fix hard-coded timeout and error panic in API archive download endpoint (#20925)

* fix hard-coded timeout and error panic in API archive download endpoint

This commit updates the `GET /api/v1/repos/{owner}/{repo}/archive/{archive}`
endpoint which prior to this PR had a couple of issues.

1. The endpoint had a hard-coded 20s timeout for the archiver to complete after
   which a 500 (Internal Server Error) was returned to client. For a scripted
   API client there was no clear way of telling that the operation timed out and
   that it should retry.

2. Whenever the timeout _did occur_, the code used to panic. This was caused by
   the API endpoint "delegating" to the same call path as the web, which uses a
   slightly different way of reporting errors (HTML rather than JSON for
   example).

   More specifically, `api/v1/repo/file.go#GetArchive` just called through to
   `web/repo/repo.go#Download`, which expects the `Context` to have a `Render`
   field set, but which is `nil` for API calls. Hence, a `nil` pointer error.

The code addresses (1) by dropping the hard-coded timeout. Instead, any
timeout/cancelation on the incoming `Context` is used.

The code addresses (2) by updating the API endpoint to use a separate call path
for the API-triggered archive download. This avoids producing HTML-errors on
errors (it now produces JSON errors).

Signed-off-by: Peter Gardfjäll <peter.gardfjall.work@gmail.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/cmd/migrate_storage.go b/cmd/migrate_storage.go
index f11cf9b11f..a283f91401 100644
--- a/cmd/migrate_storage.go
+++ b/cmd/migrate_storage.go
@@ -112,11 +112,8 @@ func migrateRepoAvatars(ctx context.Context, dstStorage storage.ObjectStorage) e
 
 func migrateRepoArchivers(ctx context.Context, dstStorage storage.ObjectStorage) error {
 	return db.IterateObjects(ctx, func(archiver *repo_model.RepoArchiver) error {
-		p, err := archiver.RelativePath()
-		if err != nil {
-			return err
-		}
-		_, err = storage.Copy(dstStorage, p, storage.RepoArchives, p)
+		p := archiver.RelativePath()
+		_, err := storage.Copy(dstStorage, p, storage.RepoArchives, p)
 		return err
 	})
 }