2.3 - Errors on container start: Is this someting to worry about?

Recently got a fresh Traefik v2 configuration up-and-running in Docker and everything is working, however I'm getting some strange error messages in the logs whenever I start the Traefik container:

time="2020-11-03T15:13:13Z" level=error msg="accept tcp [::]:80: use of closed network connection" entryPointName=web
time="2020-11-03T15:13:13Z" level=error msg="Error while starting server: accept tcp [::]:80: use of closed network connection" entryPointName=web
time="2020-11-03T15:13:13Z" level=error msg="accept tcp [::]:443: use of closed network connection" entryPointName=websecure
time="2020-11-03T15:13:13Z" level=error msg="Error while starting server: accept tcp [::]:443: use of closed network connection" entryPointName=websecure
time="2020-11-03T15:13:13Z" level=error msg="accept tcp [::]:8080: use of closed network connection" entryPointName=traefik
time="2020-11-03T15:13:13Z" level=error msg="Error while starting server: accept tcp [::]:8080: use of closed network connection" entryPointName=traefik
time="2020-11-03T15:13:13Z" level=error msg="Error while starting server: http: Server closed" entryPointName=web
time="2020-11-03T15:13:13Z" level=error msg="Error while starting server: http: Server closed" entryPointName=websecure
time="2020-11-03T15:13:13Z" level=error msg="Error while starting server: http: Server closed" entryPointName=traefik
time="2020-11-03T15:13:27Z" level=info msg="Configuration loaded from file: /traefik.toml"

Traefik is forwarding connections properly to all my containers and I can access the dashboard, but I don't like error messages in my logs.

Does anyone know what might be the cause of these errors? Any idea how to resolve?

Configuration files below:

docker-compose.yml

version: '3'

services:
  reverse-proxy:
    container_name: traefik2.3
    image: traefik:v2.3
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - '/var/run/docker.sock:/var/run/docker.sock'
      - "$PWD/traefik.toml:/traefik.toml"
      - "$PWD/acme.json:/acme.json"
      - "$PWD/tls-options.toml:/tls-options.toml"
    labels:
      - "traefik.http.routers.dashboard.rule=Host(`traefik.[DOMAIN]`) && (PathPrefix(`/api`) || PathPrefix(`/dashboard`))"
      - "traefik.http.routers.dashboard.service=api@internal"
      - "traefik.http.routers.dashboard.middlewares=auth"
      - "traefik.http.middlewares.auth.basicauth.users=[CREDENTIALS]/"
    networks:
      - web
    restart: unless-stopped

networks:
  web:
    external: true

traefik.toml

[global]
  checkNewVersion = true

[entryPoints]
  [entryPoints.web]
    address = ":80"

    [entryPoints.web.http]
    [entryPoints.web.http.redirections]
      [entryPoints.web.http.redirections.entryPoint]
        to = "websecure"
        scheme = "https"

  [entryPoints.websecure]
    address = ":443"

      [entryPoints.websecure.http.tls]
        certResolver = "leresolver"
        options = "raydefault@file"


[certificatesResolvers.leresolver.acme]
  email = "[EMAIL]"
  storage = "acme.json"
  [certificatesResolvers.leresolver.acme.tlsChallenge]

[log]

# Enable API and dashboard
[api]
  dashboard = true

# Enable ping
[ping]

# Enable Docker configuration backend
[providers.docker]
  endpoint = "unix:///var/run/docker.sock"
  exposedByDefault = true
  network = "web"
  watch = true

[providers.file]
  filename = "/tls-options.toml"
  watch = "true"

Thank you!

2 Likes

Hey there I am having a similar issue as well so I am highlighting it here in case it may help you and myself find a resolution quicker and as a bump for your thread since its a related issue.

~$ docker service logs -f traefik_traefik | grep -i error
traefik_traefik.1.o7wrc931rv1z@ninjaserver    | time="2020-11-09T05:09:28Z" level=error msg="accept tcp [::]:8080: use of closed network connection" entryPointName=traefik
traefik_traefik.1.o7wrc931rv1z@ninjaserver    | time="2020-11-09T05:09:28Z" level=error msg="close tcp [::]:8080: use of closed network connection" entryPointName=traefik
traefik_traefik.1.o7wrc931rv1z@ninjaserver    | time="2020-11-09T05:09:28Z" level=error msg="accept tcp [::]:80: use of closed network connection" entryPointName=http
traefik_traefik.1.o7wrc931rv1z@ninjaserver    | time="2020-11-09T05:09:28Z" level=error msg="close tcp [::]:80: use of closed network connection" entryPointName=http
traefik_traefik.1.o7wrc931rv1z@ninjaserver    | time="2020-11-09T05:09:28Z" level=error msg="close tcp [::]:443: use of closed network connection" entryPointName=https
traefik_traefik.1.o7wrc931rv1z@ninjaserver    | time="2020-11-09T05:09:28Z" level=error msg="accept tcp [::]:443: use of closed network connection" entryPointName=https

I don't seem to have dashboard access but it seems the issues may be similar. I have shared my original configuration on separate thread for reference if it helps.

Did you ever find out what is causing those errors? I have the same issue, errors but I can reach everything behind Traefik.

time="2021-02-20T08:10:30-06:00" level=error msg="accept tcp [::]:443: use of closed network connection" entryPointName=websecure
time="2021-02-20T08:10:30-06:00" level=error msg="accept tcp [::]:80: use of closed network connection" entryPointName=web
time="2021-02-20T08:10:30-06:00" level=error msg="Error while starting server: http: Server closed" entryPointName=web
time="2021-02-20T08:10:30-06:00" level=error msg="Error while starting server: http: Server closed" entryPointName=web
time="2021-02-20T08:10:30-06:00" level=error msg="Error while starting server: http: Server closed" entryPointName=websecure
time="2021-02-20T08:10:30-06:00" level=error msg="Error while starting server: http: Server closed" entryPointName=websecure
time="2021-02-20T08:10:30-06:00" level=error msg="close tcp [::]:443: use of closed network connection" entryPointName=websecure
time="2021-02-20T08:10:30-06:00" level=error msg="close tcp [::]:80: use of closed network connection" entryPointName=web

Comment for bump :smiley:
Same on my side.

I have solved this issue.
To do that I have done few things (so not sure what was the root cause):

  • changed challenge method from TLS to HTTP,
  • changed configuration source from flags to a yaml file - for ease of change
  • slight change in networking,

As each set up is different I would recommend to just go through below repo and compare general assumptions, as I did,

Traefik Dockerized

Good luck!

Hi,
could you please explain what "slight changes" you've done in networking?
I'm asking because changes TLS to HTTP and flags to yaml doesn't help. Also, I have the same config in terms of networking as you've published on Github but I still have the same errors in the log file.

I think Traefik tries to start on ipv6 interface and it fails of course. Maybe I'm wrong.

1 Like

I'd like to know too - I'm having the same issues all of a sudden and can't see what is causing it.