Traefik: Docker Containers Not Detected — Fix

The Problem

Traefik is running but doesn’t route traffic to your containers. The dashboard shows no routers or services, or routes show as “not found.” Docker containers with Traefik labels are ignored.

Updated March 2026: Verified with latest Docker images and configurations.

The Cause

Traefik discovers containers through the Docker socket. Common reasons for failure:

1. Docker socket not mounted in the Traefik container
2. --providers.docker=true not set in Traefik’s static configuration
3. Containers are on a different Docker network than Traefik
4. Labels have typos or use wrong syntax
5. traefik.enable=false is set (or exposedByDefault=false and traefik.enable=true is missing)

The Fix

Method 1: Mount the Docker Socket

Verify the Docker socket is mounted in your docker-compose.yml:

services:
  traefik:
    image: traefik:v3.6.11
    command:
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=false"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro

Method 2: Fix Network Configuration

Traefik must share a Docker network with the containers it routes to:

services:
  traefik:
    image: traefik:v3.6.11
    networks:
      - proxy

  myapp:
    image: myapp:latest
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.myapp.rule=Host(`app.example.com`)"
      - "traefik.docker.network=proxy"
    networks:
      - proxy

networks:
  proxy:
    external: true

Create the network first: docker network create proxy

If a container is on multiple networks, you must specify which network Traefik should use with the traefik.docker.network label.

Method 3: Enable Container Exposure

If you set --providers.docker.exposedbydefault=false (recommended), each container must explicitly opt in:

labels:
  - "traefik.enable=true"

Without this label, Traefik ignores the container entirely.

Method 4: Verify Label Syntax

Common label mistakes:

# WRONG — missing router name
- "traefik.http.routers.rule=Host(`app.example.com`)"

# CORRECT — includes router name
- "traefik.http.routers.myapp.rule=Host(`app.example.com`)"

# WRONG — backticks missing
- "traefik.http.routers.myapp.rule=Host(app.example.com)"

# CORRECT — backticks around hostname
- "traefik.http.routers.myapp.rule=Host(`app.example.com`)"

Prevention

• Always use --providers.docker.exposedbydefault=false and explicitly enable containers with traefik.enable=true
• Create a dedicated proxy network and add both Traefik and proxied containers to it
• Test label syntax with docker inspect <container> to verify labels are applied correctly
• Check Traefik dashboard (port 8080) to see which routers and services are detected

Related

• How to Self-Host Traefik
• Docker Networking
• Traefik vs Nginx Proxy Manager