code: func NewDeployHandlerFromConfig(host, prefix string, cfg *Config) (*DeployHandler, error) {
  	if cfg == nil {
  		panic("NewDeployHandlerFromConfig: nil config")
  	}
  	if cfg.ClientID == "" {
  		return nil, errors.New("oauth2 clientID required in config")
  	}
  	if cfg.ClientSecret == "" {
  		return nil, errors.New("oauth2 clientSecret required in config")
  	}
  	os.Setenv("CAMLI_GCE_CLIENTID", cfg.ClientID)
  	os.Setenv("CAMLI_GCE_CLIENTSECRET", cfg.ClientSecret)
  	os.Setenv("CAMLI_GCE_PROJECT", cfg.Project)
  	os.Setenv("CAMLI_GCE_SERVICE_ACCOUNT", cfg.ServiceAccount)
  	os.Setenv("CAMLI_GCE_DATA", cfg.DataDir)
  	return NewDeployHandler(host, prefix)
  }
docs: // NewDeployHandlerFromConfig initializes a DeployHandler from cfg.
  // Host and prefix have the same meaning as for NewDeployHandler. cfg should not be nil.