[caption id=“attachment_780” align=“alignright” width=“150” caption=“nginx”][/caption] So back in January I had a post about HOWTO: log the user’s IP, not the proxy’s, in Lighttpd access log, but today I switched that system to run nginx (actually nginx has been running since early this year, I just got lazy on running Varnish) fronted again by Varnish. I had the same issue, but not much trouble solving it. Since I often refer to my own notes on fak3r, I’m recording it here for myself, and anyone streaming in from Google.
**UPDATE: **I’m reworking my config blending in the security ideas found on camomel.org they’re really thought things through on this, this should make for a very secure environment. I’m always trying new software, and with the webserver I’ve moved from Apache 1.3 to 2.0 to 2.2, and then later I moved everything over to Lighttpd, which I’ve liked, save for some memory issues that popped up. Now, enter a web server named nginx (engine x), written by a Russian hacker.
Anyone building a server with a LAMP stack today has tons of options, mine have evolved to using Varnish -> Lighttpd -> Xcache -> PHP5 -> MySQL. Once I had Lighttpd (aka Lighty) installed and running PHP pages I looked to optimize the configuration and push it as hard as possible for more speed. Of course lately I’ve been getting unexplained slowdowns, with many instances of php5-cgi appearing to be taking up almost all of my available CPU on top.
Thanks to a post from Steve over at debian-administration.org, I finally got around to setting up monit, the little monitoring app we use at work to keep things sane. I was getting around to installing it at home, but it became more urgent when Varnish went down last week; without it running there’s nothing to handle requests on :80, so as a webserver it’s dead. So here’s my monitrc for the webserver Lighttpd fronted by Varnish, acting in the reverse proxy/http accel role.
When you run a webserver behind a reverse proxy or HTTP accelerator like Squid or Varnish, the webserver access logs will display the IP of the proxy (generally 127.0.0.1) instead of the end user’s IP. This not only breaks any kind of tracking or reporting you want to run against your webserver logs, but it also takes away a datapoint I’ve had use for in general server admin tasks. This server runs Varnish in front of Lighttpd, and it reveals the end user’s IP in the header as X-Forwarded-For, so it’s just a matter of making Lighttpd (lighty) use that variable in its access logs instead of the default variable defining the referring IP.