feat: add mutable tags support for image synchronization

Author: kamushadenes

config/sync.go

@@ -37,6 +37,9 @@ var (
 				"targets": []string{
 					"docker.io/library/ubuntu",
 				},
+				"mutableTags": []string{
+					"latest",
+				},
 			},
 		}),
 		WithValidImages())

internal/sync/images.go

@@ -199,7 +199,7 @@ func SyncImage(ctx context.Context, image *structs.Image) error {
 			}
 
 			for _, dst := range image.Targets {
-				if slices.Contains(dstTags, fmt.Sprintf("%s:%s", dst, tag)) {
+				if !slices.Contains(image.MutableTags, tag) && slices.Contains(dstTags, fmt.Sprintf("%s:%s", dst, tag)) {
 					log.Info().
 						Str("image", image.Source).
 						Str("tag", tag).

structs/image.go

@@ -7,9 +7,10 @@ import (
 )
 
 type Image struct {
-	Source  string                   `json:"source" yaml:"source"`
-	Targets []string                 `json:"targets" yaml:"targets"`
-	Auths   map[string]remote.Option `json:"-" yaml:"-"`
+	Source      string                   `json:"source" yaml:"source"`
+	Targets     []string                 `json:"targets" yaml:"targets"`
+	MutableTags []string                 `json:"mutableTags" yaml:"mutableTags"`
+	Auths       map[string]remote.Option `json:"-" yaml:"-"`
 }
 
 func (i *Image) GetSource() string {