer a.Stop()
		doneCh := make(chan error)
		go func() {
			doneCh <- a.Run(nil)
		}()

		select {
		case ignoreMachineAddresses := <-ignoreAddressCh:
			if ignoreMachineAddresses != expectedIgnoreValue {
				c.Fatalf("expected ignore-machine-addresses = %v, got = %v", expectedIgnoreValue, ignoreMachineAddresses)
			}
		case <-time.After(coretesting.LongWait):
			c.Fatalf("timed out waiting for the machiner to start")
		}
		s.waitStopped(c, state.JobHostUnits, a, doneCh)
	}
}

func (s *MachineSuite) TestMachineAgentIgnoreAddressesContainer(c *gc.C) {
	ignoreAddressCh := s.setupIgnoreAddresses(c, true)

	parent, err := s.State.AddMachine("quantal", state.JobHostUnits)
	c.Assert(err, jc.ErrorIsNil)
	m, err := s.State.AddMachineInsideMachine(
		state.MachineTemplate{
			Series: "trusty",
			Jobs:   []state.MachineJob{state.JobHostUnits},
		},
		parent.Id(),
		instance.LXC,
	)
	c.Assert(err, jc.ErrorIsNil)

	vers := version.Binary{
		Number: jujuversion.Current,
		Arch:   arch.HostArch(),
		Series: series.HostSeries(),
	}
	s.primeAgentWithMachine(c, m, vers)
	a := s.newAgent(c, m)
	defer a.Stop()
	doneCh := make(chan error)
	go func() {
		doneCh <- a.Run(nil)
	}()

	select {
	case ignoreMachineAddresses := <-ignoreAddressCh:
		if ignoreMachineAddresses {
			c.Fatalf("expected ignore-machine-addresses = false, got = true")
		}
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timed out waiting for the machiner to start")
	}
	s.waitStopped(c, state.JobHostUnits, a, doneCh)
}

func (s *MachineSuite) TestMachineAgentSetsPrepareRestore(c *gc.C) {
	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	c.Check(a.IsRestorePreparing(), jc.IsFalse)
	c.Check(a.IsRestoreRunning(), jc.IsFalse)
	err := a.PrepareRestore()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(a.IsRestorePreparing(), jc.IsTrue)
	c.Assert(a.IsRestoreRunning(), jc.IsFalse)
	err = a.PrepareRestore()
	c.Assert(err, gc.ErrorMatches, "already in restore mode")
}

func (s *MachineSuite) TestMachineAgentSetsRestoreInProgress(c *gc.C) {
	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	c.Check(a.IsRestorePreparing(), jc.IsFalse)
	c.Check(a.IsRestoreRunning(), jc.IsFalse)
	err := a.PrepareRestore()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(a.IsRestorePreparing(), jc.IsTrue)
	err = a.BeginRestore()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(a.IsRestoreRunning(), jc.IsTrue)
	err = a.BeginRestore()
	c.Assert(err, gc.ErrorMatches, "already restoring")
}

func (s *MachineSuite) TestMachineAgentRestoreRequiresPrepare(c *gc.C) {
	// Start the machine agent.
	m, _, _ := s.primeAgent(c, state.JobHostUnits)
	a := s.newAgent(c, m)
	go func() { c.Check(a.Run(nil), jc.ErrorIsNil) }()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()
	c.Check(a.IsRestorePreparing(), jc.IsFalse)
	c.Check(a.IsRestoreRunning(), jc.IsFalse)
	err := a.BeginRestore()
	c.Assert(err, gc.ErrorMatches, "not in restore mode, cannot begin restoration")
	c.Assert(a.IsRestoreRunning(), jc.IsFalse)
}

func (s *MachineSuite) TestControllerModelWorkers(c *gc.C) {
	tracker := newModelTracker(c)
	check := modelMatchFunc(c, tracker, append(
		alwaysModelWorkers, aliveModelWorkers...,
	))
	s.PatchValue(&modelManifolds, tracker.Manifolds)

	uuid := s.BackingState.ModelUUID()
	timeout := time.After(coretesting.LongWait)

	s.assertJobWithState(c, state.JobManageModel, func(_ agent.Config, _ *state.State) {
		for {
			if check(uuid) {
				break
			}
			select {
			case <-time.After(coretesting.ShortWait):
				s.BackingState.StartSync()
			case <-timeout:
				c.Fatalf("timed out waiting for workers")
			}
		}
	})
}

func (s *MachineSuite) TestAddressAllocationModelWorkers(c *gc.C) {
	s.SetFeatureFlags(feature.AddressAllocation)

	tracker := newModelTracker(c)
	almostAllWorkers := append(alwaysModelWorkers, aliveModelWorkers...)
	check := modelMatchFunc(c, tracker, append(
		almostAllWorkers, "address-cleaner",
	))
	s.PatchValue(&modelManifolds, tracker.Manifolds)

	uuid := s.BackingState.ModelUUID()
	timeout := time.After(coretesting.LongWait)

	s.assertJobWithState(c, state.JobManageModel, func(_ agent.Config, _ *state.State) {
		for {
			if check(uuid) {
				break
			}
			select {
			case <-time.After(coretesting.ShortWait):
				s.BackingState.StartSync()
			case <-timeout:
				c.Fatalf("timed out waiting for workers")
			}
		}
	})
}

func (s *MachineSuite) TestHostedModelWorkers(c *gc.C) {
	tracker := newModelTracker(c)
	check := modelMatchFunc(c, tracker, append(
		alwaysModelWorkers, aliveModelWorkers...,
	))
	s.PatchValue(&modelManifolds, tracker.Manifolds)

	st, closer := s.setUpNewModel(c)
	defer closer()
	uuid := st.ModelUUID()
	timeout := time.After(ReallyLongWait)

	s.assertJobWithState(c, state.JobManageModel, func(_ agent.Config, _ *state.State) {
		for {
			if check(uuid) {
				break
			}
			select {
			case <-time.After(coretesting.ShortWait):
				s.BackingState.StartSync()
			case <-timeout:
				c.Fatalf("timed out waiting for workers")
			}
		}
	})
}

func (s *MachineSuite) TestDyingModelCleanedUp(c *gc.C) {
	tracker := newModelTracker(c)
	check := modelMatchFunc(c, tracker, append(
		alwaysModelWorkers, deadModelWorkers...,
	))
	s.PatchValue(&modelManifolds, tracker.Manifolds)

	st, closer := s.setUpNewModel(c)
	defer closer()
	uuid := st.ModelUUID()
	timeout := time.After(ReallyLongWait)

	s.assertJobWithState(c, state.JobManageModel, func(_ agent.Config, _ *state.State) {
		model, err := st.Model()
		c.Assert(err, jc.ErrorIsNil)
		err = model.Destroy()
		c.Assert(err, jc.ErrorIsNil)

		// Wait for the running workers to imply that we've
		// passed beyond Dying...
		for {
			if check(uuid) {
				break
			}
			select {
			case <-time.After(coretesting.ShortWait):
				s.BackingState.StartSync()
			case <-timeout:
				c.Fatalf("timed out waiting for workers")
			}
		}

		// ...and verify that's reflected in the database.
		err = model.Refresh()
		c.Check(err, jc.ErrorIsNil)
		c.Check(model.Life(), gc.Equals, state.Dead)
	})
}

func (s *MachineSuite) TestModelWorkersRespectSingularResponsibilityFlag(c *gc.C) {

	// Grab responsibility for the model on behalf of another machine.
	claimer := s.BackingState.SingularClaimer()
	uuid := s.BackingState.ModelUUID()
	err := claimer.Claim(uuid, "machine-999-lxc-99", time.Hour)
	c.Assert(err, jc.ErrorIsNil)

	// Then run a normal model-tracking test, just checking for
	// a different set of workers.
	tracker := newModelTracker(c)
	check := modelMatchFunc(c, tracker, alwaysModelWorkers)
	s.PatchValue(&modelManifolds, tracker.Manifolds)

	timeout := time.After(coretesting.LongWait)
	s.assertJobWithState(c, state.JobManageModel, func(_ agent.Config, _ *state.State) {
		for {
			if check(uuid) {
				break
			}
			select {
			case <-time.After(coretesting.ShortWait):
				s.BackingState.StartSync()
			case <-timeout:
				c.Fatalf("timed out waiting for workers")
			}
		}
	})
}

func (s *MachineSuite) setUpNewModel(c *gc.C) (newSt *state.State, closer func()) {
	// Create a new environment, tests can now watch if workers start for it.
	newSt = s.Factory.MakeModel(c, nil)
	return newSt, func() {
		err := newSt.Close()
		c.Check(err, jc.ErrorIsNil)
	}
}

func (s *MachineSuite) TestReplicasetInitForNewController(c *gc.C) {
	if runtime.GOOS == "windows" {
		c.Skip("controllers on windows aren't supported")
	}

	s.fakeEnsureMongo.ServiceInstalled = false

	m, _, _ := s.primeAgent(c, state.JobManageModel)
	a := s.newAgent(c, m)
	agentConfig := a.CurrentConfig()

	err := a.ensureMongoServer(agentConfig)
	c.Assert(err, jc.ErrorIsNil)

	c.Assert(s.fakeEnsureMongo.EnsureCount, gc.Equals, 1)
	c.Assert(s.fakeEnsureMongo.InitiateCount, gc.Equals, 0)
}

// MachineWithCharmsSuite provides infrastructure for tests which need to
// work with charms.
type MachineWithCharmsSuite struct {
	commonMachineSuite
	charmtesting.CharmSuite

	machine *state.Machine
}

func (s *MachineWithCharmsSuite) SetUpSuite(c *gc.C) {
	s.commonMachineSuite.SetUpSuite(c)
	s.CharmSuite.SetUpSuite(c, &s.commonMachineSuite.JujuConnSuite)
}

func (s *MachineWithCharmsSuite) TearDownSuite(c *gc.C) {
	s.CharmSuite.TearDownSuite(c)
	s.commonMachineSuite.TearDownSuite(c)
}

func (s *MachineWithCharmsSuite) SetUpTest(c *gc.C) {
	s.commonMachineSuite.SetUpTest(c)
	s.CharmSuite.SetUpTest(c)
}

func (s *MachineWithCharmsSuite) TearDownTest(c *gc.C) {
	s.CharmSuite.TearDownTest(c)
	s.commonMachineSuite.TearDownTest(c)
}

func (s *MachineWithCharmsSuite) TestManageModelRunsCharmRevisionUpdater(c *gc.C) {
	m, _, _ := s.primeAgent(c, state.JobManageModel)

	s.SetupScenario(c)

	a := s.newAgent(c, m)
	go func() {
		c.Check(a.Run(nil), jc.ErrorIsNil)
	}()
	defer func() { c.Check(a.Stop(), jc.ErrorIsNil) }()

	checkRevision := func() bool {
		curl := charm.MustParseURL("cs:quantal/mysql")
		placeholder, err := s.State.LatestPlaceholderCharm(curl)
		return err == nil && placeholder.String() == curl.WithRevision(23).String()
	}
	success := false
	for attempt := coretesting.LongAttempt.Start(); attempt.Next(); {
		if success = checkRevision(); success {
			break
		}
	}
	c.Assert(success, jc.IsTrue)
}

type mongoSuite struct {
	coretesting.BaseSuite
}

func (s *mongoSuite) TestStateWorkerDialSetsWriteMajority(c *gc.C) {
	s.testStateWorkerDialSetsWriteMajority(c, true)
}

func (s *mongoSuite) TestStateWorkerDialDoesNotSetWriteMajorityWithoutReplsetConfig(c *gc.C) {
	s.testStateWorkerDialSetsWriteMajority(c, false)
}

func (s *mongoSuite) testStateWorkerDialSetsWriteMajority(c *gc.C, configureReplset bool) {
	inst := gitjujutesting.MgoInstance{
		EnableJournal: true,
		Params:        []string{"--replSet", "juju"},
	}
	err := inst.Start(coretesting.Certs)
	c.Assert(err, jc.ErrorIsNil)
	defer inst.Destroy()

	var expectedWMode string
	dialOpts := stateWorkerDialOpts
	dialOpts.Timeout = coretesting.LongWait
	if configureReplset {
		info := inst.DialInfo()
		info.Timeout = dialOpts.Timeout
		args := peergrouper.InitiateMongoParams{
			DialInfo:       info,
			MemberHostPort: inst.Addr(),
		}
		err = peergrouper.InitiateMongoServer(args)
		c.Assert(err, jc.ErrorIsNil)
		expectedWMode = "majority"
	} else {
		dialOpts.Direct = true
	}

	mongoInfo := mongo.Info{
		Addrs:  []string{inst.Addr()},
		CACert: coretesting.CACert,
	}
	session, err := mongo.DialWithInfo(mongoInfo, dialOpts)
	c.Assert(err, jc.ErrorIsNil)
	defer session.Close()

	safe := session.Safe()
	c.Assert(safe, gc.NotNil)
	c.Assert(safe.WMode, gc.Equals, expectedWMode)
	c.Assert(safe.J, jc.IsTrue) // always enabled
}

type mockAgentConfig struct {
	agent.Config
	providerType string
	tag          names.Tag
}

func (m *mockAgentConfig) Tag() names.Tag {
	return m.tag
}

func (m *mockAgentConfig) Value(key string) string {
	if key == agent.ProviderType {
		return m.providerType
	}
	return ""
}

type singularRunnerRecord struct {
	runnerC chan *fakeSingularRunner
}

func newSingularRunnerRecord() *singularRunnerRecord {
	return &singularRunnerRecord{
		runnerC: make(chan *fakeSingularRunner, 64),
	}
}

func (r *singularRunnerRecord) newSingularRunner(runner worker.Runner, conn singular.Conn) (worker.Runner, error) {
	sr, err := singular.New(runner, conn)
	if err != nil {
		return nil, err
	}
	fakeRunner := &fakeSingularRunner{
		Runner: sr,
		startC: make(chan string, 64),
	}
	r.runnerC <- fakeRunner
	return fakeRunner, nil
}

// nextRunner blocks until a new singular runner is created.
func (r *singularRunnerRecord) nextRunner(c *gc.C) *fakeSingularRunner {
	timeout := time.After(coretesting.LongWait)
	for {
		select {
		case r := <-r.runnerC:
			return r
		case <-timeout:
			c.Fatal("timed out waiting for singular runner to be created")
		}
	}
}

type fakeSingularRunner struct {
	worker.Runner
	startC chan string
}

func (r *fakeSingularRunner) StartWorker(name string, start func() (worker.Worker, error)) error {
	logger.Infof("starting fake worker %q", name)
	r.startC <- name
	return r.Runner.StartWorker(name, start)
}

// waitForWorker waits for a given worker to be started, returning all
// workers started while waiting.
func (r *fakeSingularRunner) waitForWorker(c *gc.C, target string) []string {
	var seen []string
	timeout := time.After(coretesting.LongWait)
	for {
		select {
		case <-time.After(coretesting.ShortWait):
			c.Logf("still waiting for %q; workers seen so far: %+v", target, seen)
		case workerName := <-r.startC:
			seen = append(seen, workerName)
			if workerName == target {
				c.Logf("target worker %q started; workers seen so far: %+v", workerName, seen)
				return seen
			}
			c.Logf("worker %q started; still waiting for %q; workers seen so far: %+v", workerName, target, seen)
		case <-timeout:
			c.Fatal("timed out waiting for " + target)
		}
	}
}

// waitForWorkers waits for a given worker to be started, returning all
// workers started while waiting.
func (r *fakeSingularRunner) waitForWorkers(c *gc.C, targets []string) []string {
	var seen []string
	seenTargets := make(map[string]bool)
	numSeenTargets := 0
	timeout := time.After(coretesting.LongWait)
	for {
		select {
		case workerName := <-r.startC:
			c.Logf("worker %q started; workers seen so far: %+v (len: %d, len(targets): %d)", workerName, seen, len(seen), len(targets))
			if seenTargets[workerName] == true {
				c.Fatal("worker started twice: " + workerName)
			}
			seenTargets[workerName] = true
			numSeenTargets++
			seen = append(seen, workerName)
			if numSeenTargets == len(targets) {
				c.Logf("all expected target workers started: %+v", seen)
				return seen
			}
			c.Logf("still waiting for workers %+v to start; numSeenTargets=%d", targets, numSeenTargets)
		case <-timeout:
			c.Fatalf("timed out waiting for %v", targets)
		}
	}
}

type mockMetricAPI struct {
	stop          chan struct{}
	cleanUpCalled chan struct{}
	sendCalled    chan struct{}
}

func newMockMetricAPI() *mockMetricAPI {
	return &mockMetricAPI{
		stop:          make(chan struct{}),
		cleanUpCalled: make(chan struct{}),
		sendCalled:    make(chan struct{}),
	}
}

func (m *mockMetricAPI) CleanupOldMetrics() error {
	go func() {
		select {
		case m.cleanUpCalled <- struct{}{}:
		case <-m.stop:
			break
		}
	}()
	return nil
}

func (m *mockMetricAPI) SendMetrics() error {
	go func() {
		select {
		case m.sendCalled <- struct{}{}:
		case <-m.stop:
			break
		}
	}()
	return nil
}

func (m *mockMetricAPI) SendCalled() <-chan struct{} {
	return m.sendCalled
}

func (m *mockMetricAPI) CleanupCalled() <-chan struct{} {
	return m.cleanUpCalled
}

func (m *mockMetricAPI) Stop() {
	close(m.stop)
}

type mockLoopDeviceManager struct {
	detachLoopDevicesArgRootfs string
	detachLoopDevicesArgPrefix string
}

func (m *mockLoopDeviceManager) DetachLoopDevices(rootfs, prefix string) error {
	m.detachLoopDevicesArgRootfs = rootfs
	m.detachLoopDevicesArgPrefix = prefix
	return nil
}

func newSignal() *signal {
	return &signal{ch: make(chan struct{})}
}

type signal struct {
	mu sync.Mutex
	ch chan struct{}
}

func (s *signal) triggered() <-chan struct{} {
	return s.ch
}

func (s *signal) assertTriggered(c *gc.C, thing string) {
	select {
	case <-s.triggered():
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timed out waiting for " + thing)
	}
}

func (s *signal) assertNotTriggered(c *gc.C, wait time.Duration, thing string) {
	select {
	case <-s.triggered():
		c.Fatalf("%v unexpectedly", thing)
	case <-time.After(wait):
	}
}

func (s *signal) trigger() {
	s.mu.Lock()
	defer s.mu.Unlock()

	select {
	case <-s.ch:
		// Already closed.
	default:
		close(s.ch)
	}
}