Restic-REST-Server: Accessing /metrics impossible with auth enabled?

The documentation is a bit vague on the point, but I expected to be able to add a user called ‘metrics’ to my htpasswd file and then use metrics // the_password_i_assigned to access the /metrics endpoint. But that doesn’t seem to work; I get access denied. Regular user credentials in the htpasswd file work to access their repositories, and adding --prometheus-no-auth allows me to access /metrics, so it is working. What else do I need to do to get authenticated metrics access to work ? Using the latest restic-rest build via Docker/Podman.

The following works for me (using rest-server 0.12.1):

$ htpasswd -B -b testrepo/.htpasswd metrics password
$ rest-server --listen localhost:12345 --path testrepo --private-repos --prometheus
$ curl -v -X GET -u metrics:password http://localhost:12345/metrics

Without --private-repos you can use any valid rest-server user.

My bad. Like I said in the chat, it turned out that Firefox was doing something wonky - using an URL like, cURL/wget worked just fine, while Firefox reported ‘Unauthorized’