fix: downloading files from a snapshot can fail if repoID has changed

internal/api/downloadhandler.go

@@ -54,7 +54,16 @@ func NewDownloadHandler(oplog *oplog.OpLog, orchestrator *orchestrator.Orchestra
 }
 
 func handleIndexSnapshotDownload(w http.ResponseWriter, r *http.Request, orchestrator *orchestrator.Orchestrator, op *v1.Operation, indexOp *v1.Operation_OperationIndexSnapshot, filePath string) {
-	repoCfg, err := orchestrator.GetRepo(op.RepoId)
+	// Resolve the repo by GUID; the op may have been recorded under a repo id
+	// the repo is no longer configured with.
+	repoID := op.RepoId
+	if op.RepoGuid != "" {
+		if byGuid, err := orchestrator.GetRepoByGUID(op.RepoGuid); err == nil {
+			repoID = byGuid.Id
+		}
+	}
+
+	repoCfg, err := orchestrator.GetRepo(repoID)
 	if err != nil {
 		http.Error(w, "error getting repo", http.StatusInternalServerError)
 		return
@@ -65,7 +74,7 @@ func handleIndexSnapshotDownload(w http.ResponseWriter, r *http.Request, orchest
 		return
 	}
 
-	repo, err := orchestrator.GetRepoOrchestrator(op.RepoId)
+	repo, err := orchestrator.GetRepoOrchestrator(repoID)
 	if err != nil {
 		http.Error(w, "error getting repo", http.StatusInternalServerError)
 		return

internal/orchestrator/orchestrator.go

@@ -355,6 +355,17 @@ func (o *Orchestrator) GetRepo(repoID string) (*v1.Repo, error) {
 	return repo, nil
 }
 
+func (o *Orchestrator) GetRepoByGUID(guid string) (*v1.Repo, error) {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+
+	repo := config.FindRepoByGUID(o.config, guid)
+	if repo == nil {
+		return nil, fmt.Errorf("get repo by guid %q: %w", guid, ErrRepoNotFound)
+	}
+	return repo, nil
+}
+
 func (o *Orchestrator) GetPlan(planID string) (*v1.Plan, error) {
 	o.mu.Lock()
 	defer o.mu.Unlock()