nginx-letsencrypt

Nginx with auto-renewal Let’s Encrypt script in a single Docker container

Despite the fact that having multiple processes is not true Docker way, sometimes it's very convenient to have just one small container which needs no orchestration infrastructure.

This Dockerfile contains nginx and a simple script which automatically issues an SSL certificate from Let’s Encrypt. It also contains cron task which automatically checks for certificate renewal.

Using in Dockerfile

Dockerfile

FROM megahertz/nginx-letsencrypt:1.0.2

ENV LE_DOMAINS='mydomain.com'

ADD mydomain.conf /etc/nginx/conf.d/mydomain.conf
ADD www /var/www/mydomain.com

mydomain.conf

server {
    listen 443 ssl http2;
    server_name mydomain.com;

    location = / {
       root /var/www/mydomain.com;
       index index.html;
       try_files $uri $uri/ =404;
    }
}

That's it. Just build and run your container:

docker build . -t mydomain.com
docker run -p 80:80 -p 443:443 mydomain.com

Saving certificates

If you would like to prevent loosing certificates when the container removed, set /cert/data path as a volume before first run:

docker run -p 80:80 -p 443:443 -v "./data:/cert/data" mydomain.com

Variables

There are only three environment variables:

LE_DOMAINS

Which domain to use

LE_EMAIL

When issuing a certificate, set email address for Let’s Encrypt.

LE_DEBUG

When testing, it's helpful to set this value to '1'. When enabled, it shows detailed log, executes certificate check each minute and uses Let’s Encrypt staging API. With the staging API you'll receive test certificate instead of real, that prevents you from exceeding issuing limit.