[content-service] Make prebuild initializer more robust

components/content-service/pkg/git/git.go

@@ -348,13 +348,6 @@ func (c *Client) Clone(ctx context.Context) (err error) {
 	return c.Git(ctx, "clone", args...)
 }
 
-// Fetch runs git fetch and prunes remote-tracking references as well as ALL LOCAL TAGS.
-func (c *Client) Fetch(ctx context.Context) (err error) {
-	// we need to fetch with pruning to avoid issues like github.com/gitpod-io/gitpod/issues/7561.
-	// See https://git-scm.com/docs/git-fetch#Documentation/git-fetch.txt---prune for more details.
-	return c.Git(ctx, "fetch", "-p", "-P", "--tags", "-f")
-}
-
 // UpdateRemote performs a git fetch on the upstream remote URI
 func (c *Client) UpdateRemote(ctx context.Context) (err error) {
 	//nolint:staticcheck,ineffassign

components/content-service/pkg/initializer/git.go

@@ -188,7 +188,13 @@ func (ws *GitInitializer) realizeCloneTarget(ctx context.Context) (err error) {
 			ws.CloneTarget = defaultBranch
 		}
 
-		if err := ws.Git(ctx, "fetch", "--depth=1", "origin", ws.CloneTarget); err != nil {
+		// No need to prune here because we fetch the specific branch only. If we were to try and fetch everything,
+		// we might end up trying to fetch at tag/branch which has since been recreated. It's exactly the specific
+		// fetch wich prevents this situation.
+		//
+		// We don't recurse submodules because callers realizeCloneTarget() are expected to update submodules explicitly,
+		// and deal with any error appropriately (i.e. emit a warning rather than fail).
+		if err := ws.Git(ctx, "fetch", "--depth=1", "origin", "--recurse-submodules=no", ws.CloneTarget); err != nil {
 			log.WithError(err).WithField("remoteURI", ws.RemoteURI).WithField("branch", ws.CloneTarget).Error("Cannot fetch remote branch")
 			return err
 		}

components/content-service/pkg/initializer/prebuild.go

@@ -130,15 +130,14 @@ func runGitInit(ctx context.Context, gInit *GitInitializer) (err error) {
 		}
 		didStash := !strings.Contains(string(out), "No local changes to save")
 
-		err = gInit.Fetch(ctx)
-		err = checkGitStatus(err)
+		err = checkGitStatus(gInit.realizeCloneTarget(ctx))
 		if err != nil {
 			return xerrors.Errorf("prebuild initializer: %w", err)
 		}
 
-		err = gInit.realizeCloneTarget(ctx)
+		err = gInit.UpdateSubmodules(ctx)
 		if err != nil {
-			return xerrors.Errorf("prebuild initializer: %w", err)
+			log.WithError(err).Warn("error while updating submodules from prebuild initializer - continuing")
 		}
 
 		// If any of these cleanup operations fail that's no reason to fail ws initialization.