Dynamically map subdomains to different ports on the server - using Nginx

dynamic_subdomains

server {
    listen 80;

    # maps p8080.example.com -> localhost:8080
    server_name ~^p(?<port>[^.]+)\.example\.com$;

    location / {
        proxy_pass http://localhost:$port;
        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;
    }
}

instructions.md

• You need to create an wilcard A record for the domain(or subdomain) first.

  A * points to 1.2.3.4 Automatic

• Create an nginx config file with above content & restart the web server.

• Done.