pastbedti.me » Hosting

Deploying a Sinatra app with Apache and Phusion Passenger a.k.a. mod_rack

Mathias Stjernström — Mon, 30 Nov 2009 22:01:30 +0000

My Sinatra + Apache + Passenger setup did not just run

Deploying a simple Sinatra rack application under Apache and Phusion Passenger turned out not work out of the box for me.

I already had a virtual host so I decided to deploy with passengers sub URI (sub URI documentation).

To make this work you’ll need Apache installed with Phusion Passenger setup (Passenger installation)

This is what I started with

This is my folders for the already existing website.

1
2
3
4

# Existing homedir
/home/my_web/
# Current webroot
/home/my_web/htdocs

Creating folders and files for Sinatra

The first thing you want to do is to create folders and files for Sinatra.

1	mkdir /home/my_web/sinatra

1
2
3
4
5
6

cd /home/my_web/sinatra
mkdir tmp
mkdir logs
mkdir public
touch app.rb
touch config.ru

Create symlink

Create a symbolic link from our current webroot to the new Sinatra app so that apache/passenger can find it.

1	ln -s /home/my_web/sinatra/public /home/my_web/htdocs/app

Creating the application

We also need a Sinatra application for this to work so lets fill those files.

File: config.ru

1
2
3
4
5
6
7
8
9
10
11

require 'app'

set :environment, ENV['RACK_ENV'].to_sym
set :app_file, 'app.rb'
disable :run

log = File.new("logs/sinatra.log", "a")
STDOUT.reopen(log)
STDERR.reopen(log)

run Sinatra::Application

File: app.rb

1
2
3
4
5
6
7
8
9
10
11

require 'rubygems'
require 'sinatra'

before do
# Strip the last / from the path
request.env['PATH_INFO'].gsub!(/\/$/, '')
end

get '' do
"Hello world"
end

Apache configuration

Now we need to setup apache so that it can find our Sinatra app and load it.

The only thing you need to do is add the following line to your existing VirtualHost block:

1	RackBaseURI /app

This line will tell passenger to look into our existing webroot for a symlink thats named app and which points to our rack app. (RackBaseURI documentation)

Virtual host entry

1
2
3
4
5
6
7
8
9
10
11
12

<VirtualHost *:80>
ServerName www.example.com
ServerAlias example.com
DocumentRoot /home/my_web/htdocs/
RackBaseURI /app

<Directory "/home/my_web/htdocs/">
Order allow,deny
Allow from all
AllowOverride All
Directory>
VirtualHost>

The best part is that you are allowed to specify this option multiple times. So you can easily setup multiple apps under the same virtual host.

Cheers!

Gentoo/Linux freezing under VMware ESX/ESXi

Mathias Stjernström — Wed, 05 Nov 2008 22:02:58 +0000

We recently got in trouble with two Gentoo machines that where running under VMware ESX & ESXi.

The hosts froze randomly (Even the console in vmware froze). Especially when putting a little load on the machines. After hours of testing we found that removing virtual CPU’s from the host solved the problem. More that one CPU got the machine to freeze after some time.

!! Unsatisfied solution !! So after a couple of more hours we found a working solution….

The solution was to disable the time stamp counter hardware in the host. This is done by passing notsc on the kernel command line.

We found people running Ubuntu with a similar problem and some of them solved the problem with passing clocksource=acpi_pm on the kernel command line. The clocksource problem is known by VMware and more information can be found here http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1007020. This did however not solved our problem but some readers may find it helpful.

Cheers!

Redirecting with nginx

Mathias Stjernström — Wed, 21 May 2008 17:22:37 +0000

Today one of our server got in trouble with an ACE encoded IDN domain. The problem seemed to be rails in combination with nginx’s X-Sendfile feature. The result became that when accessing the site trough the IDN domain x-senfile did not send any files….

Our quick and dirty solution (until we have found the source/or solved the problem) became redirecting all traffic from the IDN domain to the domain without strange-swedish-characters.

With nginx this is as simple as in most webservers just put the following code before you original server configuration in nginx.conf.

1
2
3
4

server {
server_name xn--svenskdomn-y5a.se www.xn--svenskdomn-y5a.se;
rewrite ^(.*) http://www.svenskdoman.se$1 permanent;
}

And Bowang! All requests to www.svenskdomän.se will be redirected to www.svenskdoman.se.

Domain names have been changed to protect the innocent

Cheers!