docker.go

package sti

import (
	"log"

	"github.com/fsouza/go-dockerclient"
)

// Determines whether the supplied image is in the local registry.
func (h requestHandler) isImageInLocalRegistry(imageName string) (bool, error) {
	image, err := h.dockerClient.InspectImage(imageName)

	if image != nil {
		return true, nil
	} else if err == docker.ErrNoSuchImage {
		return false, nil
	}

	return false, err
}

// Pull an image into the local registry
func (h requestHandler) checkAndPull(imageName string) (*docker.Image, error) {
	image, err := h.dockerClient.InspectImage(imageName)
	if err != nil && err != docker.ErrNoSuchImage {
		//TODO should this be a different error?
		return nil, ErrPullImageFailed
	}

	if image == nil {
		log.Printf("Pulling image %s\n", imageName)

		err = h.dockerClient.PullImage(docker.PullImageOptions{Repository: imageName}, docker.AuthConfiguration{})
		if err != nil {
			return nil, ErrPullImageFailed
		}

		image, err = h.dockerClient.InspectImage(imageName)
		if err != nil {
			return nil, err
		}
	} else if h.request.Verbose {
		log.Printf("Image %s available locally\n", imageName)
	}

	return image, nil
}

// Creates a container from a given image name and returns the ID of the created container.
func (h requestHandler) containerFromImage(imageName string) (*docker.Container, error) {
	config := docker.Config{Image: imageName, AttachStdout: false, AttachStderr: false, Cmd: []string{"/bin/true"}}
	container, err := h.dockerClient.CreateContainer(docker.CreateContainerOptions{Name: "", Config: &config})
	if err != nil {
		return nil, err
	}

	err = h.dockerClient.StartContainer(container.ID, &docker.HostConfig{})
	if err != nil {
		return nil, err
	}

	exitCode, err := h.dockerClient.WaitContainer(container.ID)
	if err != nil {
		return nil, err
	}

	if exitCode != 0 {
		log.Printf("Container exit code: %d\n", exitCode)
		return nil, ErrCreateContainerFailed
	}

	return container, nil
}

// Remove a container and its associated volumes.
func (h requestHandler) removeContainer(id string) {
	h.dockerClient.RemoveContainer(docker.RemoveContainerOptions{id, true, true})
}

// Commit the container with the given ID with the given tag.
func (h requestHandler) commitContainer(id, tag string) error {
	// TODO: commit message / author?
	_, err := h.dockerClient.CommitContainer(docker.CommitContainerOptions{Container: id, Repository: tag})
	return err
}