Shahzad Bhatti Welcome to my ramblings and rants!

It’s been a few years since I wrote a short HOW-TO on working with EC2 , but recently I tried to migrate the backend of Trading Floor – Facebook and iOS game I have been developing to EC2. So I am documenting the steps for setting up the EC2 for Rails 3.0.

Pre-requisites

I assume you already signed up for EC2, otherwise go to http://aws.amazon.com/ec2/ to signup. Also, you will need Java 5.0 or above, which you can download it from Oracle.

Download EC2 API Tools

First, download EC2 from http://developer.amazonwebservices.com/connect/entry.jspa?externalID=351 and uncompress it in your root directory.

Create a X.509 Certificate

Next, create a X.509 certificate from the AWS Account section. You can then download your certificate and key safely, e.g. I saved them in .ec2 directory under my home directory. Note that you will not be able to download the key again, so don’t lose it.

Environment Variables

Next, I changed my shell as:

 export EC2_HOME=~/ec2-api-tools-1.4.2.4
 export PATH=$PATH:$EC2_HOME/bin
 export EC2_KEY_DIR=~/.ec2
 export EC2_PRIVATE_KEY=$EC2_KEY_DIR/pk-HFG55OCFPZARA6YHW5JGIE6JFD7EQE72.pem
 export EC2_CERT=$EC2_KEY_DIR/cert-HFG55OCFPZARA6YHW5JGIE6JFD7EQE72.pem
 

Where EC2_PRIVATE_KEY and EC2_CERT points to the X.509 key and certificate I downloaded from the Amazon.

Create a Key-Pair

Then I created a pair of keys as:

 ec2-add-keypair plexobject
 

Create a Security Group

I then created a security group for the server

 ec2-add-group web -d 'Web Server'
 ec2-authorize web -P tcp -p 22 -s 0.0.0.0/0
 ec2-authorize web -P tcp -p 80 -s 0.0.0.0/0
 ec2-authorize web -P tcp -p 443 -s 0.0.0.0/0
 

Finding a basic Ubuntu based AMI

Previously I used S3 based AMI, but Amazon now supports EBS based AMIs that has advantage that any changes to the root survive instances of EC2. I launched EC2 instance with basic Ubuntu 11.0 Natty from http://alestic.com/ as:

 ec2-run-instances ami-06ad526f --instance-count 1 --instance-type m1.small \
 --key plexobject --group web -z us-east-1d -m
 

Where -z describes the availability zone and -m turns on monitoring.

Installing Ubuntu Packages

I then proceeded to install basic packages such as Java, Curl, Git, Build, Ruby (1.8.7) and Rails (3.0.3) based on Rails/Ubuntu docs such as:

 sudo apt-get install openjdk-6-jdk
 sudo apt-get install mercurial
 sudo apt-get install curl git-core build-essential zlib1g-dev libssl-dev libreadline5-dev
 sudo  apt-get install libcurl4-openssl-dev 
 sudo apt-get install ruby
 sudo apt-get install rubygems1.8
 sudo gem install rubygems-update
 sudo update_rubygems
 sudo gem install rails
 

I then edited /etc/profile /etc/bash.bashrc and added environment variables

 export PATH=$PATH:/var/lib/gems/1.8/bin/
 export JAVA_HOME=/usr/lib/jvm/java-1.6.0-openjdk/
 

Next, I installed Sqlite and Mysql:

 sudo apt-get install sqlite3 libsqlite3-dev
 sudo gem install sqlite3-ruby
 sudo apt-get install mysql-server mysql-client
 sudo apt-get install libmysql-ruby libmysqlclient-dev
 

Next, I installed Apache and Passenger:

 sudo apt-get install apache2 apache2-mpm-prefork apache2-prefork-dev
 sudo apt-get install apache2-dev libapr1-dev libaprutil1-dev
 sudo gem install passenger
 sudo /var/lib/gems/1.8/gems/passenger-3.0.7/bin/passenger-install-apache2-module*
 

I then edited /etc/apache2/apache2.conf and added:

 LoadModule passenger_module /var/lib/gems/1.8/gems/passenger-3.0.7/ext/apache2/mod_passenger.so
 PassengerRoot /var/lib/gems/1.8/gems/passenger-3.0.7
 PassengerRuby /usr/bin/ruby1.8
 

and then restarted apache

 /etc/init.d/apache2 restart
 

Creating EBS Volume for Data

Next, I created an EBS volume to store all data such as database tables and Rails application from the AWS Console and then attached it to the instance as:

 ec2-stop-instances i-73ab181d 
 ec2-attach-volume  vol-612eaa0a -i i-73ab181d -d /dev/sdf
 ec2-start-instances i-73ab181d 
 

Note that you have to create the EBS volumen in the same availability zone as your instance. I then logged into my machine using

 ssh -i plexobject.pem ubuntu@ec2-50-19-134-251.compute-1.amazonaws.com
 

and then formatted the newly built EBS volume as:

 sudo fdisk -l
 sudo mkfs -t ext4 /dev/xvdf
 

I then edited /etc/fstab and added

 /dev/xvdf       /data   auto    defaults,nobootwait,noatime     0       0
 

and then rebooted machine

 sudo reboot
 

Moving Mysql Data Directory

Mysql installs data directory on the root volume in /var/lib/mysql directory, which I wanted to move to newly created volume. So I created a directory /data/mysql so I stopped mysql:

 sudo /etc/init.d/mysql stop
 

I then copied mysql data directory such as:

 sudo cp -R -p /var/lib/mysql/mysql /data/mysql
 sudo chown -R mysql:mysql /data/mysql/
 

I didn’t copy entire mysql directory, only mysql subdirectory. Next I edited /etc/mysql/my.cnf and changed datadir to /data/mysql directory and then edited /etc/apparmor.d/usr.sbin.mysqld and changed all /var/lib/mysql to /data/mysql. Finally I restarted AppArmor profiles as:

 sudo /etc/init.d/apparmor reload
 

Then restarted mysql:

 sudo /etc/init.d/mysql restart
 

I changed my root password and created a local mysql user as

 mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('mypass');
 mysql> GRANT ALL PRIVILEGES ON *.* TO 'tfuser'@'localhost' IDENTIFIED BY 'mypass' WITH GRANT OPTION;
 mysql> GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON dbname.* TO 'tfuser'@'localhost' IDENTIFIED BY 'mypass';
 

I copied my app to /data/trading_floor and changed permissions of all files to www-data

 sudo chown -R www-data:www-data /data/trading_floor
 

Then created /etc/apache2/sites-available/tf with

 
         ServerAdmin shahbhat@gmail.com
         ServerName tf.plexobject.com
         DocumentRoot /data/trading_floor/public/
         
                  AllowOverride all
                 Options -MultiViews
                 RailsEnv production
          
 
 

Finally, I restarted apache

 /etc/init.d/apache2 restart
 

Creating Elastic IP address

I wanted a permanent IP address for the server so I created EIP using AWS Console. Then associated my instance with the new IP address:

 ec2-associate-address 50.19.248.7 -i i-73ab181d
 

It rebooted your machine with the new IP address. I then changed DNS zone and pointed tf.plexobject.com to 50.19.248.7 (this may take hours to propagate). Next, I changed my Facebook app’s configuration and iOS app’s configuration to point to tf.plexobject.com.

Creating my EBS Image

Once I was happy with the server configuration, I created EBS image for future use. First, I detached data volume and then created image as follows:

 ec2-stop-instances i-f97ca197
 ec2-detach-volume vol-3f65d954
 ec2-create-image i-f97ca197 -n tf-20110601 -d 'Trading Floor Application Server'
 

I terminated my previous instance as

 ec2-terminate-instances -i  i-f97ca197 
 

and created instance with the new image

 ec2-run-instances ami-80837ae9 --instance-count 1 --instance-type m1.small --key tf --group web -z us-east-1d -m
 

After the launch, you would have to reattach the data volume

 ec2-stop-instances i-73ab181d 
 ec2-attach-volume  vol-612eaa0a -i i-73ab181d -d /dev/sdf
 ec2-start-instances i-73ab181d 
 

Summary

Voila, I had my game application running on the cloud. In order to cut per/hour cost I reserved instances for entire year. I am not quite done with my server and am now working on application specific configuration and adding better monitoring/backup. As, we have learned from recent Amazon Cloud outage that deploying your app on the cloud is only half the work, making it performant, scalable and fault tolerant is other half which is still manual work. Finally, I plan to release the Facebook app for Trading Floor and submit iOS app in a couple of weeks, be sure to try it and send me your suggestions.