Setting up Docker container

[rvbcldud]

Hello! This is a really neat project that makes spinning up a reverse proxy super simple. However, I am running into some issues.

I have rust-rpxy running in a docker container (see the snippet of my docker compose file below).

Currently, I have dnsmasq running and resolving domus.files (my file server) to the IP of the rpxy server. The request is received by rpxy and the message in the log indicates it has been forwarded (i.e., it says DEBUG Request to be forwarded: ... with the correct IP and port of my file server). When I type http://domus.files in a browser, it hangs until it usually gets a 502 error code. The log sometimes has this:

ERROR Failed to get response from backend: Failed to fetch from upstream: client error (Connect)...

Do you guys have any input on what I am doing wrong here?

docker compose:

rpxy-rp:
  image: jqtype/rpxy:latest
  container_name: rpxy
  init: true
  restart: unless-stopped
  ports:
    - 80:80
    - 127.0.0.1:8080:8080/tcp
    - 127.0.0.1:8443:8443/udp
    - 127.0.0.1:8443:8443/tcp
  environment:
    - LOG_LEVEL=trace
    - LOG_TO_FILE=true
  tty: false
  privileged: true
  volumes:
    - ./prxy-log:/rpxy/log:rw
    - ./prxy-cache:/rpxy/cache:rw
    - ./prxy-config:/rpxy/config:ro

config file:

listen_port=80

[apps.files]
server_name = "domus.files"
reverse_proxy = [{ upstream = [{ location = '192.168.50.168:5000' }] }]

edit:

I just tried to curl http://domus.files. curl hung for a couple minutes and stopped with no output.

Here is the log:

2025-11-04T17:00:50.594993Z DEBUG Request to be forwarded: [uri http://192.168.50.168:5000/, method: GET, version HTTP/1.1, headers {"host": "do    mus.files", "user-agent": "curl/8.14.1", "accept": "*/*", "x-forwarded-for": "192.168.50.182", "x-forwarded-proto": "http", "x-forwarded-port":     "80", "x-real-ip": "192.168.50.182", "x-forwarded-ssl": "off", "x-original-uri": "/", "proxy": ""}]
2025-11-04T17:03:04.693441Z ERROR Failed to get response from backend: Failed to fetch from upstream: client error (Connect): domus.files <- 192    .168.50.182:63578 -- GET / HTTP/1.1 --  -- / "curl/8.14.1", "192.168.50.182" "http://192.168.50.168:5000/"

[rvbcldud]

It turns out that if I use the "docker address" of the file server, it ends up working. 192.168.50.168 is the address of the machine running the docker containers. The docker address is usually something in 172.18.0.0/24. A good solution may be configuring my docker network to behave very much like my home network (static IPs for each docker containers).

Let me know if anyone that comes across this has more ideas!

[junkurihara]

Hi @rvbcldud

I see that the backend app and rpxy are working on a single machine.

Then, the simple idea is to let both containers join a single virtual bridge network. Then, you don't need to specify the IP address of the app in rpxy's config.toml. You can use the container name + port number, e.g.:

For rpxy:

services:
  rpxy-rp:
    image: jqtype/rpxy:latest
    container_name: rpxy
    ...
    networks:
      net-front:

networks:
  net-front:
    name: net-front

For backend apps:

services:
  files:
    image: files
    container_name: files
    expose:
      - 5000
    ...
    networks:
      net-front:

networks:
  net-front:
    external: true

rpxy.toml

listen_port=80

[apps.files]
server_name = "domus.files"
reverse_proxy = [{ upstream = [{ location = 'files:5000' }] }]

[rvbcldud]

@junkurihara, thanks for the response!

I ended up putting them all on the same virtual bridge network with static IPs, but I really like this method. Using the container name and port is more human-readable and intuitive.

Is using container name + port unique to this project or does this apply to all containers. I am fairly new to docker.

Thanks again!

[junkurihara]

Hi @rvbcldud you're welcome :-)

Resolving with container names is a docker's network feature, so you can use this method to any other docker apps.
https://docs.docker.com/engine/network/#user-defined-networks