Traefik on Docker Swarm accessed via Cloudflare Tunnel

.traefik-cloudflare-tunnel

Please see https://mattdyson.org/blog/2024/02/using-traefik-with-cloudflare-tunnels for a detailed write-up of this configuration

environment.env

ROOT_DOMAIN=yourdomain.com
HTTP_TIMEOUT=60
POLLING_INTERVAL=10
PROPAGATION_TIMEOUT=3600
TTL=300
PROVIDERS_GOOGLE_CLIENT_ID=<GOOGLE CLIENT ID>
PROVIDERS_GOOGLE_CLIENT_SECRET=<GOOGLE CLIENT SECRET>
SECRET=RandomTextGoesHere
WHITELIST=<YOUR GOOGLE ACCOUNT EMAIL>
LOG_LEVEL=INFO
ZONE_ID=<YOUR CLOUDFLARE ZONE ID>
TUNNEL_TOKEN=<YOUR CLOUDFLARE TUNNEL TOKEN>

external-app.yaml

version: '3.7'

services:
  whoami:
    image: traefik/whoami
    command:
       - --name=externalapp
    deploy:
      labels:
        - "traefik.enable=true"
        - "traefik.docker.network=traefik"  

        - "traefik.http.routers.external.rule=Host(`external.yourdomain.com`)"
        - "traefik.http.routers.external.entrypoints=websecure"
        - "traefik.http.routers.external.tls=true"
        - "traefik.http.routers.external.middlewares=forward-auth"
        
        - "traefik.http.services.external.loadbalancer.server.port=80"

        - "traefik.constraint=proxy-public"

networks:
  traefik:
    external: true

internal-app.yaml

version: '3.7'

services:
  whoami:
    image: traefik/whoami
    command:
       - --name=internalapp
    deploy:
      labels:
        - "traefik.enable=true"
        - "traefik.docker.network=traefik"  

        - "traefik.http.routers.internal.rule=Host(`internal.yourdomain.com`)"
        - "traefik.http.routers.internal.entrypoints=websecure"
        - "traefik.http.routers.internal.tls=true"

        - "traefik.http.services.internal.loadbalancer.server.port=80"

networks:
  traefik:
    external: true

traefik-docker-compose.yml

version: '3.7'

services:
  reverse-proxy:
    image: traefik:v2.10
    command:
      - "--log"
      - "--log.level=${LOG_LEVEL:-INFO}"
      - "--log.format=json"
      - "--api.insecure=true"
      - "--providers.docker"
      - "--providers.docker.swarmMode=true"
      - "--providers.docker.exposedbydefault=false"
      - "--providers.file.directory=/config"
      - "--providers.file.watch=true"
      - "--serversTransport.insecureSkipVerify=true" # Allow self-signed certificates for target hosts - https://doc.traefik.io/traefik/routing/overview/#insecureskipverify
      - "--metrics"
      - "--metrics.prometheus.buckets=0.1,0.3,1.2,5.0"
      - "--entrypoints.web.address=:80"
      - "--entrypoints.web.http.redirections.entrypoint.to=websecure"
      - "--entrypoints.web.http.redirections.entrypoint.scheme=https"
      - "--entrypoints.websecure.address=:443"
      - "--entrypoints.websecure.http.tls=true"
      - "--entrypoints.websecure.http.tls.certresolver=letsencrypt"
      - "--entrypoints.webinternal.address=:82"
      - "--certificatesresolvers.letsencrypt.acme.email=<YOUR EMAIL>"
      - "--certificatesresolvers.letsencrypt.acme.storage=/etc/traefik/acme/letsencrypt.json"
      - "--certificatesresolvers.letsencrypt.acme.dnschallenge.provider=cloudflare"
      - "--certificatesresolvers.letsencrypt.acme.dnschallenge.delaybeforecheck=300"
      - "--certificatesresolvers.letsencrypt.acme.dnschallenge.resolvers=8.8.8.8:53"
    secrets:
      - cf_token
    environment:
      - CLOUDFLARE_DNS_API_TOKEN_FILE=/run/secrets/cf_token
      - CLOUDFLARE_HTTP_TIMEOUT=${HTTP_TIMEOUT}
      - CLOUDFLARE_POLLING_INTERVAL=${POLLING_INTERVAL}
      - CLOUDFLARE_PROPAGATION_TIMEOUT=${PROPAGATION_TIMEOUT}
      - CLOUDFLARE_TTL=${TTL}
    deploy:
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 3
        window: 120s
      update_config: # Start new instance before stopping existing one
        delay: 10s
        order: start-first
        parallelism: 1
      rollback_config:
        parallelism: 0
        order: stop-first
      placement:
        constraints:
          - node.role == manager
      labels:
        - traefik.enable=true

        - traefik.http.routers.api.rule=Host(`traefik.${ROOT_DOMAIN}`)
        - traefik.http.routers.api.service=api@internal
        - traefik.http.routers.api.entrypoints=websecure
        - traefik.http.routers.api.tls=true

        - traefik.http.services.api.loadbalancer.server.port=8080
    ports:
      # HTTP
      - target: 80
        published: 80

      # HTTPS
      - target: 443
        published: 443
        
      # Web UI (enabled by --api.insecure=true)
      - target: 8080
        published: 8080
    networks:
      - traefik
      - internal
    volumes:
      # So that Traefik can listen to the Docker events
      - /var/run/docker.sock:/var/run/docker.sock
      - acme:/etc/traefik/acme
      - traefik:/config
      - cloudflare:/cloudflare

  traefik-forward-auth:
    image: thomseddon/traefik-forward-auth:2.1.0
    networks:
      - traefik
    environment:
      - PROVIDERS_GOOGLE_CLIENT_ID=${PROVIDERS_GOOGLE_CLIENT_ID}
      - PROVIDERS_GOOGLE_CLIENT_SECRET=${PROVIDERS_GOOGLE_CLIENT_SECRET}
      - SECRET=${SECRET}
      - AUTH_HOST=auth.${ROOT_DOMAIN}
      - COOKIE_DOMAIN=${ROOT_DOMAIN}
      - WHITELIST=${WHITELIST}
    deploy:
      labels:
        - traefik.enable=true
        - traefik.docker.network=traefik

        - traefik.http.routers.auth.rule=Host(`auth.${ROOT_DOMAIN}`)
        - traefik.http.routers.auth.entrypoints=websecure
        - traefik.http.routers.auth.tls=true
        - traefik.http.routers.auth.tls.domains[0].main=${ROOT_DOMAIN}
        - traefik.http.routers.auth.tls.domains[0].sans=*.${ROOT_DOMAIN}
        - traefik.http.routers.auth.tls.certresolver=letsencrypt
        - traefik.http.routers.auth.service=auth@docker

        - traefik.http.services.auth.loadbalancer.server.port=4181

        - traefik.http.middlewares.forward-auth.forwardauth.address=http://traefik-forward-auth:4181
        - traefik.http.middlewares.forward-auth.forwardauth.trustForwardHeader=true
        - traefik.http.middlewares.forward-auth.forwardauth.authResponseHeaders=X-Forwarded-User

        - traefik.http.routers.auth.middlewares=forward-auth

        - traefik.constraint=proxy-public

  tunnel:
    container_name: cloudflared-tunnel
    image: cloudflare/cloudflared
    restart: unless-stopped
    command: tunnel run
    deploy:
      mode: replicated
      replicas: 3
      update_config:
        delay: 30s
        order: start-first
        monitor: 20s
    networks:
      - traefik
    environment:
      - TUNNEL_TOKEN=${TUNNEL_TOKEN}

  error-pages:
    image: tarampampam/error-pages:2.26.0
    environment:
      TEMPLATE_NAME: l7-dark
    networks:
      - traefik
    deploy:
      mode: replicated
      replicas: 2
      update_config:
        delay: 20s
        order: start-first
        monitor: 10s
      labels:
        - traefik.enable=true
        - traefik.docker.network=traefik

        # use as "fallback" for any non-registered services (with priority below normal)
        - traefik.http.routers.error-pages.rule=HostRegexp(`{host:.+}`)
        - traefik.http.routers.error-pages.priority=10

        # should say that all of your services work on https
        - traefik.http.routers.error-pages.tls='true'
        - traefik.http.routers.error-pages.entrypoints=websecure
        - traefik.http.routers.error-pages.middlewares=error-pages
        - traefik.http.services.error-pages.loadbalancer.server.port=8080

        # "errors" middleware settings
        - traefik.http.middlewares.error-pages.errors.status=400-599
        - traefik.http.middlewares.error-pages.errors.service=error-pages
        - traefik.http.middlewares.error-pages.errors.query=/{status}.html

  cloudflare-companion:
    image: ghcr.io/tiredofit/docker-traefik-cloudflare-companion:latest
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    deploy:
      placement:
        constraints:
          - node.role == manager
    environment:
      - TIMEZONE=Europe/London

      - LOG_TYPE=CONSOLE
      - LOG_LEVEL=INFO

      - TRAEFIK_VERSION=2
      - RC_TYPE=CNAME

      - TARGET_DOMAIN=${ROOT_DOMAIN}
      - REFRESH_ENTRIES=TRUE

      - DOCKER_SWARM_MODE=TRUE

      - ENABLE_TRAEFIK_POLL=TRUE
      - TRAEFIK_POLL_URL=https://traefik.${ROOT_DOMAIN}/api
      - TRAEFIK_FILTER_LABEL=traefik.constraint
      - TRAEFIK_FILTER=proxy-public

      - DOMAIN1=${ROOT_DOMAIN}
      - DOMAIN1_ZONE_ID=${ZONE_ID}
      - DOMAIN1_PROXIED=TRUE
    restart: always
    networks:
      - internal
    secrets:
      - cf_token
      
networks:
  traefik:
    external: true
  internal:

volumes:
  acme:
  traefik:
  cloudflare:

secrets:
  cf_token:
    external: true

@mattdy okay I see it authenticated now but seeing below error:

Max retries exceeded with url: /api/api/http/routers (Caused by SSLError(SSLError(1, '[SSL: TLSV1_UNRECOGNIZED_NAME] tlsv1 unrecognized name (_ssl.c:1000)')))

Maybe try without /api at the end of TRAEFIK_POLL_URL? Other than that, I'm afraid I don't know!