Connect Your Docker Apps to a Domain

Introduction

This has been something I really struggled when I first try to setup a config for accessing my docker containers using my domain and at the time I couldn't find a proper document that I can understand so I told myself why not write it yourself so here it is.

Update Your System

As a classic, update your system and later install NGINX to your machine.

sudo apt update
sudo apt install nginx

NGINX Setup

After that, go to the following directory and create a config file for your application

cd /etc/nginx/sites-available/
sudo nano /etc/nginx/sites-available/my-app

Later, add the following to your config file with the correct information

server {
    listen 80;
    server_name my-app.your-domain.com;

    location / {
        proxy_pass http://localhost:port-of-your-app;
        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;
    }
}

You can check the ports of your docker applications using docker ps inside your machine.

Then create a symlink from the file you created to the folder where NGINX holds enabled sites.

sudo ln -s /etc/nginx/sites-available/my-app /etc/nginx/sites-enabled/

after that test your config file and restart your nginx instance

sudo nginx -t
sudo systemctl restart nginx

Set DNS Records

For every app you create with the statements below here, you need to set separate DNS records in your domain provider.

Here is how you can do it:

1. Go to your domain provider
2. Open your domain settings and find DNS Records
3. Create a new "A" record with the following configs:
   • Name (Subdomain): the name you used in the creation process. (e.g. my-app)
   • Value: Public IP Address of your server (where you run your application)

You can check if the DNS Records have been changed using this tool. It should show the IP Address of your server when you input your subdomain (my-app.yourdomain.com) if you have done everything correctly.

SSL Certification

sudo apt install certbot python3-certbot-nginx
sudo certbot --nginx -d my-app.your-domain.com

Additional Commands

List the symlinks (enabled NGINX instances) created for your applications:

ls -l /etc/nginx/sites-enabled/

Example output:

/etc/nginx/sites-enabled/my-app -> /etc/nginx/sites-available/my-app

List the available sites for NGINX:

ls /etc/nginx/sites-available/

Side Notes:

1. In case you fuck-up in the process ( like I did :D ) here you can find the default enabled site config file for NGINX. Located under

/etc/nginx/sites-enabled/default

2. You should keep the places where "my-app" is written same, so for example if you are setting up a config for uptime kuma everywhere you should use "kuma" (name depends on you). If you change any of those to a different string it will not work as I experienced.