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
}