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 *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.

	// 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 *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)
}

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) TestResolveCalledWithInitialEndpoints(c *gc.C) {
	// Test that if no hostnames exist cached we call resolve (i.e.
	// simulate the behavior right after bootstrap)

	// 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",
	)
	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",
	}
	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 %v - resolving hostnames", 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 (c *LoginCommand) cacheConnectionInfo(serverDetails envcmd.ServerFile, apiState api.Connection) (configstore.EnvironInfo, error) {
	store, err := configstore.Default()
	if err != nil {
		return nil, errors.Trace(err)
	}
	serverInfo := store.CreateInfo(c.Name)

	serverTag, err := apiState.ServerTag()
	if err != nil {
		return nil, errors.Wrap(err, errors.New("juju system too old to support login"))
	}

	connectedAddresses, err := network.ParseHostPorts(apiState.Addr())
	if err != nil {
		// Should never happen, since we've just connected with it.
		return nil, errors.Annotatef(err, "invalid API address %q", apiState.Addr())
	}
	addressConnectedTo := connectedAddresses[0]

	addrs, hosts, changed := juju.PrepareEndpointsForCaching(serverInfo, apiState.APIHostPorts(), addressConnectedTo)
	if !changed {
		logger.Infof("api addresses: %v", apiState.APIHostPorts())
		logger.Infof("address connected to: %v", addressConnectedTo)
		return nil, errors.New("no addresses returned from prepare for caching")
	}

	serverInfo.SetAPICredentials(
		configstore.APICredentials{
			User:     serverDetails.Username,
			Password: serverDetails.Password,
		})

	serverInfo.SetAPIEndpoint(configstore.APIEndpoint{
		Addresses:  addrs,
		Hostnames:  hosts,
		CACert:     serverDetails.CACert,
		ServerUUID: serverTag.Id(),
	})

	if err = serverInfo.Write(); err != nil {
		return nil, errors.Trace(err)
	}
	return serverInfo, nil
}

func (s *CacheAPIEndpointsSuite) TestResolveCalledWithInitialEndpoints(c *gc.C) {
	// Test that if no hostnames exist cached we call resolve (i.e.
	// simulate the behavior right after bootstrap)
	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",
	)
	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{})
	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 %v - resolving hostnames", 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)
}

func (s *BootstrapSuite) run(c *gc.C, test bootstrapTest) (restore gitjujutesting.Restorer) {
	// Create home with dummy provider and remove all
	// of its envtools.
	env := resetJujuHome(c, "peckham")

	// Although we're testing PrepareEndpointsForCaching interactions
	// separately in the juju package, here we just ensure it gets
	// called with the right arguments.
	prepareCalled := false
	addrConnectedTo := "localhost:17070"
	restore = gitjujutesting.PatchValue(
		&prepareEndpointsForCaching,
		func(info configstore.EnvironInfo, hps [][]network.HostPort, addr network.HostPort) (_, _ []string, _ bool) {
			prepareCalled = true
			addrs, hosts, changed := juju.PrepareEndpointsForCaching(info, hps, addr)
			// Because we're bootstrapping the addresses will always
			// change, as there's no .jenv file saved yet.
			c.Assert(changed, jc.IsTrue)
			return addrs, hosts, changed
		},
	)

	if test.version != "" {
		useVersion := strings.Replace(test.version, "%LTS%", config.LatestLtsSeries(), 1)
		origVersion := version.Current
		version.Current = version.MustParseBinary(useVersion)
		restore = restore.Add(func() {
			version.Current = origVersion
		})
	}

	if test.hostArch != "" {
		origArch := arch.HostArch
		arch.HostArch = func() string {
			return test.hostArch
		}
		restore = restore.Add(func() {
			arch.HostArch = origArch
		})
	}

	// Run command and check for uploads.
	opc, errc := cmdtesting.RunCommand(cmdtesting.NullContext(c), envcmd.Wrap(new(BootstrapCommand)), test.args...)
	// Check for remaining operations/errors.
	if test.err != "" {
		err := <-errc
		c.Assert(err, gc.NotNil)
		stripped := strings.Replace(err.Error(), "\n", "", -1)
		c.Check(stripped, gc.Matches, test.err)
		return restore
	}
	if !c.Check(<-errc, gc.IsNil) {
		return restore
	}

	opBootstrap := (<-opc).(dummy.OpBootstrap)
	c.Check(opBootstrap.Env, gc.Equals, "peckham")
	c.Check(opBootstrap.Args.Constraints, gc.DeepEquals, test.constraints)
	c.Check(opBootstrap.Args.Placement, gc.Equals, test.placement)

	opFinalizeBootstrap := (<-opc).(dummy.OpFinalizeBootstrap)
	c.Check(opFinalizeBootstrap.Env, gc.Equals, "peckham")
	c.Check(opFinalizeBootstrap.InstanceConfig.Tools, gc.NotNil)
	if test.upload != "" {
		c.Check(opFinalizeBootstrap.InstanceConfig.Tools.Version.String(), gc.Equals, test.upload)
	}

	store, err := configstore.Default()
	c.Assert(err, jc.ErrorIsNil)
	// Check a CA cert/key was generated by reloading the environment.
	env, err = environs.NewFromName("peckham", store)
	c.Assert(err, jc.ErrorIsNil)
	_, hasCert := env.Config().CACert()
	c.Check(hasCert, jc.IsTrue)
	_, hasKey := env.Config().CAPrivateKey()
	c.Check(hasKey, jc.IsTrue)
	info, err := store.ReadInfo("peckham")
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(info, gc.NotNil)
	c.Assert(prepareCalled, jc.IsTrue)
	c.Assert(info.APIEndpoint().Addresses, gc.DeepEquals, []string{addrConnectedTo})
	return restore
}