A simple Nginx reverse proxy for serving multiple Node.js applications from subfolders

I recently set up a VPS on DigitalOcean to run some different Node.js scripts under the same domain.

Now, you cannot have two different Node.js applications listening on the same port, so you must use a reverse proxy. Nginx is usually used for this purpose.

I set each Node application to run in its own subfolder, so I have to edit the Nginx configuration:

sudo nano /etc/nginx/sites-available/default

which was this:

server {
        listen 80 default_server;
        listen [::]:80 default_server;
        root /var/www/html;
        index index.html index.htm index.nginx-debian.html;
        server_name hellonode;
    location ^~ /assets/ {
            gzip_static on;
            expires 12h;
            add_header Cache-Control public;
    }

    location / {
            proxy_http_version 1.1;
            proxy_cache_bypass $http_upgrade;

            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            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://localhost:3000;
    }

}

This configuration allows one Node.js app, running on port 3000, to be the main app served on /.

I wanted to have an app running under /myservice, so I created a Node app listening on port 3001 and I added this configuration:

location /myservice {
        rewrite ^/myservice/(.*)$ /$1 break;
    proxy_http_version 1.1;
    proxy_cache_bypass $http_upgrade;

    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    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://localhost:3001;

}

I checked the configuration was fine using

sudo nginx -t

and I restarted nginx:

sudo systemctl restart nginx  

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