Nginx specifies https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_cache_path: /data/nginx/cache but that doesn't see like a normal place to store anything on ubuntu. Another place suggest /tmp/nginx.
What's an appropriate ubuntu-convention for my cache?
Any place you like; /var/nginx, /var/tmp/nginx, /data/nginx/cache, /home/nginx .. it really doesn't matter, as long as there are enough disk space at the location for the job.
I wouldn't put it in /tmp, since from the olden days, everything there can go away on a reboot.
