How to record reverse proxy upstream server serving request in Nginx log?

Question

We use Nginx as a reverse proxy with this setup:

upstream frontends {
  server 127.0.0.1:8000;
  server 127.0.0.1:8001;
  server 127.0.0.1:8002;
  [...]
}

s         


        

Answer 1

Use $upstream_addr and you will get, for example, 127.0.0.1:8000 or unix:/home/my_user/www/my_site/tmp/.unicorn.sock