Caddy reverse_proxy parsing errors in docker container

[Enzo (Marc)]

1. The problem I’m having:

I’m trying to add additional reverse proxies (actually handle_path but this is a simple example). The following Caddyfile works fine:

localhost:8443 {
	reverse_proxy reveal-vault:8200
	reverse_proxy /whoami whoami:80
}

but once I add another reverse_proxy (see below), caddy complains about an unexpected token r. Now if I run

docker exec -it reveal-caddy caddy fmt --overwrite /etc/caddy/Caddyfile

It returns:

localhost:8443 {
	reverse_proxy reveal-vault:8200
	reverse_proxy /whoami whoami:80
	r

2. Error messages and/or full log output:

Error: adapting config using caddyfile: syntax error: unexpected token 'r', expecting '}', at /etc/caddy/Caddyfile:4 import chain: ['']

3. Caddy version:

v2.7.6 h1:w0NymbG2m9PcvKWsrXO6EEkY9Ru4FJK8uQbYcev1p3A=

4. How I installed and ran Caddy:

a. System environment:

b. Command:

docker exec -it reveal-caddy caddy reload -c /etc/caddy/Caddyfile

c. Service/unit/compose file:

services:
  caddy:
    image: caddy:latest
    container_name: reveal-caddy
    cap_add:
      - NET_ADMIN
    ports:
      - "8443:8443"
      - "8443:8443/udp"
    networks:
      - frontend
      - backend
    volumes:
      - caddy-data:/data/
      - ./caddy/Caddyfile:/etc/caddy/Caddyfile
    restart: always

d. My complete Caddy config:

localhost:8443 {
	reverse_proxy reveal-vault:8200
	reverse_proxy /whoami whoami:80
	reverse_proxy /bob whomami:80
}

5. Links to relevant resources:

[Enzo (Marc)]

Partially answering my own question. It seems the file inside the container is getting mangled.

localhost:8443 {
	reverse_proxy reveal-vault:8200
	reverse_proxy /whoami whoami:80
	r%    

Outside it is correct. If I stop and restart the container, the correct version is seen. I’m running this on MacOS X.

[francislavoie]

What the heck.

Check that the file’s encoding is correct. Use unix line endings, etc.

[Enzo (Marc)]

I’m so use to running docker on Linux I forget that MacOS is not the same. In this case, it seems from the MacOS Host side, the file is a fix byte size. Anything I wrote longer than that got truncated (which explains why I sometimes saw EOF). While changes in the container are mirrored on the Host side.

[francislavoie]

That’s… insane.

I’m sorry you have to use a Mac. Docker on Mac is a disaster.