Simple nginx lua script to add UUID to each request for end to end request tracking.

nginx.conf

# Dependencies
# nginx_lua
# lua uuid module (luarocks install uuid)

http {

    # this will be the request id
    map $host $request_uuid {
        default '';
    }
    
    log_format  log_with_request_id  '$remote_addr - $remote_user [$time_local] "$request" '
                                     '$status $body_bytes_sent "$http_referer" '
                                     '"$http_user_agent" "$http_x_forwarded_for" '
                                     'request_id: $request_uuid';


    server {
      # your server block here ...
      
      access_log /var/log/nginx.log log_with_request_id;
      
    	set_by_lua $request_uuid '
	      if ngx.var.http_x_request_id == nil then
	        return uuid()
	      else
	        return ngx.var.http_x_request_id
	      end
	    ';
    }

}