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

• Overview
• Initial setup
  • Prerequisites
  • Step 0 - Create DNS records
  • Step 1 - Edit domain names and emails in the configuration
  • Step 2 - Configure Nginx virtual hosts
    • Serving static content
    • Proxying all requests to a backend server
  • Step 3 - Create named Docker volumes for dummy and Let's Encrypt TLS certificates
  • Step 4 - Build images and start containers using staging Let's Encrypt server
  • Step 5 - verify HTTPS works with the staging certificates
  • Step 6 - Switch to production Let's Encrypt server
  • Step 7 - verify HTTPS works with the production certificates
• Reloading Nginx configuration without downtime
• Adding a new domain to a running solution
  • Step 0 - Create a new DNS records
  • Step 1 - Add domain name and email to the configuration
  • Step 2 - Configure a new Nginx virtual hosts
  • Step 3 - Restart Docker containers
• Directory structure
• Configuration file structure
• SSL configuration for A+ rating

Overview

This example automatically obtains and renews Let's Encrypt TLS certificates and sets 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 an A+ rating in 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 websites 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 daily

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 (or created and cloned a fork):

   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 the www subdomains.

DNS records

Step 1 - Edit domain names and emails in the configuration

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

DOMAINS="test1.evgeniy-khyst.com test2.evgeniy-khyst.com"
CERTBOT_EMAILS="[email protected] [email protected]"

For two and more domains separated by space use double quotes (") around the DOMAINS and CERTBOT_EMAILS variables.

For a single domain double quotes can be omitted:

DOMAINS=test1.evgeniy-khyst.com
[email protected]

Step 2 - Configure Nginx virtual hosts

For each domain configure the Nginx server block by updating vhosts/${domain}.conf:

• vhosts/test1.evgeniy-khyst.com.conf
• vhosts/test2.evgeniy-khyst.com.conf

Serving static content

location / {
    root /var/www/html/my-domain;
    index index.html index.htm;
}

Make sure html/my-domain directory (relative to the repository root) exists and countains the desired content and html directory is mounted as /var/www/html in docker-compose.yml:

services:
  nginx:
  #...
  volumes:
    #...
    - ./html:/var/www/html

Proxying all requests to a backend server

location / {
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_pass http://my-backend:8080/;
}

my-backend is the service name of your backend application in docker-compose.yml:

services:
  my-backend:
    image: example.com/my-backend:1.0.0
    #...
    ports:
      - "8080"

Step 3 - Create named Docker volumes for dummy and Let's Encrypt TLS certificates

docker volume create --name=nginx_conf
docker volume create --name=letsencrypt_certs

Step 4 - Build images and start containers using staging Let's Encrypt server

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

You can alternatively use the docker-compose binary.

For each domain wait for the following log messages:

Switching Nginx to use Let's Encrypt certificate
Reloading Nginx configuration

Step 5 - verify HTTPS works with the staging certificates

For each domain open in browser https://${domain} and https://www.${domain} and verify that staging Let's Encrypt certificates are working:

• https://test1.evgeniy-khyst.com, https://www.test1.evgeniy-khyst.com
• https://test2.evgeniy-khyst.com, https://www.test2.evgeniy-khyst.com

Certificates issued by (STAGING) Let's Encrypt are considered not secure by browsers.

Step 6 - Switch to production Let's Encrypt server

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

Step 7 - verify HTTPS works with the production certificates

For each domain open in browser https://${domain} and https://www.${domain} and verify that production Let's Encrypt certificates are working.

Certificates issued by Let's Encrypt are considered secure by browsers.

Optionally check your domains with SSL Labs SSL Server Test and review the SSL Reports.

Reloading Nginx configuration without downtime

Update a configuration in vhosts/${domain}.conf.

Do a hot reload of the Nginx configuration:

docker compose exec --no-TTY nginx nginx -s reload

Adding a new domain to a running solution

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

Step 0 - Create a 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 a 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="[email protected] [email protected] [email protected]"

Step 2 - Configure a new Nginx virtual hosts

Create a virtual host configuration file vhosts/test3.evgeniy-khyst.com.conf for the new domain.

For example, for serving static content use the following configuration:

location / {
    root /var/www/html/test3.evgeniy-khyst.com;
    index index.html index.htm;
}

Create a webroot html/test3.evgeniy-khyst.com and add static content.

Step 3 - Restart Docker containers

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

Directory structure

• 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.
• nginx/
  • Dockerfile
  • nginx.sh - entrypoint script
  • default.conf - common settings for all domains. The file is copied to /etc/nginx/conf.d/
  • gzip.conf - Gzip compression. Included in default.conf
  • site.conf.tpl - virtual host configuration template used to create configuration files /etc/nginx/sites/${domain}.conf included in default.conf
  • options-ssl-nginx.conf - a configuration to get A+ rating at SSL Server Test. Included in site.conf.tpl
  • hsts.conf - HTTP Strict Transport Security (HSTS) policy. Included in site.conf.tpl
• vhosts/
  • test1.evgeniy-khyst.com.conf - server block configuration for serving static content. Included in site.conf.tpl (include /etc/nginx/vhosts/${domain}.conf;)
  • test2.evgeniy-khyst.com.conf - server block configuration for serving static content. Included in site.conf.tpl (include /etc/nginx/vhosts/${domain}.conf;)
• html/
  • test1.evgeniy-khyst.com/ - directory mounted as a webroot for test1.evgeniy-khyst.com. Configured in vhosts/test1.evgeniy-khyst.com.conf
    • index.html
  • test2.evgeniy-khyst.com/ - directory mounted as a webroot for test2.evgeniy-khyst.com. Configured in vhosts/test2.evgeniy-khyst.com.conf
    • index.html
• 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="[email protected] [email protected]"
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.

SSL configuration for A+ rating

SSL in Nginx is configured accoring to best practices to get A+ rating in SSL Labs SSL Server Test.

Read more about the best practices and rating:

• https://github.com/ssllabs/research/wiki/SSL-and-TLS-Deployment-Best-Practices
• https://github.com/ssllabs/research/wiki/SSL-Server-Rating-Guide