Merge pull request #891 from cvgw/u/cvgw/last-cachekey-or-base-image-…

…digest

Final cachekey for stage

pkg/executor/build.go

@@ -54,19 +54,21 @@ const emptyTarSize = 1024
 
 // stageBuilder contains all fields necessary to build one stage of a Dockerfile
 type stageBuilder struct {
- stage config.KanikoStage
- image v1.Image
- cf *v1.ConfigFile
- snapshotter *snapshot.Snapshotter
- baseImageDigest string
- opts *config.KanikoOptions
- cmds []commands.DockerCommand
- args *dockerfile.BuildArgs
- crossStageDeps map[int][]string
+ stage config.KanikoStage
+ image v1.Image
+ cf *v1.ConfigFile
+ snapshotter *snapshot.Snapshotter
+ baseImageDigest string
+ finalCacheKey string
+ opts *config.KanikoOptions
+ cmds []commands.DockerCommand
+ args *dockerfile.BuildArgs
+ crossStageDeps map[int][]string
+ digestToCacheKeyMap map[string]string
 }
 
 // newStageBuilder returns a new type stageBuilder which contains all the information required to build the stage
-func newStageBuilder(opts *config.KanikoOptions, stage config.KanikoStage, crossStageDeps map[int][]string) (*stageBuilder, error) {
+func newStageBuilder(opts *config.KanikoOptions, stage config.KanikoStage, crossStageDeps map[int][]string, dcm map[string]string) (*stageBuilder, error) {
  sourceImage, err := util.RetrieveSourceImage(stage, opts)
  if err != nil {
  return nil, err
@@ -93,13 +95,14 @@ func newStageBuilder(opts *config.KanikoOptions, stage config.KanikoStage, cross
  return nil, err
  }
  s := &stageBuilder{
- stage: stage,
- image: sourceImage,
- cf: imageConfig,
- snapshotter: snapshotter,
- baseImageDigest: digest.String(),
- opts: opts,
- crossStageDeps: crossStageDeps,
+ stage: stage,
+ image: sourceImage,
+ cf: imageConfig,
+ snapshotter: snapshotter,
+ baseImageDigest: digest.String(),
+ opts: opts,
+ crossStageDeps: crossStageDeps,
+ digestToCacheKeyMap: dcm,
  }
 
  for _, cmd := range s.stage.Commands {
@@ -163,6 +166,7 @@ func (s *stageBuilder) optimize(compositeKey CompositeCache, cfg v1.Config) erro
  if err != nil {
  return err
  }
+ s.finalCacheKey = ck
  if command.ShouldCacheOutput() {
  img, err := layerCache.RetrieveLayer(ck)
  if err != nil {
@@ -190,7 +194,12 @@ func (s *stageBuilder) optimize(compositeKey CompositeCache, cfg v1.Config) erro
 
 func (s *stageBuilder) build() error {
  // Set the initial cache key to be the base image digest, the build args and the SrcContext.
- compositeKey := NewCompositeCache(s.baseImageDigest)
+ var compositeKey *CompositeCache
+ if cacheKey, ok := s.digestToCacheKeyMap[s.baseImageDigest]; ok {
+ compositeKey = NewCompositeCache(cacheKey)
+ } else {
+ compositeKey = NewCompositeCache(s.baseImageDigest)
+ }
  compositeKey.AddKey(s.opts.BuildArgs...)
 
  // Apply optimizations to the instructions.
@@ -422,6 +431,7 @@ func CalculateDependencies(opts *config.KanikoOptions) (map[int][]string, error)
 // DoBuild executes building the Dockerfile
 func DoBuild(opts *config.KanikoOptions) (v1.Image, error) {
  t := timing.Start("Total Build Time")
+ digestToCacheKeyMap := make(map[string]string)
  // Parse dockerfile and unpack base image to root
  stages, err := dockerfile.Stages(opts)
  if err != nil {
@@ -442,7 +452,7 @@ func DoBuild(opts *config.KanikoOptions) (v1.Image, error) {
  logrus.Infof("Built cross stage deps: %v", crossStageDependencies)
 
  for index, stage := range stages {
- sb, err := newStageBuilder(opts, stage, crossStageDependencies)
+ sb, err := newStageBuilder(opts, stage, crossStageDependencies, digestToCacheKeyMap)
  if err != nil {
  return nil, err
  }
@@ -454,6 +464,11 @@ func DoBuild(opts *config.KanikoOptions) (v1.Image, error) {
  if err != nil {
  return nil, err
  }
+ d, err := sourceImage.Digest()
+ if err != nil {
+ return nil, err
+ }
+ digestToCacheKeyMap[d.String()] = sb.finalCacheKey
  if stage.Final {
  sourceImage, err = mutate.CreatedAt(sourceImage, v1.Time{Time: time.Now()})
  if err != nil {