add cache images logic

cmd/docker-buildx/config.go

@@ -207,6 +207,12 @@ func settingsFlags(settings *plugin.Settings) []cli.Flag {
 			Usage:       "cache destination for the build cache",
 			Destination: &settings.Build.CacheTo,
 		},
+		&cli.StringSliceFlag{
+			Name:        "cache-images",
+			EnvVars:     []string{"PLUGIN_CACHE_IMAGES"},
+			Usage:       "list of images to use for build cache. applies both to and from flags for each image",
+			Destination: &settings.Build.CacheImages,
+		},
 		&cli.BoolFlag{
 			Name:        "pull-image",
 			EnvVars:     []string{"PLUGIN_PULL_IMAGE"},

plugin/docker.go

@@ -84,6 +84,10 @@ func commandBuild(build Build, dryrun bool) *exec.Cmd {
 	if build.CacheTo != "" {
 		args = append(args, "--cache-to", build.CacheTo)
 	}
+	for _, arg := range build.CacheImages.Value() {
+		args = append(args, "--cache-from", arg)
+		args = append(args, string("--cache-to=type=registry,ref="+arg+",mode=max,image-manifest=true,oci-mediatypes=true"))
+	}
 	for _, arg := range build.ArgsEnv.Value() {
 		addProxyValue(&build, arg)
 	}

plugin/impl.go

@@ -74,6 +74,7 @@ type Build struct {
 	Pull            bool            // Docker build pull
 	CacheFrom       string          // Docker build cache-from
 	CacheTo         string          // Docker build cache-to
+	CacheImages     cli.StringSlice // Docker build cache images
 	Compress        bool            // Docker build compress
 	Repo            cli.StringSlice // Docker build repository
 	NoCache         bool            // Docker build no-cache