func (s *apiAddresserSuite) TestAPIAddressesPrivateFirst(c *gc.C) {
	ctlr1, err := network.ParseHostPorts("52.7.1.1:17070", "10.0.2.1:17070")
	c.Assert(err, jc.ErrorIsNil)
	ctlr2, err := network.ParseHostPorts("53.51.121.17:17070", "10.0.1.17:17070")
	c.Assert(err, jc.ErrorIsNil)
	s.fake.hostPorts = [][]network.HostPort{
		network.NewHostPorts(1, "apiaddresses"),
		ctlr1,
		ctlr2,
		network.NewHostPorts(2, "apiaddresses"),
	}
	for _, hps := range s.fake.hostPorts {
		for _, hp := range hps {
			c.Logf("%s - %#v", hp.Scope, hp)
		}
	}

	result, err := s.addresser.APIAddresses()
	c.Assert(err, jc.ErrorIsNil)

	c.Check(result.Result, gc.DeepEquals, []string{
		"apiaddresses:1",
		"10.0.2.1:17070",
		"52.7.1.1:17070",
		"10.0.1.17:17070",
		"53.51.121.17:17070",
		"apiaddresses:2",
	})
}

func (s *HostPortSuite) TestFilterUnusableHostPorts(c *gc.C) {
	// The order is preserved, but machine- and link-local addresses
	// are dropped.
	expected := append(
		network.NewHostPorts(1234,
			"localhost",
			"example.com",
			"example.org",
			"2001:db8::2",
			"example.net",
			"invalid host",
			"fd00::22",
			"2001:db8::1",
			"0.1.2.0",
			"2001:db8::1",
			"localhost",
			"10.0.0.1",
			"fc00::1",
			"172.16.0.1",
			"8.8.8.8",
			"7.8.8.8",
		),
		network.NewHostPorts(9999,
			"10.0.0.1",
			"2001:db8::1", // public
		)...,
	)

	result := network.FilterUnusableHostPorts(s.makeHostPorts())
	c.Assert(result, gc.HasLen, len(expected))
	c.Assert(result, jc.DeepEquals, expected)
}

func (s *publishSuite) TestPublisherSetsAPIHostPortsOnce(c *gc.C) {
	var mock mockAPIHostPortsSetter
	statePublish := newPublisher(&mock)

	hostPorts1 := network.NewHostPorts(1234, "testing1.invalid", "127.0.0.1")
	hostPorts2 := network.NewHostPorts(1234, "testing2.invalid", "127.0.0.2")

	// statePublish.publishAPIServers should not update state a second time.
	apiServers := [][]network.HostPort{hostPorts1}
	for i := 0; i < 2; i++ {
		err := statePublish.publishAPIServers(apiServers, nil)
		c.Assert(err, jc.ErrorIsNil)
	}

	c.Assert(mock.calls, gc.Equals, 1)
	c.Assert(mock.apiHostPorts, gc.DeepEquals, apiServers)

	apiServers = append(apiServers, hostPorts2)
	for i := 0; i < 2; i++ {
		err := statePublish.publishAPIServers(apiServers, nil)
		c.Assert(err, jc.ErrorIsNil)
	}
	c.Assert(mock.calls, gc.Equals, 2)
	c.Assert(mock.apiHostPorts, gc.DeepEquals, apiServers)
}

func (*HostPortSuite) TestParseHostPortsSuccess(c *gc.C) {
	for i, test := range []struct {
		args   []string
		expect []network.HostPort
	}{{
		args:   nil,
		expect: []network.HostPort{},
	}, {
		args:   []string{"1.2.3.4:42"},
		expect: network.NewHostPorts(42, "1.2.3.4"),
	}, {
		args:   []string{"[fc00::1]:1234"},
		expect: network.NewHostPorts(1234, "fc00::1"),
	}, {
		args: []string{"[fc00::1]:1234", "127.0.0.1:4321", "example.com:42"},
		expect: []network.HostPort{
			{network.NewAddress("fc00::1"), 1234},
			{network.NewAddress("127.0.0.1"), 4321},
			{network.NewAddress("example.com"), 42},
		},
	}} {
		c.Logf("test %d: args %v", i, test.args)
		hps, err := network.ParseHostPorts(test.args...)
		c.Check(err, jc.ErrorIsNil)
		c.Check(hps, jc.DeepEquals, test.expect)
	}
}

func (s *stateAddresserSuite) SetUpTest(c *gc.C) {
	s.addresser = common.NewStateAddresser(fakeAddresses{
		hostPorts: [][]network.HostPort{
			network.NewHostPorts(1, "apiaddresses"),
			network.NewHostPorts(2, "apiaddresses"),
		},
	})
}

func (s *serverSuite) TestAPIServerCanListenOnBothIPv4AndIPv6(c *gc.C) {
	err := s.State.SetAPIHostPorts(nil)
	c.Assert(err, jc.ErrorIsNil)

	// Start our own instance of the server listening on
	// both IPv4 and IPv6 localhost addresses and an ephemeral port.
	listener, err := net.Listen("tcp", ":0")
	c.Assert(err, jc.ErrorIsNil)
	srv, err := apiserver.NewServer(s.State, listener, apiserver.ServerConfig{
		Cert: []byte(coretesting.ServerCert),
		Key:  []byte(coretesting.ServerKey),
		Tag:  names.NewMachineTag("0"),
	})
	c.Assert(err, jc.ErrorIsNil)
	defer srv.Stop()

	port := srv.Addr().Port
	portString := fmt.Sprintf("%d", port)

	machine, password := s.Factory.MakeMachineReturningPassword(
		c, &factory.MachineParams{Nonce: "fake_nonce"})

	// Now connect twice - using IPv4 and IPv6 endpoints.
	apiInfo := &api.Info{
		Tag:        machine.Tag(),
		Password:   password,
		Nonce:      "fake_nonce",
		Addrs:      []string{net.JoinHostPort("127.0.0.1", portString)},
		CACert:     coretesting.CACert,
		EnvironTag: s.State.EnvironTag(),
	}
	ipv4State, err := api.Open(apiInfo, fastDialOpts)
	c.Assert(err, jc.ErrorIsNil)
	defer ipv4State.Close()
	c.Assert(ipv4State.Addr(), gc.Equals, net.JoinHostPort("127.0.0.1", portString))
	c.Assert(ipv4State.APIHostPorts(), jc.DeepEquals, [][]network.HostPort{
		network.NewHostPorts(port, "127.0.0.1"),
	})

	_, err = ipv4State.Machiner().Machine(machine.MachineTag())
	c.Assert(err, jc.ErrorIsNil)

	apiInfo.Addrs = []string{net.JoinHostPort("::1", portString)}
	ipv6State, err := api.Open(apiInfo, fastDialOpts)
	c.Assert(err, jc.ErrorIsNil)
	defer ipv6State.Close()
	c.Assert(ipv6State.Addr(), gc.Equals, net.JoinHostPort("::1", portString))
	c.Assert(ipv6State.APIHostPorts(), jc.DeepEquals, [][]network.HostPort{
		network.NewHostPorts(port, "::1"),
	})

	_, err = ipv6State.Machiner().Machine(machine.MachineTag())
	c.Assert(err, jc.ErrorIsNil)
}

func (sb *stubBackend) APIHostPorts() ([][]network.HostPort, error) {
	sb.MethodCall(sb, "APIHostPorts")
	if err := sb.NextErr(); err != nil {
		return nil, err
	}
	hps := [][]network.HostPort{
		network.NewHostPorts(1234, "0.1.2.3"),
		network.NewHostPorts(1234, "0.1.2.4"),
		network.NewHostPorts(1234, "0.1.2.5"),
	}
	return hps, nil
}

func (s *CacheAPIEndpointsSuite) TestAfterResolvingUnchangedAddressesNotCached(c *gc.C) {
	// Test that if new endpoints hostnames are different than the
	// cached hostnames, but after resolving the addresses match the
	// cached addresses, the cache is not changed.

	// Because Hostnames are sorted before caching, reordering them
	// will simulate they have changed.
	unsortedHPs := network.NewHostPorts(1234,
		"ipv4.example.com",
		"8.8.8.8",
		"ipv6.example.com",
		"10.0.0.1",
	)
	strUnsorted := network.HostPortsToStrings(unsortedHPs)
	sortedHPs := network.NewHostPorts(1234,
		"8.8.8.8",
		"ipv4.example.com",
		"ipv6.example.com",
		"10.0.0.1",
	)
	resolvedHPs := network.NewHostPorts(1234,
		"0.1.2.1", // from ipv4.example.com
		"8.8.8.8",
		"10.0.0.1",
		"fc00::2", // from ipv6.example.com
	)
	strResolved := network.HostPortsToStrings(resolvedHPs)
	controllerDetails := jujuclient.ControllerDetails{
		ControllerUUID:         fakeUUID,
		CACert:                 "certificate",
		UnresolvedAPIEndpoints: strUnsorted,
		APIEndpoints:           strResolved,
	}
	err := s.ControllerStore.AddController("controller-name", controllerDetails)
	c.Assert(err, jc.ErrorIsNil)

	addrs, hosts, changed := juju.PrepareEndpointsForCaching(
		controllerDetails, [][]network.HostPort{unsortedHPs},
	)
	c.Assert(addrs, gc.IsNil)
	c.Assert(hosts, gc.IsNil)
	c.Assert(changed, jc.IsFalse)
	c.Assert(s.resolveNumCalls, gc.Equals, 1)
	c.Assert(s.numResolved, gc.Equals, 2)
	expectLog := fmt.Sprintf("DEBUG juju.juju API hostnames changed from %v to %v - resolving hostnames", unsortedHPs, sortedHPs)
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
	expectLog = "DEBUG juju.juju API addresses unchanged"
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
}

func (s *CacheAPIEndpointsSuite) TestResolveCalledWithChangedHostnames(c *gc.C) {
	// Test that if new endpoints hostnames are different than the
	// cached hostnames DNS resolution happens and we compare resolved
	// addresses.
	// Because Hostnames are sorted before caching, reordering them
	// will simulate they have changed.
	unsortedHPs := network.NewHostPorts(1234,
		"ipv4.example.com",
		"8.8.8.8",
		"ipv6.example.com",
		"10.0.0.1",
	)
	strUnsorted := network.HostPortsToStrings(unsortedHPs)
	sortedHPs := network.NewHostPorts(1234,
		"8.8.8.8",
		"ipv4.example.com",
		"ipv6.example.com",
		"10.0.0.1",
	)
	strSorted := network.HostPortsToStrings(sortedHPs)
	resolvedHPs := network.NewHostPorts(1234,
		"0.1.2.1", // from ipv4.example.com
		"8.8.8.8",
		"10.0.0.1",
		"fc00::2", // from ipv6.example.com
	)
	strResolved := network.HostPortsToStrings(resolvedHPs)
	controllerDetails := jujuclient.ControllerDetails{
		ControllerUUID:         fakeUUID,
		CACert:                 "certificate",
		UnresolvedAPIEndpoints: strUnsorted,
	}
	err := s.ControllerStore.AddController("controller-name", controllerDetails)
	c.Assert(err, jc.ErrorIsNil)

	addrs, hosts, changed := juju.PrepareEndpointsForCaching(
		controllerDetails, [][]network.HostPort{unsortedHPs},
	)
	c.Assert(addrs, jc.DeepEquals, strResolved)
	c.Assert(hosts, jc.DeepEquals, strSorted)
	c.Assert(changed, jc.IsTrue)
	c.Assert(s.resolveNumCalls, gc.Equals, 1)
	c.Assert(s.numResolved, gc.Equals, 2)
	expectLog := fmt.Sprintf("DEBUG juju.juju API hostnames changed from %v to %v - resolving hostnames", unsortedHPs, sortedHPs)
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
	expectLog = fmt.Sprintf("INFO juju.juju new API addresses to cache %v", resolvedHPs)
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
}

func (s *HostPortSuite) TestDropDuplicatedHostPorts(c *gc.C) {
	hps := s.makeHostPorts()
	noDups := network.DropDuplicatedHostPorts(hps)
	c.Assert(noDups, gc.Not(gc.HasLen), len(hps))
	c.Assert(noDups, jc.DeepEquals, network.NewHostPorts(1234,
		"127.0.0.1",
		"localhost",
		"example.com",
		"127.0.1.1",
		"example.org",
		"2001:db8::2",
		"169.254.1.1",
		"example.net",
		"invalid host",
		"fd00::22",
		"2001:db8::1",
		"169.254.1.2",
		"ff01::22",
		"0.1.2.0",
		"10.0.0.1",
		"::1",
		"fc00::1",
		"fe80::2",
		"172.16.0.1",
		"8.8.8.8",
		"7.8.8.8",
	))
}

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")
}

// testNamespace starts a worker and ensures that
// the rsyslog config file has the expected filename,
// and the appropriate log dir is used.
func (s *RsyslogSuite) testNamespace(c *gc.C, st *api.State, tag names.Tag, namespace, expectedFilename, expectedLogDir string) {
	restarted := make(chan struct{}, 2) // once for create, once for teardown
	s.PatchValue(rsyslog.RestartRsyslog, func() error {
		restarted <- struct{}{}
		return nil
	})

	err := os.MkdirAll(expectedLogDir, 0755)
	c.Assert(err, jc.ErrorIsNil)
	worker, err := rsyslog.NewRsyslogConfigWorker(st.Rsyslog(), rsyslog.RsyslogModeAccumulate, tag, namespace, []string{"0.1.2.3"})
	c.Assert(err, jc.ErrorIsNil)
	defer func() { c.Assert(worker.Wait(), gc.IsNil) }()
	defer worker.Kill()

	// change the API HostPorts to trigger an rsyslog restart
	newHostPorts := network.NewHostPorts(6541, "127.0.0.1")
	err = s.State.SetAPIHostPorts([][]network.HostPort{newHostPorts})
	c.Assert(err, jc.ErrorIsNil)

	// Wait for rsyslog to be restarted, so we can check to see
	// what the name of the config file is.
	waitForRestart(c, restarted)

	// Ensure that ca-cert.pem gets written to the expected log dir.
	waitForFile(c, filepath.Join(expectedLogDir, "ca-cert.pem"))

	dir, err := os.Open(*rsyslog.RsyslogConfDir)
	c.Assert(err, jc.ErrorIsNil)
	names, err := dir.Readdirnames(-1)
	dir.Close()
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(names, gc.HasLen, 1)
	c.Assert(names[0], gc.Equals, expectedFilename)
}

func (s *CacheAPIEndpointsSuite) TestResolveSkippedWhenHostnamesUnchanged(c *gc.C) {
	// Test that if new endpoints hostnames are the same as the
	// cached, no DNS resolution happens (i.e. we don't resolve on
	// every connection, but as needed).
	info := s.store.CreateInfo("env-name")
	hps := network.NewHostPorts(1234,
		"8.8.8.8",
		"example.com",
		"10.0.0.1",
	)
	info.SetAPIEndpoint(configstore.APIEndpoint{
		Hostnames: network.HostPortsToStrings(hps),
	})
	err := info.Write()
	c.Assert(err, jc.ErrorIsNil)

	addrs, hosts, changed := juju.PrepareEndpointsForCaching(
		info, [][]network.HostPort{hps}, network.HostPort{},
	)
	c.Assert(addrs, gc.IsNil)
	c.Assert(hosts, gc.IsNil)
	c.Assert(changed, jc.IsFalse)
	c.Assert(s.resolveNumCalls, gc.Equals, 0)
	c.Assert(
		c.GetTestLog(),
		jc.Contains,
		"DEBUG juju.api API hostnames unchanged - not resolving",
	)
}

func (s *workerSuite) TestStateServersArePublished(c *gc.C) {
	DoTestForIPv4AndIPv6(func(ipVersion TestIPVersion) {
		publishCh := make(chan [][]network.HostPort)
		publish := func(apiServers [][]network.HostPort, instanceIds []instance.Id) error {
			publishCh <- apiServers
			return nil
		}

		st := NewFakeState()
		InitState(c, st, 3, ipVersion)
		w := newWorker(st, PublisherFunc(publish))
		defer func() {
			c.Check(worker.Stop(w), gc.IsNil)
		}()
		select {
		case servers := <-publishCh:
			AssertAPIHostPorts(c, servers, ExpectedAPIHostPorts(3, ipVersion))
		case <-time.After(coretesting.LongWait):
			c.Fatalf("timed out waiting for publish")
		}

		// Change one of the servers' API addresses and check that it's published.
		var newMachine10APIHostPorts []network.HostPort
		newMachine10APIHostPorts = network.NewHostPorts(apiPort, ipVersion.extraHost)
		st.machine("10").setAPIHostPorts(newMachine10APIHostPorts)
		select {
		case servers := <-publishCh:
			expected := ExpectedAPIHostPorts(3, ipVersion)
			expected[0] = newMachine10APIHostPorts
			AssertAPIHostPorts(c, servers, expected)
		case <-time.After(coretesting.LongWait):
			c.Fatalf("timed out waiting for publish")
		}
	})
}

func (s *APIAddresserTests) TestWatchAPIHostPorts(c *gc.C) {
	expectServerAddrs := [][]network.HostPort{
		network.NewHostPorts(1234, "0.1.2.3"),
	}
	err := s.state.SetAPIHostPorts(expectServerAddrs)
	c.Assert(err, jc.ErrorIsNil)

	w, err := s.facade.WatchAPIHostPorts()
	c.Assert(err, jc.ErrorIsNil)
	defer statetesting.AssertStop(c, w)

	wc := statetesting.NewNotifyWatcherC(c, s.state, w)

	// Initial event.
	wc.AssertOneChange()

	// Change the state addresses and check that we get a notification
	expectServerAddrs[0][0].Value = "0.1.99.99"

	err = s.state.SetAPIHostPorts(expectServerAddrs)
	c.Assert(err, jc.ErrorIsNil)

	wc.AssertOneChange()

	statetesting.AssertStop(c, w)
	wc.AssertClosed()
}

func (s *APIAddressUpdaterSuite) TestAddressChange(c *gc.C) {
	setter := &apiAddressSetter{servers: make(chan [][]network.HostPort, 1)}
	st, _ := s.OpenAPIAsNewMachine(c, state.JobHostUnits)
	worker, err := apiaddressupdater.NewAPIAddressUpdater(st.Machiner(), setter)
	c.Assert(err, jc.ErrorIsNil)
	defer func() { c.Assert(worker.Wait(), gc.IsNil) }()
	defer worker.Kill()
	s.BackingState.StartSync()
	updatedServers := [][]network.HostPort{
		network.NewHostPorts(1234, "localhost", "127.0.0.1"),
	}
	// SetAPIHostPorts should be called with the initial value (empty),
	// and then the updated value.
	select {
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timed out waiting for SetAPIHostPorts to be called initially")
	case servers := <-setter.servers:
		c.Assert(servers, gc.HasLen, 0)
	}
	err = s.State.SetAPIHostPorts(updatedServers)
	c.Assert(err, jc.ErrorIsNil)
	s.BackingState.StartSync()
	select {
	case <-time.After(coretesting.LongWait):
		c.Fatalf("timed out waiting for SetAPIHostPorts to be called after update")
	case servers := <-setter.servers:
		c.Assert(servers, gc.DeepEquals, updatedServers)
	}
}

func (*HostPortSuite) makeHostPorts() []network.HostPort {
	return network.NewHostPorts(1234,
		"127.0.0.1",    // machine-local
		"localhost",    // hostname
		"example.com",  // hostname
		"127.0.1.1",    // machine-local
		"example.org",  // hostname
		"2001:db8::2",  // public
		"169.254.1.1",  // link-local
		"example.net",  // hostname
		"invalid host", // hostname
		"fd00::22",     // cloud-local
		"127.0.0.1",    // machine-local
		"2001:db8::1",  // public
		"169.254.1.2",  // link-local
		"ff01::22",     // link-local
		"0.1.2.0",      // public
		"2001:db8::1",  // public
		"localhost",    // hostname
		"10.0.0.1",     // cloud-local
		"::1",          // machine-local
		"fc00::1",      // cloud-local
		"fe80::2",      // link-local
		"172.16.0.1",   // cloud-local
		"::1",          // machine-local
		"8.8.8.8",      // public
		"7.8.8.8",      // public
	)
}

func (s *CacheAPIEndpointsSuite) TestResolveSkippedWhenHostnamesUnchanged(c *gc.C) {
	// Test that if new endpoints hostnames are the same as the
	// cached, no DNS resolution happens (i.e. we don't resolve on
	// every connection, but as needed).
	hps := network.NewHostPorts(1234,
		"8.8.8.8",
		"example.com",
		"10.0.0.1",
	)
	controllerDetails := jujuclient.ControllerDetails{
		ControllerUUID:         fakeUUID,
		CACert:                 "certificate",
		UnresolvedAPIEndpoints: network.HostPortsToStrings(hps),
	}
	err := s.ControllerStore.AddController("controller-name", controllerDetails)
	c.Assert(err, jc.ErrorIsNil)

	addrs, hosts, changed := juju.PrepareEndpointsForCaching(
		controllerDetails, [][]network.HostPort{hps},
	)
	c.Assert(addrs, gc.IsNil)
	c.Assert(hosts, gc.IsNil)
	c.Assert(changed, jc.IsFalse)
	c.Assert(s.resolveNumCalls, gc.Equals, 0)
	c.Assert(
		c.GetTestLog(),
		jc.Contains,
		"DEBUG juju.juju API hostnames unchanged - not resolving",
	)
}

func (s *CacheAPIEndpointsSuite) TestAfterResolvingUnchangedAddressesNotCached(c *gc.C) {
	// Test that if new endpoints hostnames are different than the
	// cached hostnames, but after resolving the addresses match the
	// cached addresses, the cache is not changed.
	info := s.store.CreateInfo("env-name")
	// Because Hostnames are sorted before caching, reordering them
	// will simulate they have changed.
	unsortedHPs := network.NewHostPorts(1234,
		"ipv4.example.com",
		"8.8.8.8",
		"ipv6.example.com",
		"10.0.0.1",
	)
	strUnsorted := network.HostPortsToStrings(unsortedHPs)
	sortedHPs := network.NewHostPorts(1234,
		"8.8.8.8",
		"ipv4.example.com",
		"ipv6.example.com",
		"10.0.0.1",
	)
	resolvedHPs := network.NewHostPorts(1234,
		"0.1.2.1", // from ipv4.example.com
		"8.8.8.8",
		"10.0.0.1",
		"fc00::2", // from ipv6.example.com
	)
	strResolved := network.HostPortsToStrings(resolvedHPs)
	info.SetAPIEndpoint(configstore.APIEndpoint{
		Hostnames: strUnsorted,
		Addresses: strResolved,
	})
	err := info.Write()
	c.Assert(err, jc.ErrorIsNil)

	addrs, hosts, changed := juju.PrepareEndpointsForCaching(
		info, [][]network.HostPort{unsortedHPs}, network.HostPort{},
	)
	c.Assert(addrs, gc.IsNil)
	c.Assert(hosts, gc.IsNil)
	c.Assert(changed, jc.IsFalse)
	c.Assert(s.resolveNumCalls, gc.Equals, 1)
	c.Assert(s.numResolved, gc.Equals, 2)
	expectLog := fmt.Sprintf("DEBUG juju.api API hostnames changed from %v to %v - resolving hostnames", unsortedHPs, sortedHPs)
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
	expectLog = "DEBUG juju.api API addresses unchanged"
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
}

func (s *CacheAPIEndpointsSuite) TestResolveCalledWithChangedHostnames(c *gc.C) {
	// Test that if new endpoints hostnames are different than the
	// cached hostnames DNS resolution happens and we compare resolved
	// addresses.
	info := s.store.CreateInfo("env-name")
	// Because Hostnames are sorted before caching, reordering them
	// will simulate they have changed.
	unsortedHPs := network.NewHostPorts(1234,
		"ipv4.example.com",
		"8.8.8.8",
		"ipv6.example.com",
		"10.0.0.1",
	)
	strUnsorted := network.HostPortsToStrings(unsortedHPs)
	sortedHPs := network.NewHostPorts(1234,
		"8.8.8.8",
		"ipv4.example.com",
		"ipv6.example.com",
		"10.0.0.1",
	)
	strSorted := network.HostPortsToStrings(sortedHPs)
	resolvedHPs := network.NewHostPorts(1234,
		"0.1.2.1", // from ipv4.example.com
		"8.8.8.8",
		"10.0.0.1",
		"fc00::2", // from ipv6.example.com
	)
	strResolved := network.HostPortsToStrings(resolvedHPs)
	info.SetAPIEndpoint(configstore.APIEndpoint{
		Hostnames: strUnsorted,
	})
	err := info.Write()
	c.Assert(err, jc.ErrorIsNil)

	addrs, hosts, changed := juju.PrepareEndpointsForCaching(
		info, [][]network.HostPort{unsortedHPs}, network.HostPort{},
	)
	c.Assert(addrs, jc.DeepEquals, strResolved)
	c.Assert(hosts, jc.DeepEquals, strSorted)
	c.Assert(changed, jc.IsTrue)
	c.Assert(s.resolveNumCalls, gc.Equals, 1)
	c.Assert(s.numResolved, gc.Equals, 2)
	expectLog := fmt.Sprintf("DEBUG juju.api API hostnames changed from %v to %v - resolving hostnames", unsortedHPs, sortedHPs)
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
	expectLog = fmt.Sprintf("INFO juju.api new API addresses to cache %v", resolvedHPs)
	c.Assert(c.GetTestLog(), jc.Contains, expectLog)
}