feat: add flag to disable pushing cache (#2038)

pkg/executor/build.go

@@ -420,7 +420,7 @@ func (s *stageBuilder) build() error {
 				logrus.Debugf("build: cache key for command %v %v", command.String(), ck)
 
 				// Push layer to cache (in parallel) now along with new config file
-				if command.ShouldCacheOutput() {
+				if command.ShouldCacheOutput() && ! s.opts.NoPushCache {
 					cacheGroup.Go(func() error {
 						return s.pushLayerToCache(s.opts, ck, tarPath, command.String())
 					})

pkg/executor/push.go

@@ -78,9 +78,13 @@ var (
 // push to every specified destination.
 func CheckPushPermissions(opts *config.KanikoOptions) error {
 	targets := opts.Destinations
-	// When no push is set, whe want to check permissions for the cache repo
+	// When no push and no push cache are set, we don't need to check permissions
+	if opts.NoPush && opt.noPushCache {
+		targets = []string{}
+	}
+	// When no push is set, we want to check permissions for the cache repo
 	// instead of the destinations
-	if opts.NoPush {
+	else if opts.NoPush && ! opt.noPushCache {
 		targets = []string{opts.CacheRepo}
 	}