Traefik won't forward to backend configured with Docker labels - docker

Question

Here's my Traefik configuration:
defaultEntryPoints = ["http", "https"]
[entryPoints]
[entryPoints.http]
address = ":80"
[entryPoints.http.redirect]
entryPoint = "https"
[entryPoints.https]
address = ":443"
[entryPoints.https.tls]
[entryPoints.internal]
address = ":8080"
[entryPoints.traefik]
address = ":8081"
[retry]
[api]
entryPoint = "traefik"
dashboard = true
[file]
[backends]
[backends.traefik]
[backends.traefik.servers.default]
url = "http://127.0.0.1:8081"
[frontends]
[frontends.traefik]
entryPoints = ["internal"]
backend = "traefik"
[frontends.traefik.routes.default]
rule = "Host:localhost;PathPrefixStrip:/traefik;PathPrefix:/traefik"
[docker]
domain = "example.com"
watch = true
exposedbydefault = false
As you can see, I have Traefik dashboard configured to show on localhost:8080/traefik. This works exactly as intended.
I also have very similar configuration for RabbitMQ management UI, set up with docker-compose using labels:
version: '3'
services:
traefik:
image: traefik:alpine
container_name: traefik
ports:
- "80:80"
- "443:443"
- "127.0.0.1:8080:8080"
networks:
- web
- internal
volumes:
- "/var/run/docker.sock:/var/run/docker.sock"
- "./config/traefik/staging.toml:/etc/traefik/traefik.toml"
rabbitmq:
image: rabbitmq:3.7-management-alpine
hostname: rabbitmq
container_name: rabbitmq
networks:
- internal
- default
depends_on:
- traefik
environment:
RABBITMQ_VM_MEMORY_HIGH_WATERMARK: 128MiB
RABBITMQ_ERLANG_COOKIE: temp_cookie_secret
RABBITMQ_NODENAME: rabbit#rabbitmq
volumes:
- "rabbitmqdata:/var/lib/rabbitmq"
labels:
- "traefik.backend=rabbitmq"
- "traefik.docker.network=internal"
- "traefik.frontend.rule=Host:localhost;PathPrefixStrip:/rabbitmq;PathPrefix:/rabbitmq"
- "traefik.enable=true"
- "traefik.port=15672"
- "traefik.protocol=http"
- "traefik.domain=localhost"
networks:
internal:
web:
volumes:
rabbitmqdata
However, this doesn't work: on http://localhost:8080/rabbitmq I get 404 page not found. Traefik dashboard shows that it found my RabbitMQ container and registered rules that are very much like those for Traefik's dashboard:
Where's the mistake here that prevents my setup from working as intended?