filter added to image pruge command.

filter option accepts two filters.
- label
- until
label supports "label=value" or "label=key=value" format
until supports all golang compatible time/duration formats.

Signed-off-by: Kunal Kushwaha <kunal.kushwaha@gmail.com>

2 files changed, 80 insertions, 4 deletions

diff --git a/libpod/image/image.go b/libpod/image/image.go
index c912ac2ca..5871c8a57 100644
--- a/libpod/image/image.go
+++ b/libpod/image/image.go
@@ -74,6 +74,11 @@ type InfoImage struct {
 	Layers []LayerInfo
 }
 
+// ImageFilter is a function to determine whether a image is included
+// in command output. Images to be outputted are tested using the function.
+// A true return will include the image, a false return will exclude it.
+type ImageFilter func(*Image) bool //nolint
+
 // ErrRepoTagNotFound is the error returned when the image id given doesn't match a rep tag in store
 var ErrRepoTagNotFound = stderrors.New("unable to match user input to any specific repotag")
 
diff --git a/libpod/image/prune.go b/libpod/image/prune.go
index 006cbdf22..f5be8ed50 100644
--- a/libpod/image/prune.go
+++ b/libpod/image/prune.go
@@ -2,23 +2,78 @@ package image
 
 import (
 	"context"
+	"strings"
+	"time"
 
 	"github.com/containers/libpod/libpod/events"
+	"github.com/containers/libpod/pkg/timetype"
 	"github.com/containers/storage"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
+func generatePruneFilterFuncs(filter, filterValue string) (ImageFilter, error) {
+	switch filter {
+	case "label":
+		var filterArray = strings.SplitN(filterValue, "=", 2)
+		var filterKey = filterArray[0]
+		if len(filterArray) > 1 {
+			filterValue = filterArray[1]
+		} else {
+			filterValue = ""
+		}
+		return func(i *Image) bool {
+			labels, err := i.Labels(context.Background())
+			if err != nil {
+				return false
+			}
+			for labelKey, labelValue := range labels {
+				if labelKey == filterKey && ("" == filterValue || labelValue == filterValue) {
+					return true
+				}
+			}
+			return false
+		}, nil
+
+	case "until":
+		ts, err := timetype.GetTimestamp(filterValue, time.Now())
+		if err != nil {
+			return nil, err
+		}
+		seconds, nanoseconds, err := timetype.ParseTimestamps(ts, 0)
+		if err != nil {
+			return nil, err
+		}
+		until := time.Unix(seconds, nanoseconds)
+		return func(i *Image) bool {
+			if !until.IsZero() && i.Created().After((until)) {
+				return true
+			}
+			return false
+		}, nil
+
+	}
+	return nil, nil
+}
+
 // GetPruneImages returns a slice of images that have no names/unused
-func (ir *Runtime) GetPruneImages(all bool) ([]*Image, error) {
+func (ir *Runtime) GetPruneImages(all bool, filterFuncs []ImageFilter) ([]*Image, error) {
 	var (
 		pruneImages []*Image
 	)
+
 	allImages, err := ir.GetRWImages()
 	if err != nil {
 		return nil, err
 	}
 	for _, i := range allImages {
+		// filter the images based on this.
+		for _, filterFunc := range filterFuncs {
+			if !filterFunc(i) {
+				continue
+			}
+		}
+
 		if len(i.Names()) == 0 {
 			pruneImages = append(pruneImages, i)
 			continue
@@ -38,9 +93,25 @@ func (ir *Runtime) GetPruneImages(all bool) ([]*Image, error) {
 
 // PruneImages prunes dangling and optionally all unused images from the local
 // image store
-func (ir *Runtime) PruneImages(ctx context.Context, all bool) ([]string, error) {
-	var prunedCids []string
-	pruneImages, err := ir.GetPruneImages(all)
+func (ir *Runtime) PruneImages(ctx context.Context, all bool, filter []string) ([]string, error) {
+	var (
+		prunedCids  []string
+		filterFuncs []ImageFilter
+	)
+	for _, f := range filter {
+		filterSplit := strings.SplitN(f, "=", 2)
+		if len(filterSplit) < 2 {
+			return nil, errors.Errorf("filter input must be in the form of filter=value: %s is invalid", f)
+		}
+
+		generatedFunc, err := generatePruneFilterFuncs(filterSplit[0], filterSplit[1])
+		if err != nil {
+			return nil, errors.Wrapf(err, "invalid filter")
+		}
+		filterFuncs = append(filterFuncs, generatedFunc)
+	}
+
+	pruneImages, err := ir.GetPruneImages(all, filterFuncs)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to get images to prune")
 	}