Merge pull request #5548 from kunalkushwaha/image-prune

image prune skips images with child images.

2 files changed, 38 insertions, 8 deletions

diff --git a/libpod/image/image.go b/libpod/image/image.go
index 80cc6f15a..7198a42a3 100644
--- a/libpod/image/image.go
+++ b/libpod/image/image.go
@@ -32,10 +32,10 @@ import (
 	"github.com/containers/libpod/pkg/registries"
 	"github.com/containers/libpod/pkg/util"
 	"github.com/containers/storage"
-	"github.com/opencontainers/go-digest"
+	digest "github.com/opencontainers/go-digest"
 	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
 	ociv1 "github.com/opencontainers/image-spec/specs-go/v1"
-	"github.com/opentracing/opentracing-go"
+	opentracing "github.com/opentracing/opentracing-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -847,6 +847,26 @@ func (i *Image) Dangling() bool {
 	return len(i.Names()) == 0
 }
 
+// Intermediate returns true if the image is cache or intermediate image.
+// Cache image has parent and child.
+func (i *Image) Intermediate(ctx context.Context) (bool, error) {
+	parent, err := i.IsParent(ctx)
+	if err != nil {
+		return false, err
+	}
+	if !parent {
+		return false, nil
+	}
+	img, err := i.GetParent(ctx)
+	if err != nil {
+		return false, err
+	}
+	if img != nil {
+		return true, nil
+	}
+	return false, nil
+}
+
 // Labels returns the image's labels
 func (i *Image) Labels(ctx context.Context) (map[string]string, error) {
 	imgInspect, err := i.imageInspectInfo(ctx)
diff --git a/libpod/image/prune.go b/libpod/image/prune.go
index 3afff22af..3b4ea74c4 100644
--- a/libpod/image/prune.go
+++ b/libpod/image/prune.go
@@ -57,7 +57,7 @@ func generatePruneFilterFuncs(filter, filterValue string) (ImageFilter, error) {
 }
 
 // GetPruneImages returns a slice of images that have no names/unused
-func (ir *Runtime) GetPruneImages(all bool, filterFuncs []ImageFilter) ([]*Image, error) {
+func (ir *Runtime) GetPruneImages(ctx context.Context, all bool, filterFuncs []ImageFilter) ([]*Image, error) {
 	var (
 		pruneImages []*Image
 	)
@@ -74,10 +74,6 @@ func (ir *Runtime) GetPruneImages(all bool, filterFuncs []ImageFilter) ([]*Image
 			}
 		}
 
-		if len(i.Names()) == 0 {
-			pruneImages = append(pruneImages, i)
-			continue
-		}
 		if all {
 			containers, err := i.Containers()
 			if err != nil {
@@ -85,8 +81,22 @@ func (ir *Runtime) GetPruneImages(all bool, filterFuncs []ImageFilter) ([]*Image
 			}
 			if len(containers) < 1 {
 				pruneImages = append(pruneImages, i)
+				continue
 			}
 		}
+
+		//skip the cache or intermediate images
+		intermediate, err := i.Intermediate(ctx)
+		if err != nil {
+			return nil, err
+		}
+		if intermediate {
+			continue
+		}
+
+		if i.Dangling() {
+			pruneImages = append(pruneImages, i)
+		}
 	}
 	return pruneImages, nil
 }
@@ -111,7 +121,7 @@ func (ir *Runtime) PruneImages(ctx context.Context, all bool, filter []string) (
 		filterFuncs = append(filterFuncs, generatedFunc)
 	}
 
-	pruneImages, err := ir.GetPruneImages(all, filterFuncs)
+	pruneImages, err := ir.GetPruneImages(ctx, all, filterFuncs)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to get images to prune")
 	}