Reverse_proxy with custom header_up

[5knnbdwm]

1. Caddy version (caddy version):

v2.2.0-rc.1

2. How I run Caddy:

a. System environment:

CentOS SELinux 8 x64

b. Command:

caddy start;
caddy reload;

c. Service/unit/compose file:

N/A

d. My complete Caddyfile or JSON config:

tableau.soeller.dev {
        route / {
                respond "Hello, world!"
        }
        route /tableau/* {
                uri * strip_prefix /tableau
                reverse_proxy * http://217.79.180.190:8080 {
                        header_up REMOTE_ADDR {http.request.host}
                        header_up X-Forwarded-For {http.request.remote_host}
                        header_up Host {http.request.host}
                        header_up X-Forwarded-Host {http.request.remote_host}
                        header_up X-Forwarded-Proto {http.request.scheme}
                }
        }
        log {
                output file /root/caddy2.log {
                        roll_local_time true
                }
                format json
        }
}

3. The problem I’m having:

I’m trying to put tableau server behind route on my domain. When doing it the way I did it in my Caddyfile and direct to tableau.my_domain/tableau I only receive a white screen with a 200 response. What I want to receive is the signing page for tableau.

My problem is that I do not know how exactly I have to set up the additional header that tableau requires.

link further down

4. Error messages and/or full log output:

{
  "level": "info",
  "ts": 1613061634.4891918,
  "logger": "http.log.access.log0",
  "msg": "handled request",
  "request": {
    "remote_addr": "82.102.16.198:62324",
    "proto": "HTTP/2.0",
    "method": "GET",
    "host": "tableau.soeller.dev",
    "uri": "/tableau",
    "headers": {
      "Cookie": [
        "workgroup_session_id=null"
      ],
      "Accept": [
        "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
      ],
      "User-Agent": [
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0.3 Safari/605.1.15"
      ],
      "Accept-Language": [
        "en-us"
      ],
      "Accept-Encoding": [
        "gzip, deflate, br"
      ]
    },
    "tls": {
      "resumed": false,
      "version": 772,
      "cipher_suite": 4865,
      "proto": "h2",
      "proto_mutual": true,
      "server_name": "tableau.soeller.dev"
    }
  },
  "common_log": "82.102.16.198 - - [11/Feb/2021:16:40:34 +0000] \"GET /tableau HTTP/2.0\" 0 0",
  "duration": 0.00002172,
  "size": 0,
  "status": 0,
  "resp_headers": {
    "Server": [
      "Caddy"
    ]
  }
}

5. What I already tried:

What I tried is putting Tableau on the root route instead behind a path and that does work.
Here is the log to that Tableau on / · GitHub

So I know that in practice it does work.

6. Links to relevant resources:

Configuring Proxies for Tableau Server

[francislavoie]

@5knnbdwm

v2.2.0-rc.1

Please upgrade to v2.3.0!

@5knnbdwm

        route /tableau/* {
                uri * strip_prefix /tableau

You can replace this with just handle_path /tableau/*. The handle_path directive implicitly does strip_prefix for you.

@5knnbdwm

                        header_up X-Forwarded-For {http.request.remote_host}
                        header_up Host {http.request.host}
                        header_up X-Forwarded-Host {http.request.remote_host}
                        header_up X-Forwarded-Proto {http.request.scheme}

Please remove these lines, Caddy does that for you already.

reverse_proxy (Caddyfile directive) - Caddy Documentation

@5knnbdwm

header_up REMOTE_ADDR {http.request.host}

You may also remove this line because that’s not actually a header, but a property of the TCP connection. You don’t need to do anything here. The remote address on requests will always be the IP of the source of the connection.

I think Caddy’s default reverse_proxy behaviour is already appropriate for your needs.

[5knnbdwm]

Ok, thanks for the infos. Yes it is smaller than before. However it still does not work.

tableau.soeller.dev {
        route / {
                respond "Hello, world!"
        }
        handle_path /tableau/* {
                reverse_proxy * http://217.79.180.190:8080
        }
        log {
                output file /root/caddy2.log {
                        roll_local_time true
                }
                format json
        }
}

[francislavoie]

@5knnbdwm

However it still does not work.

Please be specific. What behaviour are you seeing? What’s in your logs? I can’t help with vague statements like that.

Have you upgraded to Caddy v2.3.0?

[5knnbdwm]

Yes have upgraded to v2.3.0.

Yeah sorry. Still get the logs in the beginning. Still just a white screen with a 200 response.

{
  "level": "info",
  "ts": 1613062133.718863,
  "logger": "http.log.access.log0",
  "msg": "handled request",
  "request": {
    "remote_addr": "82.102.16.198:43346",
    "proto": "HTTP/2.0",
    "method": "GET",
    "host": "tableau.soeller.dev",
    "uri": "/tableau",
    "headers": {
      "Accept": [
        "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
      ],
      "User-Agent": [
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0.3 Safari/605.1.15"
      ],
      "Accept-Language": [
        "en-us"
      ],
      "Accept-Encoding": [
        "gzip, deflate, br"
      ],
      "Cookie": [
        "workgroup_session_id=null"
      ]
    },
    "tls": {
      "resumed": false,
      "version": 772,
      "cipher_suite": 4865,
      "proto": "h2",
      "proto_mutual": true,
      "server_name": "tableau.soeller.dev"
    }
  },
  "common_log": "82.102.16.198 - - [11/Feb/2021:16:48:53 +0000] \"GET /tableau HTTP/2.0\" 0 0",
  "duration": 0.000020167,
  "size": 0,
  "status": 0,
  "resp_headers": {
    "Server": [
      "Caddy"
    ]
  }
}

[francislavoie]

@5knnbdwm

Still just a white screen with a 200 response

Oh, that’s because you have your matcher as /tableau/* but you made a request with /tableau. It doesn’t match because you don’t have a trailing / there.

Two ways to fix:

• Easiest way is to change the matcher to /tableau*, but this would mean requests to /tableaufoo would also match (but that might not be a concern)
• Add a rewrite /tableau /tableau/ line just above your handle_path which will ensure the / is there for routing purposes. Adds an extra line to your config but won’t have edgecases.

[5knnbdwm]

Hey, so yeah it did solve a problem. It did load the Tableau signin. Problem now is that Tableau itself redirected me from /tableau to /#/signin which is the other route set-up.

To solve that I again used route /tableau but for that tableau again returned only a white screen.

[francislavoie]

Generally, it’s better to serve apps like this under their own domain. Read this article for more detail:

The "subfolder problem", OR, "why can't I reverse proxy my app into a subfolder?"

Have you ever tried to reverse proxy an app into its own little subfolder of your domain name? Makes things neat, doesn’t it? Using example.com/foo/ for one app, example.com/bar/ for another. If you’re coming here from one of the selfhosted communities, you might be thinking along the lines of example.com/sonarr/, example.com/radarr/ etc. Chances are, you’ve tried some configuration along these lines: example.com { redir /sonarr /sonarr/ handle_path /sonarr/* { reverse_proxy localhost…

Your app may have configuration to allow changing the base path, but if it doesn’t then you’re out of luck and the best thing to do is not serve it under a subpath and give it its own subdomain.

[5knnbdwm]

Okay, thanks for the help. Yeah have it served on a different domain as well, just had to have some access to tableau on the same domain as other things.

But a coworker came up with the solution that we look at which specific paths we need from tableau and make only them redirect to tableau instead of everything.