Docker compose setup for traefik https using cloudflare DNS resolver

When using cloudflare as my dns, traefik did not work as expected when using it on docker compose. Here is how I solve it.

*In this case, I turn my proxy off. Haven’t tried with proxie on, so feel free to try.

Here’s my docker-compose file for production

version: '3.8'

services:
  api:
    build:
      context: .
    env_file:
      - .env
    expose:
      - 3000
    restart: always
    # volumes:
    #   - ./:/app
    command:
      yarn start
    labels:
      - "traefik.http.routers.api_app.rule=Host(`yourdomain.com`)"
      - "traefik.http.routers.api_app.entrypoints=websecure"
      - "traefik.http.routers.api_app.tls.certresolver=myresolver"
      - "traefik.http.services.api_app.loadbalancer.server.port=3000"
  traefik:
    image: traefik:v2.5
    command:
      - --providers.docker
      - --entrypoints.web.address=:80
      - --entrypoints.websecure.address=:443
      - --certificatesresolvers.myresolver.acme.dnschallenge=true
      - --certificatesresolvers.myresolver.acme.dnschallenge.provider=cloudflare
      - --certificatesresolvers.myresolver.acme.email=YOUR_EMAIL@mail.com
      - --certificatesresolvers.myresolver.acme.storage=/letsencrypt/acme.json
    ports:
      - "80:3000"
      - "443:443"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - ./letsencrypt:/letsencrypt
    environment:
      - CF_API_EMAIL=YOUR_CLOUDFLARE_EMAIL@mail.com
      - CF_API_KEY=YOUR_CLODUFLARE_API_KEY

Explanation

I have two iamge image:

First, my actual application (api) that run on PORT 3000.
Second is traefik setup named “traefik”.

What to watch out:

In labels for the app: make sure change rule Host(…) to your own domain
In labels for the app: make sure server.port pointing to your used PORT
In command of traefik: set dnschallenge.provider to cloudflare
In command of traefik: set resolver email to your email
In environment: change CF_API_EMAIL with your cloudflare email
In environment: change CF_API_KEY to your cloudflare api key (could be global API KEY)

Disclaimer

I’m not a dev ops, so there might be a better solution out there, so far this is what’s working for me.