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Friday, October 22, 2010

Passenger 3, nginx and rvm on Mac OS X 10.6

I wanted to set up the web server nginx, an alternative to Apache, along with Phusion Passenger on my Mac. I've become a convert to RVM as a way to manage multiple versions of Ruby so I needed to setup Passenger (a Ruby gem) through RVM. Whenever you have a combination like that you can run into installation problems.

Here are the steps that I used (after a couple of false starts):

1. Make sure your rvm setup is working correctly. In particular I've found it best to ignore your system Ruby installation completely and in fact I install the system version (currently 1.8.7) separately under rvm and make that my rvm default. You have to reinstall your gems, a pain, but I think it the way to go - everything lives under rvm.

2. Do not install nginx! Passenger will do that for you. If you already have an installation then rename it or just ignore it.

3. Turn off Apache or Nginx if you have either of them running.

4. Put yourself into your default Ruby and install the Passenger gem
$ rvm default
$ gem install passenger

5. Run passenger-install-nginx-module with rvmsudo

Very important - don't use regular sudo - if you do it will complain about not finding the current gemset.
$ rvmsudo passenger-install-nginx-module
The script will ask you if you want a default installation or a custom/advanced on. I just did the default (option 1).

The script downloads and compiles nginx. It will ask you where you want it installed. I suggest /usr/local/nginx. Don't just say /usr/local as that will create conf, html and logs directory right in /usr/local. You really want these in a nginx specific directory.

All being well the compilation and installation will go smoothly and your fresh installation of nginx will be modified for use with passenger.

If I remember the installation correctly it actually fires up nginx and leaves it running. Check that with 'ps ax | grep nginx'

6. Go to your browser.
'http://localhost' should give a 'welcome to nginx' page. Look in /usr/local/nginx/logs/ for logging output.

7. Configuration

I set up a symlink in /usr/local/sbin to the nginx binary so that it can be found in my regular PATH
$ sudo ln -s /usr/local/nginx/sbin/nginx /usr/local/sbin/nginx

You start nginx with 'sudo nginx' and shut it down with 'sudo killall nginx'. It needs to be run via sudo.

Configuring nginx is done in /usr/local/nginx/conf/nginx.conf and if you are used to Apache config files this will be a breath of fresh air. The main changes I made from the default was to set myself as the 'user' and set the worker_processes to 2.

To set up a Rails application simply add a server block like this:
server {
listen 80;
server_name myapp.local;
root /Users/jones/Documents/myapp/public;
passenger_enabled on;
rails_env development;

Be sure to set the rails_env unless you are in production (the default) otherwise it will not work. Restart nginx and with any luck you'll be able to access your application.

I made a few missteps doing my installation - such as thinking I needed to install nginx myself - but overall this went very smoothly.

8. Extra credit

If you want to use rvm and passenger to run multiple apps with multiple versions of Ruby then you will want to look at this post by Phusion:

As you see it can get really complicated, but as a way to migrate a Rails app from 2.x to 3.x and/or Ruby 1.8.x to 1.9.x, this seems like the way to go.



Jason Sydes said...

For multiple versions of ruby, I've just been installing nginx multiple times. When it asks where to install nginx, just choose /opt/nginx-ruby1.9.2 or /opt/nginx-ruby1.8.7 or whatever.

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