Hi all,

I want to run Prometheus on a subpath, using a reverse proxy. That is when a client requestshttp://mydomain/foo/query, this is routed to 127.0.0.1:9090/query by the reverse proxy.

I am aware of the --web.external-url. However, surprisingly, Prometheus works out of the box without setting that flag.

I have NGINX configured like this

location /foo/ {
        proxy_http_version 1.1;
        proxy_pass http://127.0.0.1:9090/;
        proxy_set_header Host $host;
}

When I access http://mydomain/foo/query, all the links in the page are not to e.g. /alerts but /foo/alerts.

How could Prometheus know how to adjust the URLs? The request from NGINX to Prometheus does not contain any special header like X-Forwarded-Prefix