Beispiel #1
0
// updateSupportedContainers records in state that a machine can run the specified containers.
// It starts a watcher and when a container of a given type is first added to the machine,
// the watcher is killed, the machine is set up to be able to start containers of the given type,
// and a suitable provisioner is started.
func (a *MachineAgent) updateSupportedContainers(
	runner worker.Runner,
	st api.Connection,
	containers []instance.ContainerType,
	agentConfig agent.Config,
) error {
	pr := st.Provisioner()
	tag := agentConfig.Tag().(names.MachineTag)
	machine, err := pr.Machine(tag)
	if errors.IsNotFound(err) || err == nil && machine.Life() == params.Dead {
		return worker.ErrTerminateAgent
	}
	if err != nil {
		return errors.Annotatef(err, "cannot load machine %s from state", tag)
	}
	if len(containers) == 0 {
		if err := machine.SupportsNoContainers(); err != nil {
			return errors.Annotatef(err, "clearing supported containers for %s", tag)
		}
		return nil
	}
	if err := machine.SetSupportedContainers(containers...); err != nil {
		return errors.Annotatef(err, "setting supported containers for %s", tag)
	}
	initLock, err := cmdutil.HookExecutionLock(agentConfig.DataDir())
	if err != nil {
		return err
	}
	// Start the watcher to fire when a container is first requested on the machine.
	modelUUID, err := st.ModelTag()
	if err != nil {
		return err
	}
	watcherName := fmt.Sprintf("%s-container-watcher", machine.Id())
	// There may not be a CA certificate private key available, and without
	// it we can't ensure that other Juju nodes can connect securely, so only
	// use an image URL getter if there's a private key.
	var imageURLGetter container.ImageURLGetter
	if agentConfig.Value(agent.AllowsSecureConnection) == "true" {
		cfg, err := pr.ModelConfig()
		if err != nil {
			return errors.Annotate(err, "unable to get environ config")
		}
		imageURLGetter = container.NewImageURLGetter(
			// Explicitly call the non-named constructor so if anyone
			// adds additional fields, this fails.
			container.ImageURLGetterConfig{
				ServerRoot:        st.Addr(),
				ModelUUID:         modelUUID.Id(),
				CACert:            []byte(agentConfig.CACert()),
				CloudimgBaseUrl:   cfg.CloudImageBaseURL(),
				Stream:            cfg.ImageStream(),
				ImageDownloadFunc: container.ImageDownloadURL,
			})
	}
	params := provisioner.ContainerSetupParams{
		Runner:              runner,
		WorkerName:          watcherName,
		SupportedContainers: containers,
		ImageURLGetter:      imageURLGetter,
		Machine:             machine,
		Provisioner:         pr,
		Config:              agentConfig,
		InitLock:            initLock,
	}
	handler := provisioner.NewContainerSetupHandler(params)
	a.startWorkerAfterUpgrade(runner, watcherName, func() (worker.Worker, error) {
		w, err := watcher.NewStringsWorker(watcher.StringsConfig{
			Handler: handler,
		})
		if err != nil {
			return nil, errors.Annotatef(err, "cannot start %s worker", watcherName)
		}
		return w, nil
	})
	return nil
}