func (s *BootstrapSuite) TestAutoUploadAfterFailedSync(c *gc.C) {
	s.PatchValue(&version.Current.Series, config.LatestLtsSeries())
	otherSeries := "quantal"

	env := s.setupAutoUploadTest(c, "1.7.3", otherSeries)
	// Run command and check for that upload has been run for tools matching the current juju version.
	opc, errc := runCommand(nullContext(c), new(BootstrapCommand))
	c.Assert(<-errc, gc.IsNil)
	c.Assert((<-opc).(dummy.OpPutFile).Env, gc.Equals, "peckham")
	list, err := envtools.FindTools(env, version.Current.Major, version.Current.Minor, coretools.Filter{}, false)
	c.Assert(err, gc.IsNil)
	c.Logf("found: " + list.String())
	urls := list.URLs()

	// We expect:
	//     supported LTS series precise, trusty,
	//     the specified series (quantal),
	//     and the environment's default series (raring).
	expectedVers := []version.Binary{
		version.MustParseBinary(fmt.Sprintf("1.7.3.1-%s-%s", "quantal", version.Current.Arch)),
		version.MustParseBinary(fmt.Sprintf("1.7.3.1-%s-%s", "raring", version.Current.Arch)),
		version.MustParseBinary(fmt.Sprintf("1.7.3.1-%s-%s", "precise", version.Current.Arch)),
		version.MustParseBinary(fmt.Sprintf("1.7.3.1-%s-%s", "trusty", version.Current.Arch)),
	}
	c.Assert(urls, gc.HasLen, len(expectedVers))
	for _, vers := range expectedVers {
		c.Logf("seeking: " + vers.String())
		_, found := urls[vers]
		c.Check(found, gc.Equals, true)
	}
}

func (s *simplestreamsSuite) assertWriteMetadata(c *gc.C, withMirrors bool) {
	var versionStrings = []string{
		"1.2.3-precise-amd64",
		"2.0.1-raring-amd64",
	}
	dir := c.MkDir()
	ttesting.MakeTools(c, dir, "releases", versionStrings)

	toolsList := coretools.List{
		{
			// If sha256/size is already known, do not recalculate
			Version: version.MustParseBinary("1.2.3-precise-amd64"),
			Size:    123,
			SHA256:  "abcd",
		}, {
			Version: version.MustParseBinary("2.0.1-raring-amd64"),
			// The URL is not used for generating metadata.
			URL: "bogus://",
		},
	}
	writer, err := filestorage.NewFileStorageWriter(dir)
	c.Assert(err, gc.IsNil)
	writeMirrors := tools.DoNotWriteMirrors
	if withMirrors {
		writeMirrors = tools.WriteMirrors
	}
	err = tools.MergeAndWriteMetadata(writer, toolsList, writeMirrors)
	c.Assert(err, gc.IsNil)
	metadata := ttesting.ParseMetadataFromDir(c, dir, withMirrors)
	assertMetadataMatches(c, dir, toolsList, metadata)
}

func (*metadataHelperSuite) TestMetadataFromTools(c *gc.C) {
	metadata := tools.MetadataFromTools(nil)
	c.Assert(metadata, gc.HasLen, 0)

	toolsList := coretools.List{{
		Version: version.MustParseBinary("1.2.3-precise-amd64"),
		Size:    123,
		SHA256:  "abc",
	}, {
		Version: version.MustParseBinary("2.0.1-raring-amd64"),
		URL:     "file:///tmp/releases/juju-2.0.1-raring-amd64.tgz",
		Size:    456,
		SHA256:  "xyz",
	}}
	metadata = tools.MetadataFromTools(toolsList)
	c.Assert(metadata, gc.HasLen, len(toolsList))
	for i, t := range toolsList {
		md := metadata[i]
		c.Assert(md.Release, gc.Equals, t.Version.Series)
		c.Assert(md.Version, gc.Equals, t.Version.Number.String())
		c.Assert(md.Arch, gc.Equals, t.Version.Arch)
		// FullPath is only filled out when reading tools using simplestreams.
		// It's not needed elsewhere and requires a URL() call.
		c.Assert(md.FullPath, gc.Equals, "")
		c.Assert(md.Path, gc.Equals, tools.StorageName(t.Version)[len("tools/"):])
		c.Assert(md.FileType, gc.Equals, "tar.gz")
		c.Assert(md.Size, gc.Equals, t.Size)
		c.Assert(md.SHA256, gc.Equals, t.SHA256)
	}
}

func (s *simplestreamsSuite) TestWriteMetadataMergeWithExisting(c *gc.C) {
	dir := c.MkDir()
	existingToolsList := coretools.List{
		{
			Version: version.MustParseBinary("1.2.3-precise-amd64"),
			Size:    123,
			SHA256:  "abc",
		}, {
			Version: version.MustParseBinary("2.0.1-raring-amd64"),
			Size:    456,
			SHA256:  "xyz",
		},
	}
	writer, err := filestorage.NewFileStorageWriter(dir)
	c.Assert(err, gc.IsNil)
	err = tools.MergeAndWriteMetadata(writer, existingToolsList, tools.DoNotWriteMirrors)
	c.Assert(err, gc.IsNil)
	newToolsList := coretools.List{
		existingToolsList[0],
		{
			Version: version.MustParseBinary("2.1.0-raring-amd64"),
			Size:    789,
			SHA256:  "def",
		},
	}
	err = tools.MergeAndWriteMetadata(writer, newToolsList, tools.DoNotWriteMirrors)
	c.Assert(err, gc.IsNil)
	requiredToolsList := append(existingToolsList, newToolsList[1])
	metadata := ttesting.ParseMetadataFromDir(c, dir, false)
	assertMetadataMatches(c, dir, requiredToolsList, metadata)
}

func (s *UpgraderSuite) TestUpgraderUpgradesImmediately(c *gc.C) {
	stor := s.Conn.Environ.Storage()
	oldTools := envtesting.PrimeTools(c, stor, s.DataDir(), version.MustParseBinary("5.4.3-precise-amd64"))
	s.PatchValue(&version.Current, oldTools.Version)
	newTools := envtesting.AssertUploadFakeToolsVersions(
		c, stor, version.MustParseBinary("5.4.5-precise-amd64"))[0]
	err := statetesting.SetAgentVersion(s.State, newTools.Version.Number)
	c.Assert(err, gc.IsNil)

	// Make the download take a while so that we verify that
	// the download happens before the upgrader checks if
	// it's been stopped.
	dummy.SetStorageDelay(coretesting.ShortWait)

	u := s.makeUpgrader()
	err = u.Stop()
	envtesting.CheckUpgraderReadyError(c, err, &upgrader.UpgradeReadyError{
		AgentName: s.machine.Tag(),
		OldTools:  oldTools.Version,
		NewTools:  newTools.Version,
		DataDir:   s.DataDir(),
	})
	foundTools, err := agenttools.ReadTools(s.DataDir(), newTools.Version)
	c.Assert(err, gc.IsNil)
	envtesting.CheckTools(c, foundTools, newTools)
}

func (s *bootstrapSuite) TestSetBootstrapTools(c *gc.C) {
	availableVersions := []version.Binary{
		version.MustParseBinary("1.18.0-trusty-arm64"),
		version.MustParseBinary("1.18.1-trusty-arm64"),
		version.MustParseBinary("1.18.1.1-trusty-arm64"),
		version.MustParseBinary("1.18.1.2-trusty-arm64"),
		version.MustParseBinary("1.18.1.3-trusty-arm64"),
	}
	availableTools := make(tools.List, len(availableVersions))
	for i, v := range availableVersions {
		availableTools[i] = &tools.Tools{Version: v}
	}

	type test struct {
		currentVersion       version.Number
		expectedTools        version.Number
		expectedAgentVersion version.Number
	}
	tests := []test{{
		currentVersion:       version.MustParse("1.18.0"),
		expectedTools:        version.MustParse("1.18.0"),
		expectedAgentVersion: version.MustParse("1.18.1.3"),
	}, {
		currentVersion:       version.MustParse("1.18.1.4"),
		expectedTools:        version.MustParse("1.18.1.3"),
		expectedAgentVersion: version.MustParse("1.18.1.3"),
	}, {
		// build number is ignored unless major/minor don't
		// match the latest.
		currentVersion:       version.MustParse("1.18.1.2"),
		expectedTools:        version.MustParse("1.18.1.3"),
		expectedAgentVersion: version.MustParse("1.18.1.3"),
	}, {
		// If the current patch level exceeds whatever's in
		// the tools source (e.g. when bootstrapping from trunk)
		// then the latest available tools will be chosen.
		currentVersion:       version.MustParse("1.18.2"),
		expectedTools:        version.MustParse("1.18.1.3"),
		expectedAgentVersion: version.MustParse("1.18.1.3"),
	}}

	env := newEnviron("foo", useDefaultKeys, nil)
	for i, t := range tests {
		c.Logf("test %d: %+v", i, t)
		cfg, err := env.Config().Remove([]string{"agent-version"})
		c.Assert(err, gc.IsNil)
		err = env.SetConfig(cfg)
		c.Assert(err, gc.IsNil)
		s.PatchValue(&version.Current.Number, t.currentVersion)
		bootstrapTools, err := bootstrap.SetBootstrapTools(env, availableTools)
		c.Assert(err, gc.IsNil)
		c.Assert(bootstrapTools, gc.HasLen, 1)
		c.Assert(bootstrapTools[0].Version.Number, gc.Equals, t.expectedTools)
		agentVersion, _ := env.Config().AgentVersion()
		c.Assert(agentVersion, gc.Equals, t.expectedAgentVersion)
	}
}

func (s *UpgraderSuite) TestUpgraderRetryAndChanged(c *gc.C) {
	stor := s.Conn.Environ.Storage()
	oldTools := envtesting.PrimeTools(c, stor, s.DataDir(), version.MustParseBinary("5.4.3-precise-amd64"))
	s.PatchValue(&version.Current, oldTools.Version)
	newTools := envtesting.AssertUploadFakeToolsVersions(
		c, stor, version.MustParseBinary("5.4.5-precise-amd64"))[0]
	err := statetesting.SetAgentVersion(s.State, newTools.Version.Number)
	c.Assert(err, gc.IsNil)

	retryc := make(chan time.Time)
	*upgrader.RetryAfter = func() <-chan time.Time {
		c.Logf("replacement retry after")
		return retryc
	}
	dummy.Poison(s.Conn.Environ.Storage(), envtools.StorageName(newTools.Version), fmt.Errorf("a non-fatal dose"))
	u := s.makeUpgrader()
	defer u.Stop()

	for i := 0; i < 3; i++ {
		select {
		case retryc <- time.Now():
		case <-time.After(coretesting.LongWait):
			c.Fatalf("upgrader did not retry (attempt %d)", i)
		}
	}

	// Make it upgrade to some newer tools that can be
	// downloaded ok; it should stop retrying, download
	// the newer tools and exit.
	newerTools := envtesting.AssertUploadFakeToolsVersions(
		c, s.Conn.Environ.Storage(), version.MustParseBinary("5.4.6-precise-amd64"))[0]

	err = statetesting.SetAgentVersion(s.State, newerTools.Version.Number)
	c.Assert(err, gc.IsNil)

	s.BackingState.StartSync()
	done := make(chan error)
	go func() {
		done <- u.Wait()
	}()
	select {
	case err := <-done:
		envtesting.CheckUpgraderReadyError(c, err, &upgrader.UpgradeReadyError{
			AgentName: s.machine.Tag(),
			OldTools:  oldTools.Version,
			NewTools:  newerTools.Version,
			DataDir:   s.DataDir(),
		})
	case <-time.After(coretesting.LongWait):
		c.Fatalf("upgrader did not quit after upgrading")
	}
}

func (s *toolsSuite) TestUploadFakeSeries(c *gc.C) {
	// Make some fake tools.
	localStorage := c.MkDir()
	vers := version.MustParseBinary("1.9.0-quantal-amd64")
	versionStrings := []string{vers.String()}
	expectedTools := ttesting.MakeToolsWithCheckSum(c, localStorage, "releases", versionStrings)

	// Now try uploading them.
	toolsFile := tools.StorageName(vers)
	params := "?binaryVersion=" + vers.String() + "&series=precise,trusty"
	resp, err := s.uploadRequest(c, s.toolsURI(c, params), true, path.Join(localStorage, toolsFile))
	c.Assert(err, gc.IsNil)

	// Check the response.
	stor := s.Conn.Environ.Storage()
	toolsURL, err := stor.URL(tools.StorageName(vers))
	c.Assert(err, gc.IsNil)
	expectedTools[0].URL = toolsURL
	s.assertUploadResponse(c, resp, expectedTools[0])

	// Check the contents.
	for _, series := range []string{"precise", "quantal", "trusty"} {
		toolsVersion := vers
		toolsVersion.Series = series
		r, err := stor.Get(tools.StorageName(toolsVersion))
		c.Assert(err, gc.IsNil)
		uploadedData, err := ioutil.ReadAll(r)
		c.Assert(err, gc.IsNil)
		expectedData, err := ioutil.ReadFile(filepath.Join(localStorage, tools.StorageName(vers)))
		c.Assert(err, gc.IsNil)
		c.Assert(uploadedData, gc.DeepEquals, expectedData)
	}
}

func testAgentTools(c *gc.C, obj tooler, agent string) {
	// object starts with zero'd tools.
	t, err := obj.AgentTools()
	c.Assert(t, gc.IsNil)
	c.Assert(err, jc.Satisfies, errors.IsNotFound)

	err = obj.SetAgentVersion(version.Binary{})
	c.Assert(err, gc.ErrorMatches, fmt.Sprintf("cannot set agent version for %s: empty series or arch", agent))

	v2 := version.MustParseBinary("7.8.9-foo-bar")
	err = obj.SetAgentVersion(v2)
	c.Assert(err, gc.IsNil)
	t3, err := obj.AgentTools()
	c.Assert(err, gc.IsNil)
	c.Assert(t3.Version, gc.DeepEquals, v2)
	err = obj.Refresh()
	c.Assert(err, gc.IsNil)
	t3, err = obj.AgentTools()
	c.Assert(err, gc.IsNil)
	c.Assert(t3.Version, gc.DeepEquals, v2)

	testWhenDying(c, obj, noErr, deadErr, func() error {
		return obj.SetAgentVersion(v2)
	})
}

func (s *BootstrapSuite) runAllowRetriesTest(c *gc.C, test bootstrapRetryTest) {
	toolsVersions := envtesting.VAll
	if test.version != "" {
		useVersion := strings.Replace(test.version, "%LTS%", config.LatestLtsSeries(), 1)
		testVersion := version.MustParseBinary(useVersion)
		s.PatchValue(&version.Current, testVersion)
		if test.addVersionToSource {
			toolsVersions = append([]version.Binary{}, toolsVersions...)
			toolsVersions = append(toolsVersions, testVersion)
		}
	}
	_, fake := makeEmptyFakeHome(c)
	defer fake.Restore()
	sourceDir := createToolsSource(c, toolsVersions)
	s.PatchValue(&envtools.DefaultBaseURL, sourceDir)

	var findToolsRetryValues []bool
	mockFindTools := func(cloudInst environs.ConfigGetter, majorVersion, minorVersion int,
		filter coretools.Filter, allowRetry bool) (list coretools.List, err error) {
		findToolsRetryValues = append(findToolsRetryValues, allowRetry)
		return nil, errors.NotFoundf("tools")
	}

	restore := envtools.TestingPatchBootstrapFindTools(mockFindTools)
	defer restore()

	_, errc := runCommand(nullContext(c), new(BootstrapCommand), test.args...)
	err := <-errc
	c.Check(findToolsRetryValues, gc.DeepEquals, test.expectedAllowRetry)
	stripped := strings.Replace(err.Error(), "\n", "", -1)
	c.Check(stripped, gc.Matches, test.err)
}

func (*metadataHelperSuite) TestResolveMetadata(c *gc.C) {
	var versionStrings = []string{"1.2.3-precise-amd64"}
	dir := c.MkDir()
	ttesting.MakeTools(c, dir, "releases", versionStrings)
	toolsList := coretools.List{{
		Version: version.MustParseBinary(versionStrings[0]),
		Size:    123,
		SHA256:  "abc",
	}}

	stor, err := filestorage.NewFileStorageReader(dir)
	c.Assert(err, gc.IsNil)
	err = tools.ResolveMetadata(stor, nil)
	c.Assert(err, gc.IsNil)

	// We already have size/sha256, so ensure that storage isn't consulted.
	countingStorage := &countingStorage{StorageReader: stor}
	metadata := tools.MetadataFromTools(toolsList)
	err = tools.ResolveMetadata(countingStorage, metadata)
	c.Assert(err, gc.IsNil)
	c.Assert(countingStorage.counter, gc.Equals, 0)

	// Now clear size/sha256, and check that it is called, and
	// the size/sha256 sum are updated.
	metadata[0].Size = 0
	metadata[0].SHA256 = ""
	err = tools.ResolveMetadata(countingStorage, metadata)
	c.Assert(err, gc.IsNil)
	c.Assert(countingStorage.counter, gc.Equals, 1)
	c.Assert(metadata[0].Size, gc.Not(gc.Equals), 0)
	c.Assert(metadata[0].SHA256, gc.Not(gc.Equals), "")
}

func makeTools(c *gc.C, metadataDir, subdir string, versionStrings []string, withCheckSum bool) coretools.List {
	toolsDir := filepath.Join(metadataDir, storage.BaseToolsPath)
	if subdir != "" {
		toolsDir = filepath.Join(toolsDir, subdir)
	}
	c.Assert(os.MkdirAll(toolsDir, 0755), gc.IsNil)
	var toolsList coretools.List
	for _, versionString := range versionStrings {
		binary := version.MustParseBinary(versionString)
		path := filepath.Join(toolsDir, fmt.Sprintf("juju-%s.tgz", binary))
		data := binary.String()
		err := ioutil.WriteFile(path, []byte(data), 0644)
		c.Assert(err, gc.IsNil)
		tool := &coretools.Tools{
			Version: binary,
			URL:     path,
		}
		if withCheckSum {
			tool.Size, tool.SHA256 = SHA256sum(c, path)
		}
		toolsList = append(toolsList, tool)
	}
	// Write the tools metadata.
	stor, err := filestorage.NewFileStorageWriter(metadataDir)
	c.Assert(err, gc.IsNil)
	err = tools.MergeAndWriteMetadata(stor, toolsList, false)
	c.Assert(err, gc.IsNil)
	return toolsList
}

func newSimpleTools(vers string) *tools.Tools {
	return &tools.Tools{
		URL:     "http://foo.com/tools/releases/juju" + vers + ".tgz",
		Version: version.MustParseBinary(vers),
		Size:    10,
		SHA256:  "1234",
	}
}

func newTools(vers, url string) *tools.Tools {
	return &tools.Tools{
		Version: version.MustParseBinary(vers),
		URL:     url,
		Size:    10,
		SHA256:  "1234",
	}
}

func (t *ToolsSuite) TestChangeAgentTools(c *gc.C) {
	files := []*testing.TarFile{
		testing.NewTarFile("jujuc", 0755, "juju executable"),
		testing.NewTarFile("jujud", 0755, "jujuc executable"),
	}
	data, checksum := testing.TarGz(files...)
	testTools := &coretest.Tools{
		URL:     "http://foo/bar1",
		Version: version.MustParseBinary("1.2.3-foo-bar"),
		Size:    int64(len(data)),
		SHA256:  checksum,
	}
	err := agenttools.UnpackTools(t.dataDir, testTools, bytes.NewReader(data))
	c.Assert(err, gc.IsNil)

	gotTools, err := agenttools.ChangeAgentTools(t.dataDir, "testagent", testTools.Version)
	c.Assert(err, gc.IsNil)
	c.Assert(*gotTools, gc.Equals, *testTools)

	assertDirNames(c, t.toolsDir(), []string{"1.2.3-foo-bar", "testagent"})
	assertDirNames(c, agenttools.ToolsDir(t.dataDir, "testagent"), []string{"jujuc", "jujud", toolsFile})

	// Upgrade again to check that the link replacement logic works ok.
	files2 := []*testing.TarFile{
		testing.NewTarFile("foo", 0755, "foo content"),
		testing.NewTarFile("bar", 0755, "bar content"),
	}
	data2, checksum2 := testing.TarGz(files2...)
	tools2 := &coretest.Tools{
		URL:     "http://foo/bar2",
		Version: version.MustParseBinary("1.2.4-foo-bar"),
		Size:    int64(len(data2)),
		SHA256:  checksum2,
	}
	err = agenttools.UnpackTools(t.dataDir, tools2, bytes.NewReader(data2))
	c.Assert(err, gc.IsNil)

	gotTools, err = agenttools.ChangeAgentTools(t.dataDir, "testagent", tools2.Version)
	c.Assert(err, gc.IsNil)
	c.Assert(*gotTools, gc.Equals, *tools2)

	assertDirNames(c, t.toolsDir(), []string{"1.2.3-foo-bar", "1.2.4-foo-bar", "testagent"})
	assertDirNames(c, agenttools.ToolsDir(t.dataDir, "testagent"), []string{"foo", "bar", toolsFile})
}

func (s *StorageSuite) TestReadList(c *gc.C) {
	store := s.env.Storage()
	v001 := version.MustParseBinary("0.0.1-precise-amd64")
	v100 := version.MustParseBinary("1.0.0-precise-amd64")
	v101 := version.MustParseBinary("1.0.1-precise-amd64")
	v111 := version.MustParseBinary("1.1.1-precise-amd64")
	agentTools := envtesting.AssertUploadFakeToolsVersions(c, store, v001, v100, v101, v111)
	t001 := agentTools[0]
	t100 := agentTools[1]
	t101 := agentTools[2]
	t111 := agentTools[3]

	for i, t := range []struct {
		majorVersion,
		minorVersion int
		list coretools.List
	}{{
		0, 0, coretools.List{t001},
	}, {
		1, 0, coretools.List{t100, t101},
	}, {
		1, 1, coretools.List{t111},
	}, {
		1, -1, coretools.List{t100, t101, t111},
	}, {
		1, 2, nil,
	}, {
		2, 0, nil,
	}} {
		c.Logf("test %d", i)
		list, err := envtools.ReadList(store, t.majorVersion, t.minorVersion)
		if t.list != nil {
			c.Assert(err, gc.IsNil)
			// ReadList doesn't set the Size of SHA256, so blank out those attributes.
			for _, tool := range t.list {
				tool.Size = 0
				tool.SHA256 = ""
			}
			c.Assert(list, gc.DeepEquals, t.list)
		} else {
			c.Assert(err, gc.Equals, coretools.ErrNoMatches)
		}
	}
}

func (s *unitUpgraderSuite) TestWatchAPIVersion(c *gc.C) {
	w, err := s.st.WatchAPIVersion(s.rawUnit.Tag())
	c.Assert(err, gc.IsNil)
	defer statetesting.AssertStop(c, w)
	wc := statetesting.NewNotifyWatcherC(c, s.BackingState, w)
	// Initial event
	wc.AssertOneChange()
	vers := version.MustParseBinary("10.20.34-quantal-amd64")
	err = s.rawMachine.SetAgentVersion(vers)
	c.Assert(err, gc.IsNil)
	// One change noticing the new version
	wc.AssertOneChange()
	vers = version.MustParseBinary("10.20.35-quantal-amd64")
	err = s.rawMachine.SetAgentVersion(vers)
	c.Assert(err, gc.IsNil)
	wc.AssertOneChange()
	statetesting.AssertStop(c, w)
	wc.AssertClosed()
}

func (s *UpgraderSuite) TestUpgraderRefusesToDowngradeMinorVersions(c *gc.C) {
	stor := s.Conn.Environ.Storage()
	origTools := envtesting.PrimeTools(c, stor, s.DataDir(), version.MustParseBinary("5.4.3-precise-amd64"))
	s.PatchValue(&version.Current, origTools.Version)
	downgradeTools := envtesting.AssertUploadFakeToolsVersions(
		c, stor, version.MustParseBinary("5.3.3-precise-amd64"))[0]
	err := statetesting.SetAgentVersion(s.State, downgradeTools.Version.Number)
	c.Assert(err, gc.IsNil)

	u := s.makeUpgrader()
	err = u.Stop()
	// If the upgrade would have triggered, we would have gotten an
	// UpgradeReadyError, since it was skipped, we get no error
	c.Check(err, gc.IsNil)
	_, err = agenttools.ReadTools(s.DataDir(), downgradeTools.Version)
	// TODO: ReadTools *should* be returning some form of errors.NotFound,
	// however, it just passes back a fmt.Errorf so we live with it
	// c.Assert(err, jc.Satisfies, errors.IsNotFound)
	c.Check(err, gc.ErrorMatches, "cannot read tools metadata in tools directory.*no such file or directory")
}

func (s *simplestreamsSuite) TestWriteMetadataNoFetch(c *gc.C) {
	toolsList := coretools.List{
		{
			Version: version.MustParseBinary("1.2.3-precise-amd64"),
			Size:    123,
			SHA256:  "abcd",
		}, {
			Version: version.MustParseBinary("2.0.1-raring-amd64"),
			Size:    456,
			SHA256:  "xyz",
		},
	}
	dir := c.MkDir()
	writer, err := filestorage.NewFileStorageWriter(dir)
	c.Assert(err, gc.IsNil)
	err = tools.MergeAndWriteMetadata(writer, toolsList, tools.DoNotWriteMirrors)
	c.Assert(err, gc.IsNil)
	metadata := ttesting.ParseMetadataFromDir(c, dir, false)
	assertMetadataMatches(c, dir, toolsList, metadata)
}

func (s *UpgraderSuite) TestChangeAgentTools(c *gc.C) {
	oldTools := &coretools.Tools{
		Version: version.MustParseBinary("1.2.3-quantal-amd64"),
	}
	stor := s.Conn.Environ.Storage()
	newTools := envtesting.PrimeTools(c, stor, s.DataDir(), version.MustParseBinary("5.4.3-precise-amd64"))
	s.PatchValue(&version.Current, newTools.Version)
	err := envtools.MergeAndWriteMetadata(stor, coretools.List{newTools}, envtools.DoNotWriteMirrors)
	c.Assert(err, gc.IsNil)
	ugErr := &upgrader.UpgradeReadyError{
		AgentName: "anAgent",
		OldTools:  oldTools.Version,
		NewTools:  newTools.Version,
		DataDir:   s.DataDir(),
	}
	err = ugErr.ChangeAgentTools()
	c.Assert(err, gc.IsNil)
	link, err := os.Readlink(agenttools.ToolsDir(s.DataDir(), "anAgent"))
	c.Assert(err, gc.IsNil)
	c.Assert(link, gc.Equals, newTools.Version.String())
}