update zos worker to include v4 versions

pkg/upgrade/README.md

@@ -2,9 +2,11 @@
 
 The upgrade module is responsible to keep a zos node always up to date.
 
-It checks the hub for new releases of zos packages.
+It checks the hub for new releases of zos packages. Also check version and `safe_to_upgrade` flag from the chain.
 
-If a new release is available, it will then update the packages and restart the updated module with the new binaries if required.
+If `safe_to_upgrade` is set to `false` and a new release is available then it will only update the [configured farms](https://github.com/threefoldtech/zos-config/blob/main/config.schema.json#L49)
+
+If `safe_to_upgrade` is set to `true` and a new release is available, it will then update the packages and restart the updated module with the new binaries if required.
 
 ## Usage
 

tools/zos-update-worker/internal/update_worker.go

@@ -129,42 +129,50 @@ func (w *Worker) updateZosVersion(network Network, manager client.Manager) error
 		return fmt.Errorf("failed to get dst relative path to src: %w", err)
 	}
 
+	//zos
 	zosCurrent := fmt.Sprintf("%v/.tag-%v", w.src, chainVersion.Version)
 	zosLatest := fmt.Sprintf("%v/%v", w.dst, network)
+	// zos light
+	zosLightCurrent := fmt.Sprintf("%v/.tag-%v", w.src, chainVersion.Version)
+	zosLightLatest := fmt.Sprintf("%v/%v-v4", w.dst, network)
 	// the link is like zosCurrent but it has the path relative from the symlink
 	// point of view (so relative to the symlink, how to reach zosCurrent)
 	// hence the link is instead used in all calls to symlink
-	link := fmt.Sprintf("%v/.tag-%v", path, chainVersion.Version)
+	zosLink := fmt.Sprintf("%v/.tag-%v", path, chainVersion.Version)
+	zosLightLink := fmt.Sprintf("%v/.tag-%v", path, chainVersion.Version)
 
-	// check if current exists
-	if _, err := os.Lstat(zosCurrent); err != nil {
+	// update links for both zos and zoslight
+	if err = w.updateLink(zosCurrent, zosLatest, zosLink); err != nil {
 		return err
 	}
+	return w.updateLink(zosLightCurrent, zosLightLatest, zosLightLink)
+}
 
+func (w *Worker) updateLink(current string, latest string, link string) error {
 	// check if symlink exists
-	dst, err := os.Readlink(zosLatest)
+	dst, err := os.Readlink(latest)
 
 	// if no symlink, then create it
 	if os.IsNotExist(err) {
-		log.Info().Str("from", zosLatest).Str("to", zosCurrent).Msg("linking")
-		return os.Symlink(link, zosLatest)
+		log.Info().Str("from", latest).Str("to", current).Msg("linking")
+		return os.Symlink(link, latest)
 	} else if err != nil {
 		return err
 	}
 
 	// check if symlink is valid and exists
-	if filepath.Base(dst) == filepath.Base(zosCurrent) {
-		log.Debug().Msgf("symlink %v to %v already exists", zosCurrent, zosLatest)
+	if filepath.Base(dst) == filepath.Base(current) {
+		log.Debug().Msgf("symlink %v to %v already exists", current, latest)
 		return nil
 	}
 
 	// remove symlink if it is not valid and exists
-	if err := os.Remove(zosLatest); err != nil {
+	if err := os.Remove(latest); err != nil {
 		return err
 	}
 
-	log.Info().Str("from", zosLatest).Str("to", zosCurrent).Msg("linking")
-	return os.Symlink(link, zosLatest)
+	log.Info().Str("from", latest).Str("to", current).Msg("linking")
+	return os.Symlink(link, latest)
 }
 
 // UpdateWithInterval updates the latest zos flist for a specific network with the updated zos version