os/init/sysinit.go

package init

import (
	"os"
	"path"
	"syscall"

	log "github.com/Sirupsen/logrus"
	dockerClient "github.com/fsouza/go-dockerclient"
	"github.com/rancherio/os/config"
	"github.com/rancherio/os/docker"
	"github.com/rancherio/os/util"
)

func importImage(client *dockerClient.Client, name, fileName string) error {
	file, err := os.Open(fileName)
	if err != nil {
		return err
	}

	defer file.Close()

	log.Debugf("Importing image for %s", fileName)
	repo, tag := dockerClient.ParseRepositoryTag(name)
	return client.ImportImage(dockerClient.ImportImageOptions{
		Source:      "-",
		Repository:  repo,
		Tag:         tag,
		InputStream: file,
	})
}

func hasImage(name string) bool {
	stamp := path.Join(STATE, name)
	if _, err := os.Stat(stamp); os.IsNotExist(err) {
		return false
	}
	return true
}

func findImages(cfg *config.Config) ([]string, error) {
	log.Debugf("Looking for images at %s", config.IMAGES_PATH)

	result := []string{}

	dir, err := os.Open(config.IMAGES_PATH)
	if os.IsNotExist(err) {
		log.Debugf("Not loading images, %s does not exist")
		return result, nil
	}
	if err != nil {
		return nil, err
	}

	defer dir.Close()

	files, err := dir.Readdirnames(0)
	if err != nil {
		return nil, err
	}

	for _, fileName := range files {
		if ok, _ := path.Match(config.IMAGES_PATTERN, fileName); ok {
			log.Debugf("Found %s", fileName)
			result = append(result, fileName)
		}
	}

	return result, nil
}

func loadImages(cfg *config.Config) error {
	images, err := findImages(cfg)
	if err != nil || len(images) == 0 {
		return err
	}

	client, err := docker.NewSystemClient()
	if err != nil {
		return err
	}

	for _, image := range images {
		if hasImage(image) {
			continue
		}

		inputFileName := path.Join(config.IMAGES_PATH, image)
		input, err := os.Open(inputFileName)
		if err != nil {
			return err
		}

		defer input.Close()

		log.Infof("Loading images from %s", inputFileName)
		err = client.LoadImage(dockerClient.LoadImageOptions{
			InputStream: input,
		})
		log.Infof("Done loading images from %s", inputFileName)

		if err != nil {
			return err
		}
	}

	return nil
}

func runContainersFrom(startFrom string, cfg *config.Config, containerConfigs []config.ContainerConfig) error {
	foundStart := false

	for i, containerConfig := range containerConfigs {
		container := docker.NewContainer(config.DOCKER_SYSTEM_HOST, &containerConfig)

		if util.Contains(cfg.Disable, containerConfig.Id) {
			log.Infof("%s is disabled : %v", containerConfig.Id, cfg.Disable)
			continue
		}

		if foundStart || startFrom == "" {

			if containerConfig.CreateOnly {
				log.Infof("Creating [%d/%d] %s", i+1, len(containerConfigs), containerConfig.Id)
				container.Create()
			} else {
				log.Infof("Running [%d/%d] %s", i+1, len(containerConfigs), containerConfig.Id)
				container.StartAndWait()
			}

			if container.Err != nil {
				log.Errorf("Failed to run %v: %v", containerConfig.Id, container.Err)
			}

			if containerConfig.ReloadConfig {
				log.Info("Reloading configuration")
				err := cfg.Reload()
				if err != nil {
					return err
				}

				return runContainersFrom(containerConfig.Id, cfg, cfg.SystemContainers)
			}
		} else if startFrom == containerConfig.Id {
			foundStart = true
		}
	}

	return nil
}

func runContainers(cfg *config.Config) error {
	return runContainersFrom("", cfg, cfg.SystemContainers)
}

func tailConsole(cfg *config.Config) error {
	if !cfg.Console.Tail {
		return nil
	}

	client, err := docker.NewSystemClient()
	if err != nil {
		return err
	}

	for _, container := range cfg.SystemContainers {
		if container.Id != config.CONSOLE_CONTAINER {
			continue
		}

		c := docker.NewContainer(config.DOCKER_SYSTEM_HOST, &container).Lookup()
		if c.Err != nil {
			continue
		}

		log.Infof("Tailing console : %s", c.Name)
		return client.Logs(dockerClient.LogsOptions{
			Container:    c.Name,
			Stdout:       true,
			Stderr:       true,
			Follow:       true,
			OutputStream: os.Stdout,
			ErrorStream:  os.Stderr,
		})
	}

	log.Error("Console not found")
	return nil
}

func SysInit() error {
	cfg, err := config.LoadConfig()
	if err != nil {
		return err
	}

	initFuncs := []config.InitFunc{
		loadImages,
		runContainers,
		func(cfg *config.Config) error {
			syscall.Sync()
			return nil
		},
		tailConsole,
	}

	return config.RunInitFuncs(cfg, initFuncs)
}