// links and mounts for service dependencies
func connectToAService(srv *definitions.Service, ops *definitions.Operation, typ, name, internalName string, link, mount bool) {
	log.WithFields(log.Fields{
		"=>":            srv.Name,
		"type":          typ,
		"name":          name,
		"internal name": internalName,
		"link":          link,
		"volumes from":  mount,
	}).Debug("Connecting to service")
	containerName := util.ContainersName(typ, name, ops.ContainerNumber)

	if link {
		newLink := containerName + ":" + internalName
		srv.Links = append(srv.Links, newLink)
	}

	if mount {
		// Automagically mount VolumesFrom for serviceDeps so they can
		// easily pass files back and forth. note that this is opinionated
		// and will mount as read-write. we can revisit this if read-only
		// mounting required for specific use cases
		newVol := containerName + ":rw"
		srv.VolumesFrom = append(srv.VolumesFrom, newVol)
	}
}

func configureDataContainer(srv *def.Service, ops *def.Operation, mainContOpts *docker.CreateContainerOptions) (docker.CreateContainerOptions, error) {
	// by default data containers will rely on the image used by
	//   the base service. sometimes, tho, especially for testing
	//   that base image will not be present. in such cases use
	//   the base eris data container.
	if srv.Image == "" {
		srv.Image = "eris/data"
	}

	opts := docker.CreateContainerOptions{
		Name: ops.DataContainerName,
		Config: &docker.Config{
			Image:           srv.Image,
			User:            srv.User,
			AttachStdin:     false,
			AttachStdout:    false,
			AttachStderr:    false,
			Tty:             false,
			OpenStdin:       false,
			NetworkDisabled: true, // data containers do not need to talk to the outside world.
			Entrypoint:      []string{},
			Cmd:             []string{"false"}, // just gracefully exit. data containers just need to "exist" not run.
		},
		HostConfig: &docker.HostConfig{},
	}

	if mainContOpts != nil {
		mainContOpts.HostConfig.VolumesFrom = append(mainContOpts.HostConfig.VolumesFrom, ops.DataContainerName)
	}

	return opts, nil
}

// links and mounts for service dependencies
func connectToAService(srv *definitions.Service, ops *definitions.Operation, typ, name, internalName string, link, mount bool) {
	logger.Debugf("Connecting service %s to %s %s (%s) with link (%v) and volumes-from (%v)\n", srv.Name, typ, name, internalName, link, mount)
	containerName := util.ContainersName(typ, name, ops.ContainerNumber)

	if link {
		newLink := containerName + ":" + internalName
		srv.Links = append(srv.Links, newLink)
	}

	if mount {
		// Automagically mount VolumesFrom for serviceDeps so they can
		// easily pass files back and forth. note that this is opinionated
		// and will mount as read-write. we can revisit this if read-only
		// mounting required for specific use cases
		newVol := containerName + ":rw"
		srv.VolumesFrom = append(srv.VolumesFrom, newVol)
	}
}

func configureDataContainer(srv *def.Service, ops *def.Operation, mainContOpts *docker.CreateContainerOptions) (docker.CreateContainerOptions, error) {
	// by default data containers will rely on the image used by
	//   the base service. sometimes, tho, especially for testing
	//   that base image will not be present. in such cases use
	//   the base eris data container.
	if srv.Image == "" {
		srv.Image = "quay.io/eris/data"
	}

	// Manipulate labels locally.
	labels := make(map[string]string)
	for k, v := range ops.Labels {
		labels[k] = v
	}

	// If connected to a service.
	if mainContOpts != nil {
		// Set the service container's VolumesFrom pointing to the data container.
		mainContOpts.HostConfig.VolumesFrom = append(mainContOpts.HostConfig.VolumesFrom, ops.DataContainerName)

		// Operations are inherited from the service container.
		labels = util.SetLabel(labels, def.LabelType, def.TypeData)

		// Set the data container service label pointing to the service.
		labels = util.SetLabel(labels, def.LabelService, mainContOpts.Name)
	}

	opts := docker.CreateContainerOptions{
		Name: ops.DataContainerName,
		Config: &docker.Config{
			Image:        srv.Image,
			User:         srv.User,
			AttachStdin:  false,
			AttachStdout: false,
			AttachStderr: false,
			Tty:          false,
			OpenStdin:    false,
			Labels:       labels,

			// Data containers do not need to talk to the outside world.
			NetworkDisabled: true,

			// Just gracefully exit. Data containers just need to "exist" not run.
			Entrypoint: []string{"true"},
			Cmd:        []string{},
		},
		HostConfig: &docker.HostConfig{},
	}

	return opts, nil
}