image_pull: repull when image ID (config digest) changed

Signed-off-by: Antonio Murdaca <runcom@redhat.com>
This commit is contained in:
Antonio Murdaca 2017-11-09 19:15:56 +01:00
parent 8a39d94a0d
commit 5488bfeb9e
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GPG Key ID: B2BEAD150DE936B9
2 changed files with 49 additions and 14 deletions

View File

@ -17,6 +17,7 @@ import (
"github.com/containers/image/types"
"github.com/containers/storage"
distreference "github.com/docker/distribution/reference"
digest "github.com/opencontainers/go-digest"
)
// ImageResult wraps a subset of information about an image: its ID, its names,
@ -25,6 +26,10 @@ type ImageResult struct {
ID string
Names []string
Size *uint64
// TODO(runcom): this is an hack for https://github.com/kubernetes-incubator/cri-o/pull/1136
// drop this when we have proper image IDs (as in, image IDs should be just
// the config blog digest which is stable across same images).
ConfigDigest digest.Digest
}
type indexInfo struct {
@ -47,6 +52,9 @@ type ImageServer interface {
ListImages(systemContext *types.SystemContext, filter string) ([]ImageResult, error)
// ImageStatus returns status of an image which matches the filter.
ImageStatus(systemContext *types.SystemContext, filter string) (*ImageResult, error)
// PrepareImage returns an Image where the config digest can be grabbed
// for further analysis. Call Close() on the resulting image.
PrepareImage(systemContext *types.SystemContext, imageName string, options *copy.Options) (types.Image, error)
// PullImage imports an image from the specified location.
PullImage(systemContext *types.SystemContext, imageName string, options *copy.Options) (types.ImageReference, error)
// RemoveImage deletes the specified image.
@ -146,14 +154,16 @@ func (svc *imageService) ImageStatus(systemContext *types.SystemContext, nameOrI
if err != nil {
return nil, err
}
defer img.Close()
size := imageSize(img)
img.Close()
return &ImageResult{
ID: image.ID,
Names: image.Names,
Size: size,
}, nil
res := &ImageResult{
ID: image.ID,
Names: image.Names,
Size: size,
ConfigDigest: img.ConfigInfo().Digest,
}
return res, nil
}
func imageSize(img types.Image) *uint64 {
@ -165,7 +175,7 @@ func imageSize(img types.Image) *uint64 {
}
func (svc *imageService) CanPull(imageName string, options *copy.Options) (bool, error) {
srcRef, err := svc.prepareImage(imageName, options)
srcRef, err := svc.prepareReference(imageName, options)
if err != nil {
return false, err
}
@ -182,9 +192,9 @@ func (svc *imageService) CanPull(imageName string, options *copy.Options) (bool,
return true, nil
}
// prepareImage creates an image reference from an image string and set options
// prepareReference creates an image reference from an image string and set options
// for the source context
func (svc *imageService) prepareImage(imageName string, options *copy.Options) (types.ImageReference, error) {
func (svc *imageService) prepareReference(imageName string, options *copy.Options) (types.ImageReference, error) {
if imageName == "" {
return nil, storage.ErrNotAnImage
}
@ -212,6 +222,18 @@ func (svc *imageService) prepareImage(imageName string, options *copy.Options) (
return srcRef, nil
}
func (svc *imageService) PrepareImage(systemContext *types.SystemContext, imageName string, options *copy.Options) (types.Image, error) {
if options == nil {
options = &copy.Options{}
}
srcRef, err := svc.prepareReference(imageName, options)
if err != nil {
return nil, err
}
return srcRef.NewImage(systemContext)
}
func (svc *imageService) PullImage(systemContext *types.SystemContext, imageName string, options *copy.Options) (types.ImageReference, error) {
policy, err := signature.DefaultPolicy(systemContext)
if err != nil {
@ -225,7 +247,7 @@ func (svc *imageService) PullImage(systemContext *types.SystemContext, imageName
options = &copy.Options{}
}
srcRef, err := svc.prepareImage(imageName, options)
srcRef, err := svc.prepareReference(imageName, options)
if err != nil {
return nil, err
}

View File

@ -6,6 +6,7 @@ import (
"github.com/containers/image/copy"
"github.com/containers/image/types"
"github.com/kubernetes-incubator/cri-o/pkg/storage"
"github.com/sirupsen/logrus"
"golang.org/x/net/context"
pb "k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
@ -67,11 +68,23 @@ func (s *Server) PullImage(ctx context.Context, req *pb.PullImageRequest) (*pb.P
}
// let's be smart, docker doesn't repull if image already exists.
_, err = s.StorageImageServer().ImageStatus(s.ImageContext(), img)
var storedImage *storage.ImageResult
storedImage, err = s.StorageImageServer().ImageStatus(s.ImageContext(), img)
if err == nil {
logrus.Debugf("image %s already in store, skipping pull", img)
pulled = img
break
tmpImg, err := s.StorageImageServer().PrepareImage(s.ImageContext(), img, options)
if err == nil {
tmpImgConfigDigest := tmpImg.ConfigInfo().Digest
if tmpImgConfigDigest.String() == "" {
// this means we are playing with a schema1 image, in which
// case, we're going to repull the image in any case
logrus.Debugf("image config digest is empty, re-pulling image")
} else if tmpImgConfigDigest.String() == storedImage.ConfigDigest.String() {
logrus.Debugf("image %s already in store, skipping pull", img)
pulled = img
break
}
}
logrus.Debugf("image in store has different ID, re-pulling %s", img)
}
_, err = s.StorageImageServer().PullImage(s.ImageContext(), img, options)