Docker, Nginx, and HTTPS Subdomains: A Comprehensive Guide

Certainly! Configuring Docker, Nginx, and HTTPS subdomains involves several steps. Let’s break it down into manageable chunks.
Step 1: Setting up Docker
To start, you’ll need to have Docker installed on your server. If you haven’t already, follow the official Docker installation guide for your operating system. Once you’ve got Docker up and running, you can proceed to the next step.
Step 2: Creating a Nginx Container
Next, you’ll need to create a Docker container running Nginx. Run the following command to pull the official Nginx image from Docker Hub:

docker pull nginx

Once the image is downloaded, you can create a container using the following command:

docker run -d --name my-nginx-container -p 80:80 -p 443:443 nginx

This command will create a new container named my-nginx-container and expose ports 80 and 443.
Step 3: Configuring Nginx
Now that you have a running Nginx container, you need to configure it to handle HTTPS subdomains. First, find the Nginx configuration file located at /etc/nginx/nginx.conf. You can use the following command to open it in your preferred text editor:

docker exec -it my-nginx-container nano /etc/nginx/nginx.conf

In the configuration file, make sure to include the following server block for each subdomain you want to handle:

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

Replace subdomain with your desired subdomain and domain.com with your main domain. This server block listens on port 80 and redirects all HTTP requests to the corresponding HTTPS subdomain.
Step 4: Generating SSL Certificates
Before proceeding to the next step, you’ll need to generate SSL certificates for each subdomain. You can use Let’s Encrypt or any other trusted SSL provider to obtain free SSL certificates. Once you have the certificates, you’ll need to install them in the Nginx container. Use the following command to copy the SSL certificate and key to the Nginx configuration directory:

docker cp path/to/certificate.crt my-nginx-container:/etc/nginx/ssl/
docker cp path/to/private.key my-nginx-container:/etc/nginx/ssl/

Make sure to replace path/to/certificate.crt and path/to/private.key with the actual paths to your SSL certificate and private key files. These files should be in the PEM format.
Step 5: Restarting Nginx
After making the necessary changes to the Nginx configuration file and copying the SSL certificates, you need to restart Nginx for the changes to take effect. Run the following command to restart the container:

docker restart my-nginx-container

Your Nginx container should now be running and handling HTTPS subdomains using SSL certificates. You can test your configuration by visiting each subdomain in a web browser.