Fix permissions on cache when --no-push is set (#1445)

pkg/executor/push.go

@@ -102,14 +102,17 @@ var (
 // CheckPushPermissions checks that the configured credentials can be used to
 // push to every specified destination.
 func CheckPushPermissions(opts *config.KanikoOptions) error {
+ var targets = opts.Destinations
+ // When no push is set, whe want to check permissions for the cache repo
+ // instead of the destinations
  if opts.NoPush {
- return nil
+ targets = []string{opts.CacheRepo}
  }
 
  checked := map[string]bool{}
  _, err := fs.Stat(DockerConfLocation())
  dockerConfNotExists := os.IsNotExist(err)
- for _, destination := range opts.Destinations {
+ for _, destination := range targets {
  destRef, err := name.NewTag(destination, name.WeakValidation)
  if err != nil {
  return errors.Wrap(err, "getting tag for destination")