func createContainer(c *gc.C, manager container.Manager, machineId string) instance.Instance {
	machineNonce := "fake-nonce"
	stateInfo := jujutesting.FakeStateInfo(machineId)
	apiInfo := jujutesting.FakeAPIInfo(machineId)
	instanceConfig, err := instancecfg.NewInstanceConfig(machineId, machineNonce, imagemetadata.ReleasedStream, "quantal", "", true, stateInfo, apiInfo)
	c.Assert(err, jc.ErrorIsNil)
	network := container.BridgeNetworkConfig("virbr0", 0, nil)

	err = instanceConfig.SetTools(tools.List{
		&tools.Tools{
			Version: version.MustParseBinary("2.3.4-foo-bar"),
			URL:     "http://tools.testing.invalid/2.3.4-foo-bar.tgz",
		},
	})
	c.Assert(err, jc.ErrorIsNil)
	environConfig := dummyConfig(c)
	err = instancecfg.FinishInstanceConfig(instanceConfig, environConfig)
	c.Assert(err, jc.ErrorIsNil)
	callback := func(settableStatus status.Status, info string, data map[string]interface{}) error { return nil }
	inst, hardware, err := manager.CreateContainer(instanceConfig, "precise", network, nil, callback)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(hardware, gc.NotNil)
	expected := fmt.Sprintf("arch=%s cpu-cores=1 mem=512M root-disk=8192M", arch.HostArch())
	c.Assert(hardware.String(), gc.Equals, expected)
	return inst
}

func (*NetworkSuite) TestGenerateNetworkConfig(c *gc.C) {
	for _, test := range []struct {
		config *container.NetworkConfig
		net    string
		link   string
	}{{
		config: nil,
		net:    "veth",
		link:   "lxcbr0",
	}, {
		config: lxc.DefaultNetworkConfig(),
		net:    "veth",
		link:   "lxcbr0",
	}, {
		config: container.BridgeNetworkConfig("foo"),
		net:    "veth",
		link:   "foo",
	}, {
		config: container.PhysicalNetworkConfig("foo"),
		net:    "phys",
		link:   "foo",
	}} {
		config := lxc.GenerateNetworkConfig(test.config)
		c.Assert(config, jc.Contains, fmt.Sprintf("lxc.network.type = %s\n", test.net))
		c.Assert(config, jc.Contains, fmt.Sprintf("lxc.network.link = %s\n", test.link))
	}
}

func (s *UserDataSuite) TestCloudInitUserDataFallbackConfigWithContainerHostname(c *gc.C) {
	instanceConfig, err := containertesting.MockMachineConfig("1/lxd/0")
	instanceConfig.MachineContainerHostname = "lxdhostname"
	c.Assert(err, jc.ErrorIsNil)
	networkConfig := container.BridgeNetworkConfig("foo", 0, nil)
	data, err := containerinit.CloudInitUserData(instanceConfig, networkConfig)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(data, gc.NotNil)

	linesToMatch := CloudInitDataExcludingOutputSection(string(data))

	expected := fmt.Sprintf(s.expectedFallbackUserData, s.networkInterfacesFile, s.systemNetworkInterfacesFile)
	var expectedLinesToMatch []string

	for _, line := range strings.Split(expected, "\n") {
		if strings.HasPrefix(line, "runcmd:") {
			break
		}
		expectedLinesToMatch = append(expectedLinesToMatch, line)
	}

	expectedLinesToMatch = append(expectedLinesToMatch, "hostname: lxdhostname")
	expectedLinesToMatch = append(expectedLinesToMatch, "manage_etc_hosts: true")

	c.Assert(strings.Join(linesToMatch, "\n")+"\n", gc.Equals, strings.Join(expectedLinesToMatch, "\n")+"\n")
}

// CreateContainerTest tries to create a container and returns any errors encountered along the
// way
func CreateContainerTest(c *gc.C, manager container.Manager, machineId string) (instance.Instance, error) {
	instanceConfig, err := MockMachineConfig(machineId)
	if err != nil {
		return nil, errors.Trace(err)
	}

	envConfig, err := config.New(config.NoDefaults, dummy.SampleConfig())
	if err != nil {
		return nil, errors.Trace(err)
	}
	instanceConfig.Config = envConfig

	network := container.BridgeNetworkConfig("nic42", 0, nil)
	storage := &container.StorageConfig{}

	callback := func(settableStatus status.Status, info string, data map[string]interface{}) error { return nil }
	inst, hardware, err := manager.CreateContainer(instanceConfig, "quantal", network, storage, callback)

	if err != nil {
		return nil, errors.Trace(err)
	}
	if hardware == nil {
		return nil, errors.New("nil hardware characteristics")
	}
	if hardware.String() == "" {
		return nil, errors.New("empty hardware characteristics")
	}
	return inst, nil

}

func (s *UserDataSuite) TestNewCloudInitConfigWithNetworksNoConfig(c *gc.C) {
	netConfig := container.BridgeNetworkConfig("foo", 0, nil)
	cloudConf, err := containerinit.NewCloudInitConfigWithNetworks("quantal", netConfig)
	c.Assert(err, jc.ErrorIsNil)
	expected := "#cloud-config\n{}\n"
	assertUserData(c, cloudConf, expected)
}

func (s *LxcSuite) TestCreateContainerWithBlockStorage(c *gc.C) {
	err := os.Remove(s.RestartDir)
	c.Assert(err, jc.ErrorIsNil)

	manager := s.makeManager(c, "test")
	machineConfig, err := containertesting.MockMachineConfig("1/lxc/0")
	c.Assert(err, jc.ErrorIsNil)
	storageConfig := &container.StorageConfig{AllowMount: true}
	networkConfig := container.BridgeNetworkConfig("nic42", 4321, nil)
	instance := containertesting.CreateContainerWithMachineAndNetworkAndStorageConfig(c, manager, machineConfig, networkConfig, storageConfig)
	name := string(instance.Id())
	autostartLink := lxc.RestartSymlink(name)
	config, err := ioutil.ReadFile(lxc.ContainerConfigFilename(name))
	c.Assert(err, jc.ErrorIsNil)
	expected := fmt.Sprintf(`
# network config
# interface "eth0"
lxc.network.type = veth
lxc.network.link = nic42
lxc.network.flags = up
lxc.network.mtu = 4321

lxc.start.auto = 1
lxc.mount.entry = %s var/log/juju none defaults,bind 0 0

lxc.aa_profile = lxc-container-default-with-mounting
lxc.cgroup.devices.allow = b 7:* rwm
lxc.cgroup.devices.allow = c 10:237 rwm
`, s.logDir)
	c.Assert(string(config), gc.Equals, expected)
	c.Assert(autostartLink, jc.DoesNotExist)
}

func (s *UserDataSuite) TestGenerateNetworkConfig(c *gc.C) {
	data, err := containerinit.GenerateNetworkConfig(nil)
	c.Assert(err, gc.ErrorMatches, "missing container network config")
	c.Assert(data, gc.Equals, "")

	netConfig := container.BridgeNetworkConfig("foo", 0, nil)
	data, err = containerinit.GenerateNetworkConfig(netConfig)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(data, gc.Equals, s.expectedFallbackConfig)

	// Test with all interface types.
	netConfig = container.BridgeNetworkConfig("foo", 0, s.fakeInterfaces)
	data, err = containerinit.GenerateNetworkConfig(netConfig)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(data, gc.Equals, s.expectedSampleConfig)
}

func (s *UserDataSuite) TestGenerateNetworkConfig(c *gc.C) {
	// No config or no interfaces - no error, but also noting to generate.
	data, err := containerinit.GenerateNetworkConfig(nil)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(data, gc.HasLen, 0)
	netConfig := container.BridgeNetworkConfig("foo", 0, nil)
	data, err = containerinit.GenerateNetworkConfig(netConfig)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(data, gc.HasLen, 0)

	// Test with all interface types.
	netConfig = container.BridgeNetworkConfig("foo", 0, s.fakeInterfaces)
	data, err = containerinit.GenerateNetworkConfig(netConfig)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(data, gc.Equals, s.expectedNetConfig)
}

func (s *UserDataSuite) TestNewCloudInitConfigWithNetworksFallbackConfig(c *gc.C) {
	netConfig := container.BridgeNetworkConfig("foo", 0, nil)
	cloudConf, err := containerinit.NewCloudInitConfigWithNetworks("quantal", netConfig)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(cloudConf, gc.NotNil)
	expected := fmt.Sprintf(s.expectedFallbackUserData, s.networkInterfacesFile, s.systemNetworkInterfacesFile)
	assertUserData(c, cloudConf, expected)
}

func CreateContainerWithMachineConfig(
	c *gc.C,
	manager container.Manager,
	instanceConfig *instancecfg.InstanceConfig,
) instance.Instance {

	networkConfig := container.BridgeNetworkConfig("nic42", 0, nil)
	storageConfig := &container.StorageConfig{}
	return CreateContainerWithMachineAndNetworkAndStorageConfig(c, manager, instanceConfig, networkConfig, storageConfig)
}

func (s *UserDataSuite) TestCloudInitUserData(c *gc.C) {
	instanceConfig, err := containertesting.MockMachineConfig("1/lxc/0")
	c.Assert(err, jc.ErrorIsNil)
	networkConfig := container.BridgeNetworkConfig("foo", 0, nil)
	data, err := containerinit.CloudInitUserData(instanceConfig, networkConfig)
	c.Assert(err, jc.ErrorIsNil)
	// No need to test the exact contents here, as they are already
	// tested separately.
	c.Assert(string(data), jc.HasPrefix, "#cloud-config\n")
}

func (s *KVMSuite) createRunningContainer(c *gc.C, name string) kvm.Container {
	kvmContainer := s.ContainerFactory.New(name)
	network := container.BridgeNetworkConfig("testbr0")
	c.Assert(kvmContainer.Start(kvm.StartParams{
		Series:       "quantal",
		Arch:         version.Current.Arch,
		UserDataFile: "userdata.txt",
		Network:      network}), gc.IsNil)
	return kvmContainer
}

func CreateContainerWithMachineConfig(
	c *gc.C,
	manager container.Manager,
	machineConfig *cloudinit.MachineConfig,
) instance.Instance {

	network := container.BridgeNetworkConfig("nic42")
	inst, hardware, err := manager.CreateContainer(machineConfig, "quantal", network)
	c.Assert(err, gc.IsNil)
	c.Assert(hardware, gc.NotNil)
	c.Assert(hardware.String(), gc.Not(gc.Equals), "")
	return inst
}

func (s *UserDataSuite) TestCloudInitUserDataFallbackConfig(c *gc.C) {
	instanceConfig, err := containertesting.MockMachineConfig("1/lxd/0")
	c.Assert(err, jc.ErrorIsNil)
	networkConfig := container.BridgeNetworkConfig("foo", 0, nil)
	data, err := containerinit.CloudInitUserData(instanceConfig, networkConfig)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(data, gc.NotNil)

	// Extract the "#cloud-config" header and all lines between
	// from the "bootcmd" section up to (but not including) the
	// "output" sections to match against expected. But we cannot
	// possibly handle all the /other/ output that may be added by
	// CloudInitUserData() in the future, so we also truncate at
	// the first runcmd which now happens to include the runcmd's
	// added for raising the network interfaces captured in
	// expectedFallbackUserData. However, the other tests above do
	// check for that output.

	var linesToMatch []string
	seenBootcmd := false
	for _, line := range strings.Split(string(data), "\n") {
		if strings.HasPrefix(line, "#cloud-config") {
			linesToMatch = append(linesToMatch, line)
			continue
		}

		if strings.HasPrefix(line, "bootcmd:") {
			seenBootcmd = true
		}

		if strings.HasPrefix(line, "output:") && seenBootcmd {
			break
		}

		if seenBootcmd {
			linesToMatch = append(linesToMatch, line)
		}
	}
	expected := fmt.Sprintf(s.expectedFallbackUserData, s.networkInterfacesFile, s.systemNetworkInterfacesFile)

	var expectedLinesToMatch []string

	for _, line := range strings.Split(expected, "\n") {
		if strings.HasPrefix(line, "runcmd:") {
			break
		}
		expectedLinesToMatch = append(expectedLinesToMatch, line)
	}

	c.Assert(strings.Join(linesToMatch, "\n")+"\n", gc.Equals, strings.Join(expectedLinesToMatch, "\n")+"\n")
}

func (s *LxcSuite) createTemplate(c *gc.C) golxc.Container {
	name := "juju-quantal-lxc-template"
	ch := s.ensureTemplateStopped(name)
	defer func() { <-ch }()
	network := container.BridgeNetworkConfig("nic42", 4321, nil)
	authorizedKeys := "authorized keys list"
	aptProxy := proxy.Settings{}
	aptMirror := "http://my.archive.ubuntu.com/ubuntu"
	callback := func(containerStatus status.Status, info string, data map[string]interface{}) error { return nil }
	template, err := lxc.EnsureCloneTemplate(
		"ext4",
		"quantal",
		network,
		authorizedKeys,
		aptProxy,
		aptMirror,
		true,
		true,
		&containertesting.MockURLGetter{},
		false,
		callback,
	)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(template.Name(), gc.Equals, name)

	createEvent := <-s.events
	c.Assert(createEvent.Action, gc.Equals, mock.Created)
	c.Assert(createEvent.InstanceId, gc.Equals, name)
	argsSet := set.NewStrings(createEvent.TemplateArgs...)
	c.Assert(argsSet.Contains("imageURL"), jc.IsTrue)
	s.AssertEvent(c, <-s.events, mock.Started, name)
	s.AssertEvent(c, <-s.events, mock.Stopped, name)

	autostartLink := lxc.RestartSymlink(name)
	config, err := ioutil.ReadFile(lxc.ContainerConfigFilename(name))
	c.Assert(err, jc.ErrorIsNil)
	expected := `
# network config
# interface "eth0"
lxc.network.type = veth
lxc.network.link = nic42
lxc.network.flags = up
lxc.network.mtu = 4321

`
	// NOTE: no autostart, no mounting the log dir
	c.Assert(string(config), gc.Equals, expected)
	c.Assert(autostartLink, jc.DoesNotExist)

	return template
}

// StartInstance is specified in the Broker interface.
func (broker *kvmBroker) StartInstance(args environs.StartInstanceParams) (instance.Instance, *instance.HardwareCharacteristics, []network.Info, error) {
	if args.MachineConfig.HasNetworks() {
		return nil, nil, nil, fmt.Errorf("starting kvm containers with networks is not supported yet.")
	}
	// TODO: refactor common code out of the container brokers.
	machineId := args.MachineConfig.MachineId
	kvmLogger.Infof("starting kvm container for machineId: %s", machineId)

	// TODO: Default to using the host network until we can configure.  Yes,
	// this is using the LxcBridge value, we should put it in the api call for
	// container config.
	bridgeDevice := broker.agentConfig.Value(agent.LxcBridge)
	if bridgeDevice == "" {
		bridgeDevice = kvm.DefaultKvmBridge
	}
	network := container.BridgeNetworkConfig(bridgeDevice)

	series := args.Tools.OneSeries()
	args.MachineConfig.MachineContainerType = instance.KVM
	args.MachineConfig.Tools = args.Tools[0]

	config, err := broker.api.ContainerConfig()
	if err != nil {
		kvmLogger.Errorf("failed to get container config: %v", err)
		return nil, nil, nil, err
	}

	if err := environs.PopulateMachineConfig(
		args.MachineConfig,
		config.ProviderType,
		config.AuthorizedKeys,
		config.SSLHostnameVerification,
		config.Proxy,
		config.AptProxy,
		config.PreferIPv6,
		config.EnableOSRefreshUpdate,
		config.EnableOSUpgrade,
	); err != nil {
		kvmLogger.Errorf("failed to populate machine config: %v", err)
		return nil, nil, nil, err
	}

	inst, hardware, err := broker.manager.CreateContainer(args.MachineConfig, series, network)
	if err != nil {
		kvmLogger.Errorf("failed to start container: %v", err)
		return nil, nil, nil, err
	}
	kvmLogger.Infof("started kvm container for machineId: %s, %s, %s", machineId, inst.Id(), hardware.String())
	return inst, hardware, nil, nil
}

func CreateContainer(c *gc.C, manager container.Manager, machineId string) instance.Instance {
	stateInfo := jujutesting.FakeStateInfo(machineId)
	apiInfo := jujutesting.FakeAPIInfo(machineId)
	machineConfig := environs.NewMachineConfig(machineId, "fake-nonce", nil, stateInfo, apiInfo)
	machineConfig.Tools = &tools.Tools{
		Version: version.MustParseBinary("2.3.4-foo-bar"),
		URL:     "http://tools.testing.invalid/2.3.4-foo-bar.tgz",
	}

	series := "series"
	network := container.BridgeNetworkConfig("nic42")
	inst, hardware, err := manager.CreateContainer(machineConfig, series, network)
	c.Assert(err, gc.IsNil)
	c.Assert(hardware, gc.NotNil)
	c.Assert(hardware.String(), gc.Not(gc.Equals), "")
	return inst
}

// StartInstance is specified in the Broker interface.
func (broker *lxcBroker) StartInstance(args environs.StartInstanceParams) (instance.Instance, *instance.HardwareCharacteristics, []network.Info, error) {
	if args.MachineConfig.HasNetworks() {
		return nil, nil, nil, fmt.Errorf("starting lxc containers with networks is not supported yet.")
	}
	// TODO: refactor common code out of the container brokers.
	machineId := args.MachineConfig.MachineId
	lxcLogger.Infof("starting lxc container for machineId: %s", machineId)

	// Default to using the host network until we can configure.
	bridgeDevice := broker.agentConfig.Value(agent.LxcBridge)
	if bridgeDevice == "" {
		bridgeDevice = lxc.DefaultLxcBridge
	}
	network := container.BridgeNetworkConfig(bridgeDevice)

	series := args.Tools.OneSeries()
	args.MachineConfig.MachineContainerType = instance.LXC
	args.MachineConfig.Tools = args.Tools[0]

	config, err := broker.api.ContainerConfig()
	if err != nil {
		lxcLogger.Errorf("failed to get container config: %v", err)
		return nil, nil, nil, err
	}
	if err := environs.PopulateMachineConfig(
		args.MachineConfig,
		config.ProviderType,
		config.AuthorizedKeys,
		config.SSLHostnameVerification,
		config.Proxy,
		config.AptProxy,
	); err != nil {
		lxcLogger.Errorf("failed to populate machine config: %v", err)
		return nil, nil, nil, err
	}

	inst, hardware, err := broker.manager.CreateContainer(args.MachineConfig, series, network)
	if err != nil {
		lxcLogger.Errorf("failed to start container: %v", err)
		return nil, nil, nil, err
	}
	lxcLogger.Infof("started lxc container for machineId: %s, %s, %s", machineId, inst.Id(), hardware.String())
	return inst, hardware, nil, nil
}

func (s *UserDataSuite) TestNewCloudInitConfigWithNetworks(c *gc.C) {
	netConfig := container.BridgeNetworkConfig("foo", 0, s.fakeInterfaces)
	cloudConf, err := containerinit.NewCloudInitConfigWithNetworks("quantal", netConfig)
	c.Assert(err, jc.ErrorIsNil)
	// We need to indent expectNetConfig to make it valid YAML,
	// dropping the last new line and using unindented blank lines.
	lines := strings.Split(s.expectedNetConfig, "\n")
	indentedNetConfig := strings.Join(lines[:len(lines)-1], "\n  ")
	indentedNetConfig = strings.Replace(indentedNetConfig, "\n  \n", "\n\n", -1)
	expected := `
#cloud-config
bootcmd:
- install -D -m 644 /dev/null '`[1:] + s.networkInterfacesFile + `'
- |-
  printf '%s\n' '` + indentedNetConfig + `
  ' > '` + s.networkInterfacesFile + `'
`
	assertUserData(c, cloudConf, expected)
}

func (t *LxdSuite) TestNotAllContainersAreDeleted(c *gc.C) {
	c.Skip("Test skipped because it talks directly to LXD agent.")
	lxdClient, err := lxd.ConnectLocal("")
	c.Assert(err, jc.ErrorIsNil)

	/* create a container to make sure isn't deleted */
	instanceSpec := lxdclient.InstanceSpec{
		Name:  "juju-lxd-tests",
		Image: "ubuntu-xenial",
	}

	_, err = lxdClient.AddInstance(instanceSpec)
	c.Assert(err, jc.ErrorIsNil)
	defer lxdClient.RemoveInstances("", "juju-lxd-tests")

	instanceConfig, err := containertesting.MockMachineConfig("1/lxd/0")
	c.Assert(err, jc.ErrorIsNil)
	envConfig, err := config.New(config.NoDefaults, dummy.SampleConfig())
	c.Assert(err, jc.ErrorIsNil)
	instanceConfig.Config = envConfig
	storageConfig := &container.StorageConfig{}
	networkConfig := container.BridgeNetworkConfig("nic42", 4321, nil)

	manager := t.makeManager(c, "manager")
	callback := func(settableStatus status.Status, info string, data map[string]interface{}) error { return nil }
	_, _, err = manager.CreateContainer(
		instanceConfig,
		"xenial",
		networkConfig,
		storageConfig,
		callback,
	)
	c.Assert(err, jc.ErrorIsNil)

	instances, err := manager.ListContainers()
	c.Assert(err, jc.ErrorIsNil)

	for _, inst := range instances {
		err = manager.DestroyContainer(inst.Id())
		c.Assert(err, jc.ErrorIsNil)
	}
}