Erisa's Cloudflared Docker Image

This repository contains a simple Dockerfile to build cloudflared, the client for Cloudflare Tunnel, from source.

The aim is to support multiple architectures.
The public image currently supports:

The public image corresponding to this Dockerfile is erisamoe/cloudflared and should work in mostly the same way as the official image.

Cloudflare Tunnel

Dashboard setup (Recommended)

A docker-compose example with a Zero Trust dashboard setup would be:

services:
  cloudflared:
    image: erisamoe/cloudflared
    restart: unless-stopped
    command: tunnel run
    environment:
      - TUNNEL_TOKEN=${TUNNEL_TOKEN}
    depends_on:
      - mycontainer

Where an .env file in the same directory contains TUNNEL_TOKEN= set to the token given by the Zero Trust dashboard. For more information see the Cloudflare Blog

Note A previous version of this README recommended using --token ${CLOUDFLARED_TOKEN}, which is a less secure way of handing off the token. Setting the TUNNEL_TOKEN variable seems to be a better way of approaching this.

Config file setup (Named tunnel)

An example for a setup with a local config would be:

services:
  cloudflared:
    image: erisamoe/cloudflared
    restart: unless-stopped
    volumes:
      - ./cloudflared:/etc/cloudflared
    command: tunnel run mytunnel
    depends_on:
      - mycontainer

Where ./cloudflared is a folder containing the .json or .pem credentials and config.yml for a tunnel.

An example config.yml might look like:

tunnel: uuid-for-tunnel
#Optional
#credentials-file: /etc/cloudflared/uuid-for-tunnel.json

ingress:
  - hostname: mywebsite.com
    service: http://nginx:80
  - service: http_status:404

For more information, refer to the Cloudflare Documentation

To acquire a certificate, you'll need to use the login command.
This will spit out /.cloudflared/cert.pem, rather than /etc/cloudflared.

As such, usage would be something like:

docker run -v $PWD/cloudflared:/.cloudflared erisamoe/cloudflared login

to create a folder called cloudflared in your current dir and deposit a cert.pem into it.

To create a tunnel, you can then do:

docker run -v $PWD/cloudflared:/etc/cloudflared erisamoe/cloudflared tunnel create mytunnel

Which gives you a UUID for the new tunnel and and a .json credentials file corresponding to it.

And now you can either use the above compose example or for testing simply just:

docker run -v $PWD/cloudflared:/etc/cloudflared erisamoe/cloudflared --hostname test.example.com --name mytunnel --hello-world

Which will start up a "Hello world" test tunnel on https://test.example.com.

DNS-over-HTTPS

While not the original intent behind the image, you can also use this to host a DNS resolver that speaks to a DNS-over-HTTPS backend.
For example:

docker run -d -p 53:53/udp --name my-dns-forwarder erisamoe/cloudflared proxy-dns

Would create a container called my-dns-forwarder that responds to DNS requests on your host.
Keep in mind when using this on a public server (e.g. VPS) it will by default listen on all interfaces, making you a public DNS resolver on the internet.
You can sidestep this by changing the -p to instead be -p 127.0.0.01:53:53/udp to listen on localhost instead.

You can also add upstreams with --upstream https://dns.example.com for example. By default, Cloudflare DNS is used.