Question

I have “rvm use 1.9.3” and “rvmsudo passenger start –socket (sitename).socket” as prerequisites to get Passenger running under Nginx. Everything else works perfectly, but the question is now how to make sure that all these commands, or some equivalent, work out with Nginx, which boots on system startup. I want this all automated.

This is what my added parts to the nginx.conf look like (# are stuff that apparently works with some configuration of Nginx/passenger, I haven’t tried it at all.)

upstream (sitename)_upstream{
  server unix:/(filepath)
}

server {
  listen 80;
  server_name (url);
  root (filepath);
  access_log (logpath);
  error_log (logpath);
 # passenger_enabled on;
 # rails_spawn_method smart;
 # rails_env development;
  location / {
    proxy_pass http://(sitename)_upstream;
    proxy_set_header Host $host;

  } 

}

So what do I do now?

Answer 1

The trick with processes that start with the system is to make sure that the parts you care about start with the same permissions and user/group as they did when you were initially setting them up. Assuming a Linux system, processes that start at boot are run in /etc/init/d/<script> and run by root (by default) at boot time. You can change your script to run using su to launch as a separate user — actually most server processes do something like this anyway so they run in a protected user environment.

Meanwhile RVM is designed to run as a per-user process. I tried a few months back to set up a server with RVM running globally, and I think this was sort of running against the grain of RVM. So in our case, we made sure our web server (Apache in our case, but Nginx has the same option) started so that its child processes — the ones that actually processed the web requests were run as the same user for which RVM was configured. An alternative would be to grant group-writeable privileges to both the Nginx and RVM users, but this is more work.

The other issue with RVM is that its world is created when the shell script runs — usually the ~/.bash_profile script, and thus, any server that needs to have that same environment may want to run in that shell.

This all sound very hard, but in practice for us, at least, creating a user account that was the one that apps ran as, and installing RVM as that user, with a little other setup, made it all “just work”, especially for cases where you’re running rake, bundle, capistrano, and other stuff.

Sorry, this is a little more general than I had hoped, but maybe it’s useful…