builder

type Backend interface {

	// GetImageOnBuild looks up a Docker image referenced by `name`.
	GetImageOnBuild(name string) (Image, error)
	// PullOnBuild tells Docker to pull image referenced by `name`.
	PullOnBuild(ctx context.Context, name string, authConfigs map[string]types.AuthConfig, output io.Writer) (Image, error)
	// ContainerAttachRaw attaches to container.
	ContainerAttachRaw(cID string, stdin io.ReadCloser, stdout, stderr io.Writer, stream bool, attached chan struct{}) error
	// ContainerCreate creates a new Docker container and returns potential warnings
	ContainerCreate(config types.ContainerCreateConfig) (container.ContainerCreateCreatedBody, error)
	// ContainerRm removes a container specified by `id`.
	ContainerRm(name string, config *types.ContainerRmConfig) error
	// Commit creates a new Docker image from an existing Docker container.
	Commit(string, *backend.ContainerCommitConfig) (string, error)
	// ContainerKill stops the container execution abruptly.
	ContainerKill(containerID string, sig uint64) error
	// ContainerStart starts a new container
	ContainerStart(containerID string, hostConfig *container.HostConfig, checkpoint string, checkpointDir string) error
	// ContainerWait stops processing until the given container is stopped.
	ContainerWait(containerID string, timeout time.Duration) (int, error)
	// ContainerCreateWorkdir creates the workdir
	ContainerCreateWorkdir(containerID string) error

	// ContainerCopy copies/extracts a source FileInfo to a destination path inside a container
	// specified by a container object.
	// TODO: extract in the builder instead of passing `decompress`
	// TODO: use containerd/fs.changestream instead as a source
	CopyOnBuild(containerID string, destPath string, srcRoot string, srcPath string, decompress bool) error

	// MountImage returns mounted path with rootfs of an image.
	MountImage(name string) (string, func() error, error)
}

type Image interface {
	ImageID() string
	RunConfig() *container.Config
}

type ImageCache interface {
	// GetCache returns a reference to a cached image whose parent equals `parent`
	// and runconfig equals `cfg`. A cache miss is expected to return an empty ID and a nil error.
	GetCache(parentID string, cfg *container.Config) (imageID string, err error)
}

type ImageCacheBuilder interface {
	// MakeImageCache creates a stateful image cache.
	MakeImageCache(cacheFrom []string) ImageCache
}

type Result struct {
	ImageID   string
	FromImage Image
}

type Source interface {
	// Root returns root path for accessing source
	Root() string
	// Close allows to signal that the filesystem tree won't be used anymore.
	// For Context implementations using a temporary directory, it is recommended to
	// delete the temporary directory in Close().
	Close() error
	// Hash returns a checksum for a file
	Hash(path string) (string, error)
}