Nginx and Let’s Encrypt with Docker Compose in less than 3 minutes

Overview

This example automatically obtains and renews Let's Encrypt TLS certificates and set up HTTPS in Nginx for multiple domain names using Docker Compose.

You can set up HTTPS in Nginx with Let's Encrypt TLS certificates for your domain names and get A+ rating at SSL Labs SSL Server Test by changing a few configuration parameters of this example.

Let's Encrypt is a certificate authority that provides free X.509 certificates for TLS encryption.
The certificates are valid for 90 days and can be renewed. Both initial creation and renewal can be automated using Certbot.

When using Kubernetes Let's Encrypt TLS certificates can be easily obtained and installed using Cert Manager.
For simple web sites and applications Kubernetes is too much overhead and Docker Compose is more suitable.
But for Docker Compose there is no such popular and robust tool for TLS certificate management.

The example supports separate TLS certificates for multiple domain names, e.g. example.com, anotherdomain.net etc.
For simplicity this example deals with the following domain names:

• test1.evgeniy-khyst.com
• test2.evgeniy-khyst.com

The idea is simple. There are 3 containers:

• Nginx
• Certbot - for obtaining and renewing certificates
• Cron - for triggering certificates renewal once a day

The sequence of actions:

1. Nginx generates self-signed "dummy" certificates to pass ACME challenge for obtaining Let's Encrypt certificates
2. Certbot waits for Nginx to become ready and obtains certificates
3. Cron triggers Certbot to try to renew certificates and Nginx to reload configuration on a daily basis

Initial setup

Prerequisites

1. Docker and Docker Compose are installed
2. You have a domain name
3. You have a server with a publicly routable IP address
4. You have cloned this repository

   git clone https://github.com/evgeniy-khist/letsencrypt-docker-compose.git
   

Step 0 - Create DNS records

For all domain names create DNS A records to point to a server where Docker containers will be running.
Also, consider creating CNAME records for www subdomains.

DNS records

Step 1 - Edit domain names and emails in the configuration

Specify your domain names and contact emails for these domains in the config.env:

DOMAINS=test1.evgeniy-khyst.com test2.evgeniy-khyst.com
CERTBOT_EMAILS=info@evgeniy-khyst.com info@evgeniy-khyst.com

Step 2 - Create named Docker volumes for dummy and Let's Encrypt TLS certificates

docker volume create --name=nginx_ssl
docker volume create --name=letsencrypt_certs

Step 3 - Build images and start containers

docker-compose up -d --build
docker-compose logs -f

Step 4 - Switch to production Let's Encrypt server after verifying HTTPS works with test certificates

Stop the containers:

docker-compose down

Configure to use production Let's Encrypt server in config.env:

CERTBOT_TEST_CERT=0

Re-create the volume for Let's Encrypt certificates:

docker volume rm letsencrypt_certs
docker volume create --name=letsencrypt_certs

Start the containers:

docker-compose up -d
docker-compose logs -f

Adding a new domain to a running solution

Let's add a third domain test3.evgeniy-khyst.com to the running solution.

Step 0 - Create new DNS records

Create DNS A record and CNAME record for www subdomain.

DNS records

Step 1 - Add domain name and email to the configuration

Add new domain name (test3.evgeniy-khyst.com) and contact email to the config.env:

DOMAINS=test1.evgeniy-khyst.com test2.evgeniy-khyst.com test3.evgeniy-khyst.com
CERTBOT_EMAILS=info@evgeniy-khyst.com info@evgeniy-khyst.com info@evgeniy-khyst.com

Step 2 - Create a web root and add static content

Create a web root for a new domain test3.evgeniy-khyst.com:

mkdir html/test3.evgeniy-khyst.com/

Add some static content:

cp html/test1.evgeniy-khyst.com/index.html html/test3.evgeniy-khyst.com/

Step 3 - Restart Docker containers

docker-compose down
docker-compose up -d
docker-compose logs -f

Directory structure

The directories and files:

• docker-compose.yml
• .env - specifies COMPOSE_PROJECT_NAME to make container names independent from the base directory name
• config.env - specifies project configuration, e.g. domain names, emails etc.
• html/
  • test1.evgeniy-khyst.com/ - directory mounted as a web root for Nginx server test1.evgeniy-khyst.com
    • index.html
  • test2.evgeniy-khyst.com/ - directory mounted as a web root for Nginx server test2.evgeniy-khyst.com
    • index.html
• nginx/
  • Dockerfile
  • nginx.sh - entrypoint script
  • hsts.conf - HTTP Strict Transport Security (HSTS) policy
  • default.conf - Nginx configuration with common settings for all domains. The file is copied to /etc/nginx/conf.d/
  • site.conf.tpl - Nginx configuration template. Contains a configuration to get A+ rating at SSL Server Test. Configuration files based on this template are created as /etc/nginx/sites/${domain}.conf. These configuration files are included by default.conf
• certbot/
  • Dockerfile
  • certbot.sh - entrypoint script
• cron/
  • Dockerfile
  • renew_certs.sh - script executed on a daily basis to try to renew certificates

Configuration file structure

To adapt the example to your domain names you need to change only config.env:

DOMAINS=test1.evgeniy-khyst.com test2.evgeniy-khyst.com
CERTBOT_EMAILS=info@evgeniy-khyst.com info@evgeniy-khyst.com
CERTBOT_TEST_CERT=1
CERTBOT_RSA_KEY_SIZE=4096

Configuration parameters:

• DOMAINS - a space separated list of domains to manage certificates for
• CERTBOT_EMAILS - a space separated list of email for corresponding domains. If not specified, certificates will be obtained with --register-unsafely-without-email
• CERTBOT_TEST_CERT - use Let's Encrypt staging server (--test-cert)

Let's Encrypt has rate limits. So, while testing it's better to use staging server by setting CERTBOT_TEST_CERT=1 (default value).
When you are ready to use production Let's Encrypt server, set CERTBOT_TEST_CERT=0.

Thanks to evgeniy-khist!