docker-certbot-cron

Create and automatically renew website SSL certificates using the letsencrypt free certificate authority, and its client certbot. Define the environment variables DOMAINS (space-separated list of fully-qualified domain names) and EMAIL (your letsencrypt registration email) to automatically run certbot to renew/fetch your SSL certificates in the background. Configure nginx to pass off the ACME validation challenge, and you'll have zero-downtime, 100% automatic SSL certificates for all your Docker containers!

ACME Validation challenge

To authenticate the certificates, the you need to pass the ACME validation challenge. This requires requests made on port 80 to your.domain.com/.well-known/ to be forwarded to this container.

The recommended way to use this image is to set up your reverse proxy to automatically forward requests for the ACME validation challenges to this container.

Nginx example

If you use nginx as a reverse proxy, you can add the following to your configuration file in order to pass the ACME challenge.

server {
    listen 80;
    location '/.well-known/acme-challenge' {
        default_type "text/plain";
        # Note: this works with docker-compose only if the service name is `certbot`,
        # and the `nginx` service `depends_on` the `certbot` service!
        proxy_pass http://certbot:80;
    }
}

docker-compose example

To use this container with docker-compose, put something like the following into your configuration:

version '2'
services:
...
    certbot:
        image: staticfloat/docker-certbot-cron
        container_name: certbot
        volumes:
            - certbot_etc_letsencrypt:/etc/letsencrypt
        restart: unless-stopped
        environment:
            - DOMAINS="foo.bar.com baz.bar.com"
            - EMAIL=email@domain.com
...
    nginx:
        ...
        depends_on:
            - certbot
        volumes:
            - certbot_etc_letsencrypt:/etc/letsencrypt:ro
...
volumes:
    certbot_etc_letsencrypt:
        external: true

I personally like having my certificates stored in an external volume so that if I ever accidentally run docker-compose down I don't have to re-issue myself the certificates.

More information

Find out more about letsencrypt: https://letsencrypt.org

Certbot github: https://github.com/certbot/certbot

This repository was originally forked from @henridwyer, many thanks to him for the good idea. I've basically taken his approach and made it less flexible/simpler for my own use cases, so if you want this repository to do something a particular way, make sure his repo doesn't already do it.

Changelog

0.5

• Change the name to docker-certbot-cron, update documentation, strip out even more stuff I don't care about.

0.4

• Rip out a bunch of stuff because @staticfloat is a monster, and likes to do things his way

0.3

• Add support for webroot mode.
• Run certbot once with all domains.

0.2

• Upgraded to use certbot client
• Changed image to use alpine linux

0.1

• Initial release