🐳 How to Install WordPress on Docker and Set Up SSL with Let’s Encrypt

Running WordPress inside Docker gives you flexibility, speed, and easy management of your stack. Pair that with free SSL from Let’s Encrypt, and you’ve got a secure, production-ready site running in containers.

In this guide, we’ll walk through how to:

Run WordPress with Docker Compose
Set up a MySQL database container
Reverse proxy using NGINX
Automatically install a free SSL certificate using Let’s Encrypt

Let’s dive in! 🌊

✅ Prerequisites

Before we start, make sure you have:

A domain name pointed to your server (e.g., using A record)
Ubuntu server (or any Linux server)
Docker and Docker Compose installed
Port 80 and 443 open in your firewall

To install Docker and Docker Compose on Ubuntu:

sudo apt update
sudo apt install docker.io docker-compose -y
sudo systemctl enable docker --now

📦 Step 1: Create a Project Directory

mkdir wordpress-docker
cd wordpress-docker

📄 Step 2: Create `docker-compose.yml`

Create a docker-compose.yml file with the following content:

version: '3.8'

services:
  db:
    image: mysql:5.7
    restart: always
    environment:
      MYSQL_DATABASE: wordpress
      MYSQL_USER: wpuser
      MYSQL_PASSWORD: wppassword
      MYSQL_ROOT_PASSWORD: rootpassword
    volumes:
      - db_data:/var/lib/mysql

  wordpress:
    image: wordpress:latest
    restart: always
    depends_on:
      - db
    environment:
      WORDPRESS_DB_HOST: db:3306
      WORDPRESS_DB_NAME: wordpress
      WORDPRESS_DB_USER: wpuser
      WORDPRESS_DB_PASSWORD: wppassword
    volumes:
      - wordpress_data:/var/www/html
    expose:
      - 80

  nginx:
    image: nginx:latest
    restart: always
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx/conf.d:/etc/nginx/conf.d
      - ./nginx/certbot:/etc/letsencrypt
      - ./nginx/www:/var/www/html
    depends_on:
      - wordpress

  certbot:
    image: certbot/certbot
    volumes:
      - ./nginx/certbot:/etc/letsencrypt
      - ./nginx/www:/var/www/html

volumes:
  db_data:
  wordpress_data:

🧾 Step 3: NGINX Config

Create a directory and config file:

mkdir -p nginx/conf.d
nano nginx/conf.d/default.conf

Paste this config (replace yourdomain.com):

server {
    listen 80;
    server_name yourdomain.com www.yourdomain.com;

    location /.well-known/acme-challenge/ {
        root /var/www/html;
    }

    location / {
        return 301 https://$host$request_uri;
    }
}

🚀 Step 4: Start Containers (Initial)

docker-compose up -d

🔐 Step 5: Generate SSL Certificates

Run Certbot manually:

docker-compose run --rm certbot certonly \
  --webroot --webroot-path=/var/www/html \
  --email [email protected] \
  --agree-tos --no-eff-email \
  -d yourdomain.com -d www.yourdomain.com

🌐 Step 6: Update NGINX for HTTPS

Edit nginx/conf.d/default.conf to add SSL:

server {
    listen 80;
    server_name yourdomain.com www.yourdomain.com;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl;
    server_name yourdomain.com www.yourdomain.com;

    ssl_certificate /etc/letsencrypt/live/yourdomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/yourdomain.com/privkey.pem;

    location / {
        proxy_pass http://wordpress:80;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

Restart Docker:

docker-compose down
docker-compose up -d

🔄 Step 7: Automate SSL Renewal (Optional)

Add a cron job to renew every month:

crontab -e

Add this line:

0 0 1 * * docker-compose run --rm certbot renew && docker-compose restart nginx

✅ Final Result

Now your WordPress site should be:

Live at https://yourdomain.com
Secure with HTTPS
Fully containerized using Docker
Easy to maintain and scale

🧠 Final Thoughts

Using Docker + Let’s Encrypt is a powerful combo for hosting WordPress securely and efficiently. Whether you’re a developer or just want better control of your hosting stack, this setup is fast, flexible, and free.

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