Basic auth in monitor with caddy + authelia

[ckgxrg-salt]

Installed glance on nixos from nixpkgs, version 0.8.3

I set up basic-auth options under monitor widgets as described in the docs, and recently switched from nginx to caddy.

With nginx, everything works smoothly; but with caddy, authelia reports unauthorized for user "anonymous" which means the credentials are not received.
I found some answers saying that caddy will not automatically handle "Authorization' headers, so I added relevant header_up like this:

forward_auth authelia {
  uri /api/authz/forward-auth
  copy_headers Remote-User Remote-Groups Remote-Email Remote-Name
  header_up Proxy-Authorization {header.authorization}
}
reverse_proxy glance

With this config, I can curl -u username:password to my endpoints and caddy reports correct "Authorization" headers in the log, and authelia can normally grant access.

"headers":{"Authorization":["REDACTED"],"User-Agent":["curl/8.13.0"],"Accept":["*/*"]}

But with glance, caddy reports this:

"headers":{"Accept-Encoding":["gzip"],"User-Agent":["Go-http-client/2.0"]}

The "Authorization" header is missing, and the credentials are not received.