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Refactor imageContexts into two different structs.

buildStages now tracks the imageID and runConfig for a build stage

imageMounter tracks image mounts so they can released when the build ends.

Signed-off-by: Daniel Nephin <dnephin@docker.com>
This commit is contained in:
Daniel Nephin 2017-05-05 18:52:11 -04:00
parent ab3a037a5b
commit 6c28e8edd5
9 changed files with 229 additions and 156 deletions

View file

@ -23,7 +23,7 @@ type BuildConfig struct {
Options *types.ImageBuildOptions Options *types.ImageBuildOptions
} }
// GetImageAndLayerOptions are the options supported by GetImageAndLayer // GetImageAndLayerOptions are the options supported by GetImageAndReleasableLayer
type GetImageAndLayerOptions struct { type GetImageAndLayerOptions struct {
ForcePull bool ForcePull bool
AuthConfig map[string]types.AuthConfig AuthConfig map[string]types.AuthConfig

View file

@ -34,7 +34,7 @@ type Source interface {
// Backend abstracts calls to a Docker Daemon. // Backend abstracts calls to a Docker Daemon.
type Backend interface { type Backend interface {
GetImageAndLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (Image, ReleaseableLayer, error) ImageBackend
// ContainerAttachRaw attaches to container. // ContainerAttachRaw attaches to container.
ContainerAttachRaw(cID string, stdin io.ReadCloser, stdout, stderr io.Writer, stream bool, attached chan struct{}) error ContainerAttachRaw(cID string, stdin io.ReadCloser, stdout, stderr io.Writer, stream bool, attached chan struct{}) error
@ -60,6 +60,11 @@ type Backend interface {
CopyOnBuild(containerID string, destPath string, srcRoot string, srcPath string, decompress bool) error CopyOnBuild(containerID string, destPath string, srcRoot string, srcPath string, decompress bool) error
} }
// ImageBackend are the interface methods required from an image component
type ImageBackend interface {
GetImageAndReleasableLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (Image, ReleaseableLayer, error)
}
// Result is the output produced by a Builder // Result is the output produced by a Builder
type Result struct { type Result struct {
ImageID string ImageID string
@ -89,5 +94,5 @@ type Image interface {
// ReleaseableLayer is an image layer that can be mounted and released // ReleaseableLayer is an image layer that can be mounted and released
type ReleaseableLayer interface { type ReleaseableLayer interface {
Release() error Release() error
Mount(string) (string, error) Mount() (string, error)
} }

View file

@ -102,11 +102,12 @@ type Builder struct {
clientCtx context.Context clientCtx context.Context
tmpContainers map[string]struct{} tmpContainers map[string]struct{}
imageContexts *imageContexts // helper for storing contexts from builds buildStages *buildStages
disableCommit bool disableCommit bool
cacheBusted bool cacheBusted bool
buildArgs *buildArgs buildArgs *buildArgs
imageCache builder.ImageCache imageCache builder.ImageCache
imageSources *imageSources
} }
// newBuilder creates a new Dockerfile builder from an optional dockerfile and a Options. // newBuilder creates a new Dockerfile builder from an optional dockerfile and a Options.
@ -125,7 +126,8 @@ func newBuilder(clientCtx context.Context, options builderOptions) *Builder {
docker: options.Backend, docker: options.Backend,
tmpContainers: map[string]struct{}{}, tmpContainers: map[string]struct{}{},
buildArgs: newBuildArgs(config.BuildArgs), buildArgs: newBuildArgs(config.BuildArgs),
imageContexts: &imageContexts{}, buildStages: newBuildStages(),
imageSources: newImageSources(clientCtx, options),
} }
return b return b
} }
@ -140,7 +142,7 @@ func (b *Builder) resetImageCache() {
// Build runs the Dockerfile builder by parsing the Dockerfile and executing // Build runs the Dockerfile builder by parsing the Dockerfile and executing
// the instructions from the file. // the instructions from the file.
func (b *Builder) build(source builder.Source, dockerfile *parser.Result) (*builder.Result, error) { func (b *Builder) build(source builder.Source, dockerfile *parser.Result) (*builder.Result, error) {
defer b.imageContexts.unmount() defer b.imageSources.Unmount()
// TODO: Remove source field from Builder // TODO: Remove source field from Builder
b.source = source b.source = source

View file

@ -20,9 +20,9 @@ import (
"github.com/Sirupsen/logrus" "github.com/Sirupsen/logrus"
"github.com/docker/docker/api" "github.com/docker/docker/api"
"github.com/docker/docker/api/types" "github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/backend"
"github.com/docker/docker/api/types/container" "github.com/docker/docker/api/types/container"
"github.com/docker/docker/api/types/strslice" "github.com/docker/docker/api/types/strslice"
"github.com/docker/docker/builder"
"github.com/docker/docker/builder/dockerfile/parser" "github.com/docker/docker/builder/dockerfile/parser"
"github.com/docker/docker/pkg/signal" "github.com/docker/docker/pkg/signal"
"github.com/docker/go-connections/nat" "github.com/docker/go-connections/nat"
@ -174,14 +174,19 @@ func dispatchCopy(req dispatchRequest) error {
func (b *Builder) getImageMount(fromFlag *Flag) (*imageMount, error) { func (b *Builder) getImageMount(fromFlag *Flag) (*imageMount, error) {
if !fromFlag.IsUsed() { if !fromFlag.IsUsed() {
// TODO: this could return the mount in the default case as well // TODO: this could return the source in the default case as well?
return nil, nil return nil, nil
} }
im, err := b.imageContexts.getMount(fromFlag.Value)
if err != nil || im != nil { imageRefOrID := fromFlag.Value
return im, err stage, err := b.buildStages.get(fromFlag.Value)
if err != nil {
return nil, err
} }
return b.getImage(fromFlag.Value) if stage != nil {
imageRefOrID = stage.ImageID()
}
return b.imageSources.Get(imageRefOrID)
} }
// FROM imagename[:tag | @digest] [AS build-stage-name] // FROM imagename[:tag | @digest] [AS build-stage-name]
@ -201,7 +206,7 @@ func from(req dispatchRequest) error {
if err != nil { if err != nil {
return err return err
} }
if err := req.builder.imageContexts.add(stageName, image); err != nil { if err := req.builder.buildStages.add(stageName, image); err != nil {
return err return err
} }
req.state.beginStage(stageName, image) req.state.beginStage(stageName, image)
@ -229,7 +234,12 @@ func parseBuildStageName(args []string) (string, error) {
return stageName, nil return stageName, nil
} }
func (b *Builder) getFromImage(shlex *ShellLex, name string) (*imageMount, error) { // scratchImage is used as a token for the empty base image. It uses buildStage
// as a convenient implementation of builder.Image, but is not actually a
// buildStage.
var scratchImage builder.Image = &buildStage{}
func (b *Builder) getFromImage(shlex *ShellLex, name string) (builder.Image, error) {
substitutionArgs := []string{} substitutionArgs := []string{}
for key, value := range b.buildArgs.GetAllMeta() { for key, value := range b.buildArgs.GetAllMeta() {
substitutionArgs = append(substitutionArgs, key+"="+value) substitutionArgs = append(substitutionArgs, key+"="+value)
@ -240,7 +250,7 @@ func (b *Builder) getFromImage(shlex *ShellLex, name string) (*imageMount, error
return nil, err return nil, err
} }
if im, ok := b.imageContexts.byName[name]; ok { if im, ok := b.buildStages.getByName(name); ok {
return im, nil return im, nil
} }
@ -249,21 +259,13 @@ func (b *Builder) getFromImage(shlex *ShellLex, name string) (*imageMount, error
if runtime.GOOS == "windows" { if runtime.GOOS == "windows" {
return nil, errors.New("Windows does not support FROM scratch") return nil, errors.New("Windows does not support FROM scratch")
} }
return newImageMount(nil, nil), nil return scratchImage, nil
} }
return b.getImage(name) imageMount, err := b.imageSources.Get(name)
}
func (b *Builder) getImage(name string) (*imageMount, error) {
image, layer, err := b.docker.GetImageAndLayer(b.clientCtx, name, backend.GetImageAndLayerOptions{
ForcePull: b.options.PullParent,
AuthConfig: b.options.AuthConfigs,
Output: b.Output,
})
if err != nil { if err != nil {
return nil, err return nil, err
} }
return newImageMount(image, layer), nil return imageMount.Image(), nil
} }
func processOnBuild(req dispatchRequest) error { func processOnBuild(req dispatchRequest) error {

View file

@ -49,15 +49,20 @@ func defaultDispatchReq(builder *Builder, args ...string) dispatchRequest {
func newBuilderWithMockBackend() *Builder { func newBuilderWithMockBackend() *Builder {
mockBackend := &MockBackend{} mockBackend := &MockBackend{}
ctx := context.Background()
b := &Builder{ b := &Builder{
options: &types.ImageBuildOptions{}, options: &types.ImageBuildOptions{},
docker: mockBackend, docker: mockBackend,
buildArgs: newBuildArgs(make(map[string]*string)), buildArgs: newBuildArgs(make(map[string]*string)),
tmpContainers: make(map[string]struct{}), tmpContainers: make(map[string]struct{}),
Stdout: new(bytes.Buffer), Stdout: new(bytes.Buffer),
clientCtx: context.Background(), clientCtx: ctx,
disableCommit: true, disableCommit: true,
imageContexts: &imageContexts{}, imageSources: newImageSources(ctx, builderOptions{
Options: &types.ImageBuildOptions{},
Backend: mockBackend,
}),
buildStages: newBuildStages(),
} }
return b return b
} }

View file

@ -5,10 +5,12 @@ import (
"strings" "strings"
"github.com/Sirupsen/logrus" "github.com/Sirupsen/logrus"
"github.com/docker/docker/api/types/backend"
"github.com/docker/docker/api/types/container" "github.com/docker/docker/api/types/container"
"github.com/docker/docker/builder" "github.com/docker/docker/builder"
"github.com/docker/docker/builder/remotecontext" "github.com/docker/docker/builder/remotecontext"
"github.com/pkg/errors" "github.com/pkg/errors"
"golang.org/x/net/context"
) )
type pathCache interface { type pathCache interface {
@ -16,35 +18,63 @@ type pathCache interface {
Store(key, value interface{}) Store(key, value interface{})
} }
// imageContexts is a helper for stacking up built image rootfs and reusing type buildStage struct {
// them as contexts id string
type imageContexts struct { config *container.Config
list []*imageMount
byName map[string]*imageMount
cache pathCache
} }
func (ic *imageContexts) add(name string, im *imageMount) error { func newBuildStageFromImage(image builder.Image) *buildStage {
if len(name) > 0 { return &buildStage{id: image.ImageID(), config: image.RunConfig()}
if ic.byName == nil { }
ic.byName = make(map[string]*imageMount)
func (b *buildStage) ImageID() string {
return b.id
}
func (b *buildStage) RunConfig() *container.Config {
return b.config
}
func (b *buildStage) update(imageID string, runConfig *container.Config) {
b.id = imageID
b.config = runConfig
}
var _ builder.Image = &buildStage{}
// buildStages tracks each stage of a build so they can be retrieved by index
// or by name.
type buildStages struct {
sequence []*buildStage
byName map[string]*buildStage
}
func newBuildStages() *buildStages {
return &buildStages{byName: make(map[string]*buildStage)}
}
func (s *buildStages) getByName(name string) (builder.Image, bool) {
stage, ok := s.byName[strings.ToLower(name)]
return stage, ok
}
func (s *buildStages) get(indexOrName string) (builder.Image, error) {
index, err := strconv.Atoi(indexOrName)
if err == nil {
if err := s.validateIndex(index); err != nil {
return nil, err
} }
if _, ok := ic.byName[name]; ok { return s.sequence[index], nil
return errors.Errorf("duplicate name %s", name)
}
ic.byName[name] = im
} }
ic.list = append(ic.list, im) if im, ok := s.byName[strings.ToLower(indexOrName)]; ok {
return nil return im, nil
}
return nil, nil
} }
func (ic *imageContexts) update(imageID string, runConfig *container.Config) { func (s *buildStages) validateIndex(i int) error {
ic.list[len(ic.list)-1].update(imageID, runConfig) if i < 0 || i >= len(s.sequence)-1 {
} if i == len(s.sequence)-1 {
func (ic *imageContexts) validate(i int) error {
if i < 0 || i >= len(ic.list)-1 {
if i == len(ic.list)-1 {
return errors.New("refers to current build stage") return errors.New("refers to current build stage")
} }
return errors.New("index out of bounds") return errors.New("index out of bounds")
@ -52,30 +82,64 @@ func (ic *imageContexts) validate(i int) error {
return nil return nil
} }
func (ic *imageContexts) getMount(indexOrName string) (*imageMount, error) { func (s *buildStages) add(name string, image builder.Image) error {
index, err := strconv.Atoi(indexOrName) stage := newBuildStageFromImage(image)
if err == nil { name = strings.ToLower(name)
if err := ic.validate(index); err != nil { if len(name) > 0 {
return nil, err if _, ok := s.byName[name]; ok {
return errors.Errorf("duplicate name %s", name)
} }
return ic.list[index], nil s.byName[name] = stage
} }
if im, ok := ic.byName[strings.ToLower(indexOrName)]; ok { s.sequence = append(s.sequence, stage)
return im, nil return nil
}
return nil, nil
} }
func (ic *imageContexts) unmount() (retErr error) { func (s *buildStages) update(imageID string, runConfig *container.Config) {
for _, iml := range append([][]*imageMount{}, ic.list, ic.implicitMounts) { s.sequence[len(s.sequence)-1].update(imageID, runConfig)
for _, im := range iml { }
if err := im.unmount(); err != nil {
logrus.Error(err) type getAndMountFunc func(string) (builder.Image, builder.ReleaseableLayer, error)
retErr = err
} // 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
getImage getAndMountFunc
cache pathCache // TODO: remove
}
func newImageSources(ctx context.Context, options builderOptions) *imageSources {
getAndMount := func(idOrRef string) (builder.Image, builder.ReleaseableLayer, error) {
return options.Backend.GetImageAndReleasableLayer(ctx, idOrRef, backend.GetImageAndLayerOptions{
ForcePull: options.Options.PullParent,
AuthConfig: options.Options.AuthConfigs,
Output: options.ProgressWriter.Output,
})
} }
for _, im := range ic.byName {
return &imageSources{
byImageID: make(map[string]*imageMount),
getImage: getAndMount,
}
}
func (m *imageSources) Get(idOrRef string) (*imageMount, error) {
if im, ok := m.byImageID[idOrRef]; ok {
return im, nil
}
image, layer, err := m.getImage(idOrRef)
if err != nil {
return nil, err
}
im := newImageMount(image, layer)
m.byImageID[image.ImageID()] = im
return im, nil
}
func (m *imageSources) Unmount() (retErr error) {
for _, im := range m.byImageID {
if err := im.unmount(); err != nil { if err := im.unmount(); err != nil {
logrus.Error(err) logrus.Error(err)
retErr = err retErr = err
@ -84,47 +148,43 @@ func (ic *imageContexts) unmount() (retErr error) {
return return
} }
// TODO: remove getCache/setCache from imageContexts // TODO: remove getCache/setCache from imageSources
func (ic *imageContexts) getCache(id, path string) (interface{}, bool) { func (m *imageSources) getCache(id, path string) (interface{}, bool) {
if ic.cache != nil { if m.cache != nil {
if id == "" { if id == "" {
return nil, false return nil, false
} }
return ic.cache.Load(id + path) return m.cache.Load(id + path)
} }
return nil, false return nil, false
} }
func (ic *imageContexts) setCache(id, path string, v interface{}) { func (m *imageSources) setCache(id, path string, v interface{}) {
if ic.cache != nil { if m.cache != nil {
ic.cache.Store(id+path, v) m.cache.Store(id+path, v)
} }
} }
// imageMount is a reference to an image that can be used as a builder.Source // imageMount is a reference to an image that can be used as a builder.Source
type imageMount struct { type imageMount struct {
id string image builder.Image
source builder.Source source builder.Source
runConfig *container.Config layer builder.ReleaseableLayer
layer builder.ReleaseableLayer
} }
func newImageMount(image builder.Image, layer builder.ReleaseableLayer) *imageMount { func newImageMount(image builder.Image, layer builder.ReleaseableLayer) *imageMount {
im := &imageMount{layer: layer} im := &imageMount{image: image, layer: layer}
if image != nil {
im.update(image.ImageID(), image.RunConfig())
}
return im return im
} }
func (im *imageMount) context() (builder.Source, error) { func (im *imageMount) Source() (builder.Source, error) {
if im.source == nil { if im.source == nil {
if im.id == "" || im.layer == nil { if im.layer == nil {
return nil, errors.Errorf("empty context") return nil, errors.Errorf("empty context")
} }
mountPath, err := im.layer.Mount(im.id) mountPath, err := im.layer.Mount()
if err != nil { if err != nil {
return nil, errors.Wrapf(err, "failed to mount %s", im.id) return nil, errors.Wrapf(err, "failed to mount %s", im.image.ImageID())
} }
source, err := remotecontext.NewLazyContext(mountPath) source, err := remotecontext.NewLazyContext(mountPath)
if err != nil { if err != nil {
@ -140,20 +200,11 @@ func (im *imageMount) unmount() error {
return nil return nil
} }
if err := im.layer.Release(); err != nil { if err := im.layer.Release(); err != nil {
return errors.Wrapf(err, "failed to unmount previous build image %s", im.id) return errors.Wrapf(err, "failed to unmount previous build image %s", im.image.ImageID())
} }
return nil return nil
} }
func (im *imageMount) update(imageID string, runConfig *container.Config) { func (im *imageMount) Image() builder.Image {
im.id = imageID return im.image
im.runConfig = runConfig
}
func (im *imageMount) ImageID() string {
return im.id
}
func (im *imageMount) RunConfig() *container.Config {
return im.runConfig
} }

View file

@ -78,7 +78,7 @@ func (b *Builder) commitContainer(dispatchState *dispatchState, id string, conta
} }
dispatchState.imageID = imageID dispatchState.imageID = imageID
b.imageContexts.update(imageID, dispatchState.runConfig) b.buildStages.update(imageID, dispatchState.runConfig)
return nil return nil
} }
@ -369,7 +369,7 @@ func (b *Builder) calcCopyInfo(cmdName, origPath string, allowLocalDecompression
source := b.source source := b.source
var err error var err error
if imageSource != nil { if imageSource != nil {
source, err = imageSource.context() source, err = imageSource.Source()
if err != nil { if err != nil {
return nil, errors.Wrapf(err, "failed to copy") return nil, errors.Wrapf(err, "failed to copy")
} }
@ -427,7 +427,7 @@ func (b *Builder) calcCopyInfo(cmdName, origPath string, allowLocalDecompression
if imageSource != nil { if imageSource != nil {
// fast-cache based on imageID // fast-cache based on imageID
if h, ok := b.imageContexts.getCache(imageSource.id, origPath); ok { if h, ok := b.imageSources.getCache(imageSource.Image().ImageID(), origPath); ok {
copyInfos[0].hash = h.(string) copyInfos[0].hash = h.(string)
return copyInfos, nil return copyInfos, nil
} }
@ -473,7 +473,7 @@ func (b *Builder) calcCopyInfo(cmdName, origPath string, allowLocalDecompression
hasher.Write([]byte(strings.Join(subfiles, ","))) hasher.Write([]byte(strings.Join(subfiles, ",")))
copyInfos[0].hash = "dir:" + hex.EncodeToString(hasher.Sum(nil)) copyInfos[0].hash = "dir:" + hex.EncodeToString(hasher.Sum(nil))
if imageSource != nil { if imageSource != nil {
b.imageContexts.setCache(imageSource.id, origPath, copyInfos[0].hash) b.imageSources.setCache(imageSource.Image().ImageID(), origPath, copyInfos[0].hash)
} }
return copyInfos, nil return copyInfos, nil
@ -501,7 +501,7 @@ func (b *Builder) probeCache(dispatchState *dispatchState, runConfig *container.
fmt.Fprint(b.Stdout, " ---> Using cache\n") fmt.Fprint(b.Stdout, " ---> Using cache\n")
logrus.Debugf("[BUILDER] Use cached version: %s", runConfig.Cmd) logrus.Debugf("[BUILDER] Use cached version: %s", runConfig.Cmd)
dispatchState.imageID = string(cache) dispatchState.imageID = string(cache)
b.imageContexts.update(dispatchState.imageID, runConfig) b.buildStages.update(dispatchState.imageID, runConfig)
return true, nil return true, nil
} }

View file

@ -66,15 +66,7 @@ func (m *MockBackend) CopyOnBuild(containerID string, destPath string, srcRoot s
return nil return nil
} }
func (m *MockBackend) HasExperimental() bool { func (m *MockBackend) GetImageAndReleasableLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (builder.Image, builder.ReleaseableLayer, error) {
return false
}
func (m *MockBackend) SquashImage(from string, to string) (string, error) {
return "", nil
}
func (m *MockBackend) GetImageAndLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (builder.Image, builder.ReleaseableLayer, error) {
if m.getImageFunc != nil { if m.getImageFunc != nil {
return m.getImageFunc(refOrID) return m.getImageFunc(refOrID)
} }
@ -112,6 +104,6 @@ func (l *mockLayer) Release() error {
return nil return nil
} }
func (l *mockLayer) Mount(_ string) (string, error) { func (l *mockLayer) Mount() (string, error) {
return "mountPath", nil return "mountPath", nil
} }

View file

@ -1,6 +1,7 @@
package daemon package daemon
import ( import (
"github.com/Sirupsen/logrus"
"github.com/docker/distribution/reference" "github.com/docker/distribution/reference"
"github.com/docker/docker/api/types" "github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/backend" "github.com/docker/docker/api/types/backend"
@ -15,54 +16,62 @@ import (
) )
type releaseableLayer struct { type releaseableLayer struct {
rwLayer layer.RWLayer layerStore layer.Store
release func(layer.RWLayer) error roLayer layer.Layer
mount func(string) (layer.RWLayer, error) rwLayer layer.RWLayer
} }
func (rl *releaseableLayer) Release() error { func (rl *releaseableLayer) Mount() (string, error) {
if rl.rwLayer == nil { if rl.roLayer == nil {
return nil return "", errors.New("can not mount an image with no root FS")
} }
rl.rwLayer.Unmount()
return rl.release(rl.rwLayer)
}
func (rl *releaseableLayer) Mount(imageID string) (string, error) {
var err error var err error
rl.rwLayer, err = rl.mount(imageID) mountID := stringid.GenerateRandomID()
rl.rwLayer, err = rl.layerStore.CreateRWLayer(mountID, rl.roLayer.ChainID(), nil)
if err != nil { if err != nil {
return "", errors.Wrap(err, "failed to create rwlayer") return "", errors.Wrap(err, "failed to create rwlayer")
} }
mountPath, err := rl.rwLayer.Mount("") return rl.rwLayer.Mount("")
if err != nil {
releaseErr := rl.release(rl.rwLayer)
if releaseErr != nil {
err = errors.Wrapf(err, "failed to release rwlayer: %s", releaseErr.Error())
}
return "", errors.Wrap(err, "failed to mount rwlayer")
}
return mountPath, err
} }
func (daemon *Daemon) getReleasableLayerForImage() *releaseableLayer { func (rl *releaseableLayer) Release() error {
mountFunc := func(imageID string) (layer.RWLayer, error) { rl.releaseRWLayer()
img, err := daemon.GetImage(imageID) return rl.releaseROLayer()
if err != nil { }
return nil, err
}
mountID := stringid.GenerateRandomID()
return daemon.layerStore.CreateRWLayer(mountID, img.RootFS.ChainID(), nil)
}
releaseFunc := func(rwLayer layer.RWLayer) error { func (rl *releaseableLayer) releaseRWLayer() error {
metadata, err := daemon.layerStore.ReleaseRWLayer(rwLayer) if rl.rwLayer == nil {
layer.LogReleaseMetadata(metadata) return nil
return err
} }
metadata, err := rl.layerStore.ReleaseRWLayer(rl.rwLayer)
layer.LogReleaseMetadata(metadata)
if err != nil {
logrus.Errorf("Failed to release RWLayer: %s", err)
}
return err
}
return &releaseableLayer{mount: mountFunc, release: releaseFunc} func (rl *releaseableLayer) releaseROLayer() error {
if rl.roLayer == nil {
return nil
}
metadata, err := rl.layerStore.Release(rl.roLayer)
layer.LogReleaseMetadata(metadata)
return err
}
func newReleasableLayerForImage(img *image.Image, layerStore layer.Store) (builder.ReleaseableLayer, error) {
if img.RootFS.ChainID() == "" {
return nil, nil
}
// Hold a reference to the image layer so that it can't be removed before
// it is released
roLayer, err := layerStore.Get(img.RootFS.ChainID())
if err != nil {
return nil, errors.Wrapf(err, "failed to get layer for image %s", img.ImageID())
}
return &releaseableLayer{layerStore: layerStore, roLayer: roLayer}, nil
} }
// TODO: could this use the regular daemon PullImage ? // TODO: could this use the regular daemon PullImage ?
@ -75,7 +84,7 @@ func (daemon *Daemon) pullForBuilder(ctx context.Context, name string, authConfi
pullRegistryAuth := &types.AuthConfig{} pullRegistryAuth := &types.AuthConfig{}
if len(authConfigs) > 0 { if len(authConfigs) > 0 {
// The request came with a full auth config file, we prefer to use that // The request came with a full auth config, use it
repoInfo, err := daemon.RegistryService.ResolveRepository(ref) repoInfo, err := daemon.RegistryService.ResolveRepository(ref)
if err != nil { if err != nil {
return nil, err return nil, err
@ -91,16 +100,23 @@ func (daemon *Daemon) pullForBuilder(ctx context.Context, name string, authConfi
return daemon.GetImage(name) return daemon.GetImage(name)
} }
// GetImageAndLayer returns an image and releaseable layer for a reference or ID // GetImageAndReleasableLayer returns an image and releaseable layer for a reference or ID.
func (daemon *Daemon) GetImageAndLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (builder.Image, builder.ReleaseableLayer, error) { // Every call to GetImageAndReleasableLayer MUST call releasableLayer.Release() to prevent
// leaking of layers.
func (daemon *Daemon) GetImageAndReleasableLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (builder.Image, builder.ReleaseableLayer, error) {
if !opts.ForcePull { if !opts.ForcePull {
image, _ := daemon.GetImage(refOrID) image, _ := daemon.GetImage(refOrID)
// TODO: shouldn't we error out if error is different from "not found" ? // TODO: shouldn't we error out if error is different from "not found" ?
if image != nil { if image != nil {
return image, daemon.getReleasableLayerForImage(), nil layer, err := newReleasableLayerForImage(image, daemon.layerStore)
return image, layer, err
} }
} }
image, err := daemon.pullForBuilder(ctx, refOrID, opts.AuthConfig, opts.Output) image, err := daemon.pullForBuilder(ctx, refOrID, opts.AuthConfig, opts.Output)
return image, daemon.getReleasableLayerForImage(), err if err != nil {
return nil, nil, err
}
layer, err := newReleasableLayerForImage(image, daemon.layerStore)
return image, layer, err
} }