traefik + caddy > Gateway Timeout - docker

Question

I try to use caddy server with traefik in a simple container.
Unfortunatly i get a Gateway Timeout error when i visite the domain. I can't understand if the error is due to traefik or my container.
My docker-compose file:
version: '2'
#
# [ server stack ]
#
services:
web:
image: abiosoft/caddy
container_name: caddy
restart: unless-stopped
networks:
- caddy_network
ports:
- 2015:2015
volumes:
# app
- ./localhost:/srv
# configs
- ./config/Caddyfile:/etc/Caddyfile
labels:
- "traefik.frontend.rule=Host:domain.com"
- "traefik.port=2015"
- "traefik.backend=domain.com"
- "traefik.frontend.entryPoints=http,https"
- "traefik.enable=true"
#
# [ networks definition ]
#
networks:
caddy_network:
driver: bridge
My caddy file:
0.0.0.0:2015
browse
gzip
log stdout
errors stderr
For information, the let's encrypt certificat is perfectly generate by traefik.
Any idea? Could it be a problem with the port config?
[edit]
The traefik config:
################################################################
# Global configuration
################################################################
defaultEntryPoints = ["http", "https"]
logLevel = "DEBUG"
[entryPoints]
[entryPoints.http]
address = ":80"
[entryPoints.http.redirect]
entryPoint = "https"
[entryPoints.https]
address = ":443"
[entryPoints.https.tls]
[acme]
email = "admin#domain.com"
storageFile = "/etc/traefik/acme/acme.json"
entryPoint = "https"
OnHostRule = true
onDemand = true
[[acme.domains]]
main = "domain.com"
sans = ["docker.domain.com", "traefik.domain.com"]
################################################################
# Web configuration backend
################################################################
[web]
address = ":8080"
# MD5
[web.auth.basic]
users = ["admin:xxx"]
################################################################
# Docker configuration backend
################################################################
[docker]
endpoint = "unix:///var/run/docker.sock"
domain = "traefik.domain.com"
watch = true
# Tous les conteneurs seront utilisables par Traefik
# Pour qu'il ne le soit pas, il est nécessaire d'ajouter le label "traefik.enable=false"
# lors de la création du conteneur
exposedbydefault = false
Thank you in advance for the help.
jB

Answer 1

Working solution:
version: '2'
#
# [ server stack ]
#
services:
web:
image: abiosoft/caddy
container_name: caddy
restart: unless-stopped
networks:
- traefik_network
ports:
- 2015:2015
volumes:
# app
- ./localhost:/srv
# configs
- ./config/Caddyfile:/etc/Caddyfile
labels:
- "traefik.frontend.rule=Host:domain.com"
- "traefik.port=2015"
- "traefik.backend=domain.com"
- "traefik.frontend.entryPoints=http,https"
- "traefik.enable=true"
- "traefik.docker.network=traefik_network"
#
# [ networks definition ]
#
networks:
traefik_network:
external: true

Answer 2

It is not necessary to open the port in that container, I meant this line, it is unnecessary and not recomended:
ports:
- 2015:2015