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moby--moby/builder/dockerfile/imagecontext.go
Daniel Nephin 4f0d95fa6e Add canonical import comment
Signed-off-by: Daniel Nephin <dnephin@docker.com>
2018-02-05 16:51:57 -05:00

142 lines
3.6 KiB
Go

package dockerfile // import "github.com/docker/docker/builder/dockerfile"
import (
"runtime"
"github.com/docker/docker/api/types/backend"
"github.com/docker/docker/builder"
"github.com/docker/docker/builder/remotecontext"
dockerimage "github.com/docker/docker/image"
"github.com/docker/docker/pkg/system"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"golang.org/x/net/context"
)
type getAndMountFunc func(string, bool) (builder.Image, builder.ReleaseableLayer, error)
// imageSources mounts images and provides a cache for mounted images. It tracks
// all images so they can be unmounted at the end of the build.
type imageSources struct {
byImageID map[string]*imageMount
mounts []*imageMount
getImage getAndMountFunc
}
func newImageSources(ctx context.Context, options builderOptions) *imageSources {
getAndMount := func(idOrRef string, localOnly bool) (builder.Image, builder.ReleaseableLayer, error) {
pullOption := backend.PullOptionNoPull
if !localOnly {
if options.Options.PullParent {
pullOption = backend.PullOptionForcePull
} else {
pullOption = backend.PullOptionPreferLocal
}
}
optionsPlatform := system.ParsePlatform(options.Options.Platform)
return options.Backend.GetImageAndReleasableLayer(ctx, idOrRef, backend.GetImageAndLayerOptions{
PullOption: pullOption,
AuthConfig: options.Options.AuthConfigs,
Output: options.ProgressWriter.Output,
OS: optionsPlatform.OS,
})
}
return &imageSources{
byImageID: make(map[string]*imageMount),
getImage: getAndMount,
}
}
func (m *imageSources) Get(idOrRef string, localOnly bool) (*imageMount, error) {
if im, ok := m.byImageID[idOrRef]; ok {
return im, nil
}
image, layer, err := m.getImage(idOrRef, localOnly)
if err != nil {
return nil, err
}
im := newImageMount(image, layer)
m.Add(im)
return im, nil
}
func (m *imageSources) Unmount() (retErr error) {
for _, im := range m.mounts {
if err := im.unmount(); err != nil {
logrus.Error(err)
retErr = err
}
}
return
}
func (m *imageSources) Add(im *imageMount) {
switch im.image {
case nil:
// set the OS for scratch images
os := runtime.GOOS
// Windows does not support scratch except for LCOW
if runtime.GOOS == "windows" {
os = "linux"
}
im.image = &dockerimage.Image{V1Image: dockerimage.V1Image{OS: os}}
default:
m.byImageID[im.image.ImageID()] = im
}
m.mounts = append(m.mounts, im)
}
// imageMount is a reference to an image that can be used as a builder.Source
type imageMount struct {
image builder.Image
source builder.Source
layer builder.ReleaseableLayer
}
func newImageMount(image builder.Image, layer builder.ReleaseableLayer) *imageMount {
im := &imageMount{image: image, layer: layer}
return im
}
func (im *imageMount) Source() (builder.Source, error) {
if im.source == nil {
if im.layer == nil {
return nil, errors.Errorf("empty context")
}
mountPath, err := im.layer.Mount()
if err != nil {
return nil, errors.Wrapf(err, "failed to mount %s", im.image.ImageID())
}
source, err := remotecontext.NewLazySource(mountPath)
if err != nil {
return nil, errors.Wrapf(err, "failed to create lazycontext for %s", mountPath)
}
im.source = source
}
return im.source, nil
}
func (im *imageMount) unmount() error {
if im.layer == nil {
return nil
}
if err := im.layer.Release(); err != nil {
return errors.Wrapf(err, "failed to unmount previous build image %s", im.image.ImageID())
}
im.layer = nil
return nil
}
func (im *imageMount) Image() builder.Image {
return im.image
}
func (im *imageMount) Layer() builder.ReleaseableLayer {
return im.layer
}
func (im *imageMount) ImageID() string {
return im.image.ImageID()
}