Posts Tagged ‘passenger’

passenger standalone with god on rvm

March 21st, 2011 3 comments

Some time ago I have migrated my server to nginx. Now I got first chance to setup rails application on it.

Searching for new experiences I have tried a new setup – passenger standalone on rvm monitored by god and cron (see Q&A on the end).

Prerequisite to that guide is a working deployment script (putting files on server and db:migration working also rvm set up on server). Important is also to replace all occurrences of “/path/to/application” with your real path to application on server.

Nginx is also required, in case you do not have it already you can install it with following command (ubuntu server on linode):

sudo apt-get install nginx

Assuming you have an deploy script up and running you need to add few changes before deployment.

First add god configuration, in your RAILS_ROOT create file config/local.god:

passenger_config = { :instances => (1..3), :path => '/path/to/your/application/current' } do |w| = 'Passenger'
  w.start = "ps -U $USER u | grep -v awk | awk '/nginx/ {print $2}' | xargs kill 2>/dev/null ; passenger start #{passenger_config[:path]} -d -e production -S #{passenger_config[:path]}/tmp/pids/passenger.socket --pid-file #{passenger_config[:path]}/tmp/pids/ --min-instances #{passenger_config[:instances].min} --max-pool-size #{passenger_config[:instances].max}"
  w.stop = "passenger stop #{passenger_config[:path]} --pid-file #{passenger_config[:path]}/tmp/pids/"
  w.pid_file = "#{passenger_config[:path]}/tmp/pids/"
  w.start_if do |start|
    start.condition(:process_running) do |c|
      c.interval = 5.seconds
      c.running = false

Also new gems have to be added in Gemfile:

group :production do 
  gem 'passenger', '~>3.0.5'
  gem 'god', '~>0.11.0'

Now deploy both files to server, they will be needed later on, and do not forget to run

bundle install --without=production

before deployment. Second add an request to restart passenger after deploy:

touch /path/to/application/tmp/restart.txt

If your deployment script is capistrano you should use the following snippet:

namespace :deploy do
  [:start, :stop].each do |method|
    task method, :roles => :app, :except => { :no_release => true } do
      run "local_god #{method} Passenger"
  task :restart, :roles => :app, :except => { :no_release => true } do
    run "touch #{File.join(current_path,'tmp','restart.txt')}"

So now lets go to server to finish configuration.

We need to install god and passenger (which we added on the beginning):

bundle install --without=development test cucumber

please note that cucumber is only required when you use it, skip this param if cucumber is only an tasty vegetable for you.

One of most important steps is to create god wrapper that will be used for starting application (replace my_ruby_1.9.2@my_application with your rvm identifier):

rvm wrapper my_ruby_1.9.2@my_application local god

Next we need to make test run of passenger, it will also compile nginx and notify of any problems if it finds any:

cd /path/to/application/current ; passenger start

Passenger will be started on port 3000 if there is no firewall on server (you missed to install it) then you can visit your browser and enter your server.address:3000. adding -p 8080 would server application on the port 8080 (welcome java users). To stop passenger just hit CTRL+C :)

When that works we can set up proxy in the main nginx configuration. On ubuntu (linode) the steps look as follows:

sudo vim /etc/nginx/available-sites/your-application.conf

and put the following content (do not forget to replace my_domain with your dns name of the server):

server {
  listen 80;
  server_name my_domain;
  access_log /var/log/nginx/my_domain.access.log;
  error_log /var/log/nginx/my_domain.error.log;
  location / {
    proxy_pass http://unix:/path/to/application/current/tmp/pids/passenger.socket;
    proxy_set_header X-Real-IP $remote_addr;

after that (ESC :wq) you need to link configuration and restart server

sudo ln -s /etc/nginx/sites-available/your-application.conf /etc/nginx/sites-enabled/your-application.conf
sudo /etc/init.d/nginx restart

last step is to put local god into autorecovery mode with a simple cron job run crontab -e and enter the following content:

* * * * * ps aux | grep -v grep | grep -q "local\.god" || /home/user_name/.rvm/bin/books_god -c /path/to/application/current/config/local.god

That’s all, in one minute your server should be ready, do not forget that first call to passenger application might be sluggish, but it is only the first one when rails need to be initialized, rest of them is really fast.

To check the whole setup you could put small change in some view, deploy application, refresh your browsers (wait few seconds for rails startup) and check your results.

Q & A

Q: Why passenger, why not unicorn or thin ?

A: It is extremely easy to set up.

A: It is one of the fastest ruby servers (some say it is fastest one).

A: It takes far less memory then glassfish or TorqueBox.

Q: Why passenger standalone, not integrated into apache or nginx?

A: It is integrated with nginx, but installation is automated – almost no manual steps needed.

A: It runs from user context, so it can be fully controled by user and does not affect other users.

A: It does not need to recompile main server – no dependencies for serving other pages, multiple version can be run at the same time.

Q: Why rvm?

A: It allows easy maintenance of ruby version for user installations.

A: It allows to separate gem repositories for multiple applications.

Q: Why God?

A: It allows easy monitoring and management of processes – in our case manage passenger standalone.

Q: Why Capistrano?

A: Really?

Q: Why do you kill nginx when starting passanger?

A: It’s a hack, it might sometimes happen that passenger process is already stopped but nginx did not finished it’s operation yet, so to allow new process to start we kill the old one.

Q: Can I ask a new question, or provide more answers

A: I encourage you to ask questions and give answers, of course I will post only those that give any value.

Missing netbeans passenger support – patch integrated to trunk

March 10th, 2009 Comments off

In one of previous posts (Missing netbeans passenger support – patch ready) I have informed that the patch is ready.

I just got information that the patch was integrated to the netbeans trunk, currently there is no nightly build available but I will post a message when this is ready.

Hope that we can play with passenger in Netbeans shortly.

Categories: Development Tags: , , ,

NICZ SOFT Rails hosting started

February 12th, 2009 Comments off

Additionally to already started blog hosting we have started a new service – Rails hosting.

Basic Configuration is one instance of rails in passenger, one mysql database, and 500MB disk space limit, everything with ssh access.

Anybody interested should leave a note via one of available contact options.

Categories: Hosting, News Tags: , , , ,

Missing netbeans passenger support – patch ready

February 11th, 2009 Comments off

I have just posted a patch that should enable  passanger support in netbeans, details can be viewed at netbeans issues.

Hope that will be shortly merged and everybody can use it.

I do not even know if this is fully functional, I got cold and had few other tasks on head, but this should be good start point.

Most of the logick required to get it running is already writen, so should be enough.

Categories: Development, Linux Tags: , ,

Missing netbeans passenger support

February 8th, 2009 3 comments

Netbeans is missing very important (for me) functionality – support for setting passenger as server. This is even described at netbeans issues:

As I could not find any project that does this job I have already started codding, currently it’s only few lines, but I should get “something” shortly, please let me know if anyone is interested in testing or supporting me in anyway.

Categories: Development Tags: , ,