Reverse_proxy subfolder rewrite

[tcurdt (Torsten Curdt)]

Continuing the discussion from Attempting to reverse proxy to a folder w/ Caddy 2:

I am using the docker image caddy:2.3.0-alpine.

The accepted solution from the previous discussion is this

@Whitestrake

  # Prepend '/dps'
  rewrite /dps{uri}

  # Send upstream
  reverse_proxy https://upstream

but I am getting Error during parsing: Wrong argument count or unexpected line ending after 'rewrite' when trying this

  bar.foo.com {
    header Cache-Control max-age=3600
    rewrite /some/folder{uri}
    reverse_proxy {
      to https://other.com
    }
  }

And fair enough - looking at the docs it seems like rewrite needs a 2nd arg. So I changed it to:

bar.foo.com {
    header Cache-Control max-age=3600
    rewrite * /some/folder{uri}
    reverse_proxy {
      to https://other.com
    }
  }

But now while a curl works just fine curl https://other.com/some/folder/FOO on the upstream, caddy is giving a 421 status error for curl https://bar.foo.com/FOO.

I don’t quite understand why. Any thoughts on how to debug this?

[francislavoie]

I answered this on Discord

@tcurdt if your upstream is expecting to see other.com as the Host/SNI, then you need to add this to your reverse_proxy options:

header_up Host {http.reverse_proxy.upstream.hostport}

reverse_proxy (Caddyfile directive) - Caddy Documentation

[tcurdt (Torsten Curdt)]

Indeed you did Thanks again!