func (*writerBasicsSuite) TestRemoveDefaultWriter(c *gc.C) {
	defaultWriter, level, err := loggo.RemoveWriter("default")
	c.Assert(err, gc.IsNil)
	c.Assert(level, gc.Equals, loggo.TRACE)
	c.Assert(defaultWriter, gc.NotNil)

	// Trying again fails.
	defaultWriter, level, err = loggo.RemoveWriter("default")
	c.Assert(err, gc.ErrorMatches, `Writer "default" is not registered`)
	c.Assert(level, gc.Equals, loggo.UNSPECIFIED)
	c.Assert(defaultWriter, gc.IsNil)
}

func (s *SimpleStreamsToolsSuite) TestFindToolsFiltering(c *gc.C) {
	tw := &loggo.TestWriter{}
	c.Assert(loggo.RegisterWriter("filter-tester", tw, loggo.DEBUG), gc.IsNil)
	defer loggo.RemoveWriter("filter-tester")
	_, err := envtools.FindTools(
		s.env, 1, -1, coretools.Filter{Number: version.Number{Major: 1, Minor: 2, Patch: 3}}, envtools.DoNotAllowRetry)
	c.Assert(err, jc.Satisfies, errors.IsNotFound)
	// This is slightly overly prescriptive, but feel free to change or add
	// messages. This still helps to ensure that all log messages are
	// properly formed.
	messages := []jc.SimpleMessage{
		{loggo.INFO, "reading tools with major version 1"},
		{loggo.INFO, "filtering tools by version: \\d+\\.\\d+\\.\\d+"},
		{loggo.DEBUG, "no architecture specified when finding tools, looking for any"},
		{loggo.DEBUG, "no series specified when finding tools, looking for any"},
	}
	sources, err := envtools.GetMetadataSources(s.env)
	c.Assert(err, gc.IsNil)
	for i := 0; i < 2*len(sources); i++ {
		messages = append(messages,
			jc.SimpleMessage{loggo.DEBUG, `fetchData failed for .*`},
			jc.SimpleMessage{loggo.DEBUG, `cannot load index .*`})
	}
	c.Check(tw.Log, jc.LogMatches, messages)
}

func (s *syncToolsSuite) TestSyncToolsCommandDeprecatedDestination(c *gc.C) {
	called := false
	dir := c.MkDir()
	syncTools = func(sctx *sync.SyncContext) error {
		c.Assert(sctx.AllVersions, jc.IsFalse)
		c.Assert(sctx.DryRun, jc.IsFalse)
		c.Assert(sctx.Stream, gc.Equals, "released")
		c.Assert(sctx.Source, gc.Equals, "")
		c.Assert(sctx.TargetToolsUploader, gc.FitsTypeOf, sync.StorageToolsUploader{})
		uploader := sctx.TargetToolsUploader.(sync.StorageToolsUploader)
		url, err := uploader.Storage.URL("")
		c.Assert(err, jc.ErrorIsNil)
		c.Assert(url, gc.Equals, utils.MakeFileURL(dir))
		called = true
		return nil
	}
	// Register writer.
	var tw loggo.TestWriter
	c.Assert(loggo.RegisterWriter("deprecated-tester", &tw, loggo.DEBUG), gc.IsNil)
	defer loggo.RemoveWriter("deprecated-tester")
	// Add deprecated message to be checked.
	messages := []jc.SimpleMessage{
		{loggo.WARNING, "Use of the --destination flag is deprecated in 1.18. Please use --local-dir instead."},
	}
	// Run sync-tools command with --destination flag.
	ctx, err := runSyncToolsCommand(c, "-m", "test-target", "--destination", dir, "--stream", "released")
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(ctx, gc.NotNil)
	c.Assert(called, jc.IsTrue)
	// Check deprecated message was logged.
	c.Check(tw.Log(), jc.LogMatches, messages)
}

func (s *SimpleStreamsToolsSuite) TestFindToolsFiltering(c *gc.C) {
	var tw loggo.TestWriter
	c.Assert(loggo.RegisterWriter("filter-tester", &tw, loggo.TRACE), gc.IsNil)
	defer loggo.RemoveWriter("filter-tester")
	logger := loggo.GetLogger("juju.environs")
	defer logger.SetLogLevel(logger.LogLevel())
	logger.SetLogLevel(loggo.TRACE)

	_, err := envtools.FindTools(
		s.env, 1, -1, "released", coretools.Filter{Number: version.Number{Major: 1, Minor: 2, Patch: 3}})
	c.Assert(err, jc.Satisfies, errors.IsNotFound)
	// This is slightly overly prescriptive, but feel free to change or add
	// messages. This still helps to ensure that all log messages are
	// properly formed.
	messages := []jc.SimpleMessage{
		{loggo.INFO, "reading tools with major version 1"},
		{loggo.INFO, "filtering tools by version: \\d+\\.\\d+\\.\\d+"},
		{loggo.TRACE, "no architecture specified when finding tools, looking for "},
		{loggo.TRACE, "no series specified when finding tools, looking for \\[.*\\]"},
	}
	sources, err := envtools.GetMetadataSources(s.env)
	c.Assert(err, jc.ErrorIsNil)
	for i := 0; i < 2*len(sources); i++ {
		messages = append(messages,
			jc.SimpleMessage{loggo.TRACE, `fetchData failed for .*`},
			jc.SimpleMessage{loggo.TRACE, `cannot load index .*`})
	}
	c.Check(tw.Log(), jc.LogMatches, messages)
}

func (s *writerSuite) SetUpTest(c *gc.C) {
	loggo.ResetLoggers()
	loggo.RemoveWriter("default")
	s.logger = loggo.GetLogger("test.writer")
	// Make it so the logger itself writes all messages.
	s.logger.SetLogLevel(loggo.TRACE)
}

func (s *BenchmarksSuite) BenchmarkLoggingNoWriters(c *gc.C) {
	// No writers
	loggo.RemoveWriter("test")
	for i := 0; i < c.N; i++ {
		s.logger.Warningf("just a simple warning for %d", i)
	}
}

func (s *syncToolsSuite) TestSyncToolsCommandDeprecatedDestination(c *gc.C) {
	called := false
	dir := c.MkDir()
	syncTools = func(sctx *sync.SyncContext) error {
		c.Assert(sctx.AllVersions, gc.Equals, false)
		c.Assert(sctx.DryRun, gc.Equals, false)
		c.Assert(sctx.Dev, gc.Equals, false)
		c.Assert(sctx.Source, gc.Equals, "")
		url, err := sctx.Target.URL("")
		c.Assert(err, gc.IsNil)
		c.Assert(url, gc.Equals, "file://"+dir)
		called = true
		return nil
	}
	// Register writer.
	var tw loggo.TestWriter
	c.Assert(loggo.RegisterWriter("deprecated-tester", &tw, loggo.DEBUG), gc.IsNil)
	defer loggo.RemoveWriter("deprecated-tester")
	// Add deprecated message to be checked.
	messages := []jc.SimpleMessage{
		{loggo.WARNING, "Use of the --destination flag is deprecated in 1.18. Please use --local-dir instead."},
	}
	// Run sync-tools command with --destination flag.
	ctx, err := runSyncToolsCommand(c, "-e", "test-target", "--destination", dir)
	c.Assert(err, gc.IsNil)
	c.Assert(ctx, gc.NotNil)
	c.Assert(called, jc.IsTrue)
	// Check deprecated message was logged.
	c.Check(tw.Log(), jc.LogMatches, messages)
	s.Reset(c)
}

func (s *UpgradeSuite) captureLogs(c *gc.C) {
	c.Assert(loggo.RegisterWriter("upgrade-tests", &s.logWriter, loggo.INFO), gc.IsNil)
	s.AddCleanup(func(*gc.C) {
		loggo.RemoveWriter("upgrade-tests")
		s.logWriter.Clear()
	})
}

func (s *logwriterSuite) BenchmarkLoggingNoWritersNoFormat(c *gc.C) {
	// No writers
	loggo.RemoveWriter("test")
	for i := 0; i < c.N; i++ {
		s.logger.Warningf("just a simple warning")
	}
}

// Run runs a machine agent.
func (a *MachineAgent) Run(_ *cmd.Context) error {
	// Due to changes in the logging, and needing to care about old
	// environments that have been upgraded, we need to explicitly remove the
	// file writer if one has been added, otherwise we will get duplicate
	// lines of all logging in the log file.
	loggo.RemoveWriter("logfile")
	defer a.tomb.Done()
	logger.Infof("machine agent %v start (%s [%s])", a.Tag(), version.Current, runtime.Compiler)
	if err := a.ReadConfig(a.Tag()); err != nil {
		return fmt.Errorf("cannot read agent configuration: %v", err)
	}
	a.configChangedVal.Set(struct{}{})
	agentConfig := a.CurrentConfig()
	charm.CacheDir = filepath.Join(agentConfig.DataDir(), "charmcache")
	if err := a.createJujuRun(agentConfig.DataDir()); err != nil {
		return fmt.Errorf("cannot create juju run symlink: %v", err)
	}
	a.runner.StartWorker("api", a.APIWorker)
	a.runner.StartWorker("statestarter", a.newStateStarterWorker)
	a.runner.StartWorker("termination", func() (worker.Worker, error) {
		return terminationworker.NewWorker(), nil
	})
	// At this point, all workers will have been configured to start
	close(a.workersStarted)
	err := a.runner.Wait()
	if err == worker.ErrTerminateAgent {
		err = a.uninstallAgent(agentConfig)
	}
	err = agentDone(err)
	a.tomb.Kill(err)
	return err
}

func (c *SyncToolsCommand) Run(ctx *cmd.Context) (resultErr error) {
	// Register writer for output on screen.
	loggo.RegisterWriter("synctools", cmd.NewCommandLogWriter("juju.environs.sync", ctx.Stdout, ctx.Stderr), loggo.INFO)
	defer loggo.RemoveWriter("synctools")
	environ, cleanup, err := environFromName(ctx, c.EnvName, &resultErr, "Sync-tools")
	if err != nil {
		return err
	}
	defer cleanup()
	target := environ.Storage()
	if c.localDir != "" {
		target, err = filestorage.NewFileStorageWriter(c.localDir)
		if err != nil {
			return err
		}
	}

	// Prepare syncing.
	sctx := &sync.SyncContext{
		Target:       target,
		AllVersions:  c.allVersions,
		MajorVersion: c.majorVersion,
		MinorVersion: c.minorVersion,
		DryRun:       c.dryRun,
		Dev:          c.dev,
		Public:       c.public,
		Source:       c.source,
	}
	return syncTools(sctx)
}

func (s *MongoSuite) assertSuccessWithInstallStepFailCentOS(c *gc.C, exec []string, execNameFail string, returnCode int, expectedResult []jc.SimpleMessage) {
	type installs struct {
		series string
		pkg    string
	}
	test := installs{
		"centos7", "mongodb*",
	}

	for _, e := range exec {
		testing.PatchExecutableAsEchoArgs(c, s, e)
	}

	testing.PatchExecutableThrowError(c, s, execNameFail, returnCode)

	dataDir := c.MkDir()
	s.patchSeries(test.series)

	var tw loggo.TestWriter
	c.Assert(loggo.RegisterWriter("mongosuite", &tw, loggo.INFO), jc.ErrorIsNil)
	defer loggo.RemoveWriter("mongosuite")

	err := mongo.EnsureServer(makeEnsureServerParams(dataDir))
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(tw.Log(), jc.LogMatches, expectedResult)
}

func (s *MongoSuite) assertTestMongoGetFails(c *gc.C, series string, packageManager string) {
	s.patchSeries(series)

	// Any exit code from apt-get that isn't 0 or 100 will be treated
	// as unexpected, skipping the normal retry loop. failCmd causes
	// the command to exit with 1.
	binDir := c.MkDir()
	s.PatchEnvPathPrepend(binDir)
	failCmd(filepath.Join(binDir, packageManager))

	// Set the mongodb service as installed but not running.
	s.data.SetStatus(mongo.ServiceName, "installed")

	var tw loggo.TestWriter
	c.Assert(loggo.RegisterWriter("test-writer", &tw, loggo.ERROR), jc.ErrorIsNil)
	defer loggo.RemoveWriter("test-writer")

	dataDir := c.MkDir()
	err := mongo.EnsureServer(makeEnsureServerParams(dataDir))

	// Even though apt-get failed, EnsureServer should continue and
	// not return the error - even though apt-get failed, the Juju
	// mongodb package is most likely already installed.
	// The error should be logged however.
	c.Assert(err, jc.ErrorIsNil)

	c.Check(tw.Log(), jc.LogMatches, []jc.SimpleMessage{
		{loggo.ERROR, `packaging command failed: .+`},
		{loggo.ERROR, `cannot install/upgrade mongod \(will proceed anyway\): packaging command failed`},
	})

	// Verify that EnsureServer continued and started the mongodb service.
	c.Check(s.data.Installed(), gc.HasLen, 0)
	s.data.CheckCallNames(c, "Installed", "Exists", "Running", "Start")
}

func (s *MongoSuite) TestQuantalAptAddRepo(c *gc.C) {
	dir := c.MkDir()
	// patch manager.RunCommandWithRetry for repository addition:
	s.PatchValue(&manager.RunCommandWithRetry, func(string) (string, int, error) {
		return "", 1, fmt.Errorf("packaging command failed: exit status 1")
	})
	s.PatchEnvPathPrepend(dir)
	failCmd(filepath.Join(dir, "add-apt-repository"))
	mockShellCommand(c, &s.CleanupSuite, "apt-get")

	var tw loggo.TestWriter
	c.Assert(loggo.RegisterWriter("test-writer", &tw, loggo.ERROR), jc.ErrorIsNil)
	defer loggo.RemoveWriter("test-writer")

	// test that we call add-apt-repository only for quantal
	// (and that if it fails, we log the error)
	s.PatchValue(&version.Current.Series, "quantal")
	err := mongo.EnsureServer(makeEnsureServerParams(dir, ""))
	c.Assert(err, jc.ErrorIsNil)

	c.Assert(tw.Log(), jc.LogMatches, []jc.SimpleMessage{
		{loggo.ERROR, `cannot install/upgrade mongod \(will proceed anyway\): packaging command failed`},
	})

	s.PatchValue(&manager.RunCommandWithRetry, func(string) (string, int, error) {
		return "", 0, nil
	})
	s.PatchValue(&version.Current.Series, "trusty")
	failCmd(filepath.Join(dir, "mongod"))
	err = mongo.EnsureServer(makeEnsureServerParams(dir, ""))
	c.Assert(err, jc.ErrorIsNil)
}

func (s *BootstrapSuite) TestBootstrapJenvWarning(c *gc.C) {
	env, fake := makeEmptyFakeHome(c)
	defer fake.Restore()
	defaultSeriesVersion := version.Current
	defaultSeriesVersion.Series = config.PreferredSeries(env.Config())
	// Force a dev version by having an odd minor version number.
	// This is because we have not uploaded any tools and auto
	// upload is only enabled for dev versions.
	defaultSeriesVersion.Minor = 11
	s.PatchValue(&version.Current, defaultSeriesVersion)

	store, err := configstore.Default()
	c.Assert(err, gc.IsNil)
	ctx := coretesting.Context(c)
	environs.PrepareFromName("peckham", ctx, store)

	logger := "jenv.warning.test"
	testWriter := &loggo.TestWriter{}
	loggo.RegisterWriter(logger, testWriter, loggo.WARNING)
	defer loggo.RemoveWriter(logger)

	_, errc := runCommand(ctx, new(BootstrapCommand), "-e", "peckham")
	c.Assert(<-errc, gc.IsNil)
	c.Assert(testWriter.Log, jc.LogMatches, []string{"ignoring environments.yaml: using bootstrap config in .*"})
}

func (s *environSuite) TestEnvironmentChanges(c *gc.C) {
	originalConfig, err := s.State.EnvironConfig()
	c.Assert(err, gc.IsNil)

	logc := make(logChan, 1009)
	c.Assert(loggo.RegisterWriter("testing", logc, loggo.WARNING), gc.IsNil)
	defer loggo.RemoveWriter("testing")

	obs, err := worker.NewEnvironObserver(s.State)
	c.Assert(err, gc.IsNil)

	env := obs.Environ()
	c.Assert(env.Config().AllAttrs(), gc.DeepEquals, originalConfig.AllAttrs())
	var oldType string
	oldType = env.Config().AllAttrs()["type"].(string)

	info := s.MongoInfo(c)
	opts := mongo.DefaultDialOpts()
	st2, err := state.Open(info, opts, state.Policy(nil))
	defer st2.Close()

	// Change to an invalid configuration and check
	// that the observer's environment remains the same.
	st2.UpdateEnvironConfig(map[string]interface{}{"type": "invalid"}, nil, nil)
	st2.StartSync()

	// Wait for the observer to register the invalid environment
	timeout := time.After(coretesting.LongWait)
loop:
	for {
		select {
		case msg := <-logc:
			if strings.Contains(msg, "error creating Environ") {
				break loop
			}
		case <-timeout:
			c.Fatalf("timed out waiting to see broken environment")
		}
	}
	// Check that the returned environ is still the same.
	env = obs.Environ()
	c.Assert(env.Config().AllAttrs(), gc.DeepEquals, originalConfig.AllAttrs())

	// Change the environment back to a valid configuration
	// with a different name and check that we see it.
	st2.UpdateEnvironConfig(map[string]interface{}{"type": oldType, "name": "a-new-name"}, nil, nil)
	st2.StartSync()

	for a := coretesting.LongAttempt.Start(); a.Next(); {
		env := obs.Environ()
		if !a.HasNext() {
			c.Fatalf("timed out waiting for new environ")
		}
		if env.Config().Name() == "a-new-name" {
			break
		}
	}
}

func (s *BenchmarksSuite) setupTempFileWriter(c *gc.C) *os.File {
	loggo.RemoveWriter("test")
	logFile, err := ioutil.TempFile(c.MkDir(), "loggo-test")
	c.Assert(err, gc.IsNil)
	writer := loggo.NewSimpleWriter(logFile, loggo.DefaultFormatter)
	err = loggo.RegisterWriter("testfile", writer)
	c.Assert(err, gc.IsNil)
	return logFile
}

func (s *ConfigDeprecationSuite) setupLogger(c *gc.C) func() {
	var err error
	s.writer = &loggo.TestWriter{}
	err = loggo.RegisterWriter("test", s.writer, loggo.WARNING)
	c.Assert(err, jc.ErrorIsNil)
	return func() {
		_, _, err := loggo.RemoveWriter("test")
		c.Assert(err, jc.ErrorIsNil)
	}
}

func (s *wrenchSuite) SetUpTest(c *gc.C) {
	s.BaseSuite.SetUpTest(c)
	// BaseSuite turns off wrench so restore the non-testing default.
	wrench.SetEnabled(true)
	c.Assert(loggo.RegisterWriter("wrench-tests", &s.logWriter, loggo.TRACE), gc.IsNil)
	s.AddCleanup(func(*gc.C) {
		s.logWriter.Clear()
		loggo.RemoveWriter("wrench-tests")
	})
}

func (s *logwriterSuite) SetUpTest(c *gc.C) {
	loggo.ResetLoggers()
	loggo.RemoveWriter("default")
	s.writer = &loggo.TestWriter{}
	err := loggo.RegisterWriter("test", s.writer, loggo.TRACE)
	c.Assert(err, gc.IsNil)
	s.logger = loggo.GetLogger("test.writer")
	// Make it so the logger itself writes all messages.
	s.logger.SetLogLevel(loggo.TRACE)
}