Dead simple nginx reverse proxy

reverse_proxy.conf

# Install nginx then stick this in a file in /etc/nginx/sites-enabled

upstream mylighttpdapp {
  # If on the same system:
  # server unix:/some/unix/socket
  # OR
  # server 127.0.0.1:8080 # assuming port 8080 or whatever
  
  # If on a different system just
  # server 1.2.3.4:8080
}

server {
  listen 80;
  listen [::]:80;
  # listen 443 ssl; # If you need https. Fully configuring that left as an exercise, docs online and everything goes in this block
  
  # this is the magic that forwards to the 'upstream' we defined above.
  # obvs you can use proxy_set_header for other headers you need for your app or whatever.
  # The variables in here are defined by nginx for each request, so leave them as-is.
  location / {
    proxy_redirect      off; # this makes the redirect transparent, good for app server isolation and generally recommended
    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-Protocol    $scheme;
    proxy_pass          http://mylighttpdapp; # note that the 'upstream' previously defines this as an http (or https if the upstream has its own SSL certs) endpoint with a sort of fake DNS thing, so this is the desired syntax.
  }

# That's it.  You can have more 'location' blocks if you have, say, static files hosted somewhere other than the app, and
# nginx will always resolve to the most specific / longest path it finds a match for.
}