func install(he vmextension.HandlerEnvironment, d driver.DistroDriver) error {
	// Install docker daemon
	log.Printf("++ install docker")
	if _, err := exec.LookPath("docker"); err == nil {
		log.Printf("docker already installed. not re-installing")
	} else {
		if err := d.InstallDocker(); err != nil {
			return err
		}
	}
	log.Printf("-- install docker")

	// Install docker-compose
	log.Printf("++ install docker-compose")
	if err := installCompose(d.DockerComposeDir()); err != nil {
		return fmt.Errorf("error installing docker-compose: %v", err)
	}
	log.Printf("-- install docker-compose")

	// Add user to 'docker' group to user docker as non-root
	u, err := util.GetAzureUser()
	if err != nil {
		return fmt.Errorf("failed to get provisioned user: %v", err)
	}
	log.Printf("++ add user to docker group")
	if out, err := executil.Exec("usermod", "-aG", "docker", u); err != nil {
		log.Printf("%s", string(out))
		return err
	}
	log.Printf("-- add user to docker group")

	return nil
}
func composeUp(d driver.DistroDriver, json map[string]interface{}) error {
	if len(json) == 0 {
		log.Println("docker-compose config not specified, noop")
		return nil
	}

	// Convert json to yaml
	yaml, err := yaml.Marshal(json)
	if err != nil {
		return fmt.Errorf("error converting to compose.yml: %v", err)
	}

	tmpDir, err := ioutil.TempDir(os.TempDir(), "compose")
	if err != nil {
		return fmt.Errorf("failed creating temp dir: %v", err)
	}
	log.Printf("Using compose yaml:---------\n%s\n----------", string(yaml))
	ymlPath := filepath.Join(tmpDir, composeYml)
	if err := ioutil.WriteFile(ymlPath, yaml, 0666); err != nil {
		return fmt.Errorf("error writing yaml: %v", err)
	}

	compose := filepath.Join(d.DockerComposeDir(), composeBin)
	return executil.ExecPipe(compose, "-f", ymlPath, "up", "-d")
}
func composeUp(d driver.DistroDriver, json map[string]interface{}) error {
	if len(json) == 0 {
		log.Println("docker-compose config not specified, noop")
		return nil
	}

	// Convert json to yaml
	yaml, err := yaml.Marshal(json)
	if err != nil {
		return fmt.Errorf("error converting to compose.yml: %v", err)
	}

	if err := os.MkdirAll(composeDir, 0777); err != nil {
		return fmt.Errorf("failed creating %s: %v", composeDir, err)
	}
	log.Printf("Using compose yaml:>>>>>\n%s\n<<<<<", string(yaml))
	ymlPath := filepath.Join(composeDir, composeYml)
	if err := ioutil.WriteFile(ymlPath, yaml, 0666); err != nil {
		return fmt.Errorf("error writing %s: %v", ymlPath, err)
	}

	compose := filepath.Join(d.DockerComposeDir(), composeBin)
	return executil.ExecPipeToFds(executil.Fds{Out: ioutil.Discard}, compose, "-p", composeProject, "-f", ymlPath, "up", "-d")
}