mediawiki

Demonstation of creation of Chef cookbooks for a LAMP Stack deployment in ami

This cookbook uses Amazon AWS EC2 linux images with Chef 0.10.0 to create four total CentOS systems running in Amazon EC2.

1 haproxy software  load balancer.
2  Media wiki  servers  (  Apache2 web servers running mod_php)
1 MySQL 5.0   database  server.

The PHP mediaapp used in this guide is MediaWiki 1.18alpha

The mediaapp cookbook will perform the following steps:

1. Install required packages and pears for the project
2. set up the deployment scaffolding
3. creates LocalSettings.php file with the dbserver connection information if required
4. performs a revision-based deploy
5. install Apache2 and mod_php
6. create an mediaapp specific virtual host configuration file.

Environment Setup

Have your config file setup corectly
Knife configuration file (knife.rb) validation certificate (thoughtworks-int-validator.pem) user certificate (pratikdam.pem) to ~/chef-repo/.chef/.

Do the following steps to get the config files in the right directory

mkdir ~/mediawiki/.chef
cp ~/chef-repo/.chef/knife.rb ~/mediawiki/.chef
cp ~/chef-repo/.chef/USERNAME.pem ~/mediawiki/.chef
cp ~/chef-repo/.chef/ORGNAME-validator.pem ~/mediawiki/.chef

Add the Amazon AWS credentials to the Knife configuration file.

Ensure that amazon-ec2 can comunicate with knife by the settings in the ~/mediawiki/.chef/knife.rb

knife[:aws_access_key_id] = "praikdam" knife[:aws_secret_access_key] = ""

In addition to the credentials, two additional things need to be configured in the AWS account.Configure the default security group to allow incoming connections for the following ports.

22 - ssh
80 - haproxy load balancer
22002 - haproxy administrative interface
8080 - apache2 web servers running mod_php

Develop Cookbooks

The mediawiki also creates cookbooks for the sake of modularity .Details of the functions of various cookbooks are there in the cookbook README

yum
git
mysql
apache2
haproxy
mediawiki

Upload all the cookbooks to the Hosted Chef server using the command knife cookbook upload -a

Server Roles

All the required roles have been created in the mediawiki repository. They are in the roles/ directory.

base.rb
mediawiki_dbserver_master.rb
mediawiki.rb
mediawiki_load_balancer.rb

Upload all the roles to the Hosted Chef server. rake roles

Data Bag Item

The mediawiki repository contains a data bag item that has all the information required to deploy and configure the MediaWiki mediaapp from source using the recipes in the mediaapp and dbserver cookbooks. The data bag name is apps and the item name is mediawiki. Upload this to the Hosted Chef server.

knife data bag create apps
knife data bag from file apps mediawiki.json

Launch Application

First, launch the dbserver instance.

1. knife ec2 server create -G default -I ami-e565ba8c  -f m1.micro  -S mediawiki -i ~/.ssh/pratikdam.pem -x centos   -r 'role[base],role[mediawiki_dbserver_master]'

Once the dbserver master is up, launch one node that will create the dbserver schema and set up the dbserver with default data.

2. knife ec2 server create -G default -I  mi-e565ba8c   -f m1.micro  -S mediawiki -i ~/.ssh/pratikdam.pem -x centos  -r 'role[base],role[mediawiki],recipe[mediawiki::db_bootstrap]' 

Launch the second mediaapp instance w/o the mediawiki::db_bootstrap recipe.

3. knife ec2 server create -G default -I ami-e565ba8c -f m1.micro  -S mediawiki -i ~/.ssh/pratikdam.pem -x centos   -r 'role[base],role[mediawiki]' 

Once the second mediaapp instance is up, launch the load balancer.

4. knife ec2 server create -G default -I ami-e565ba8c -f m1.micro -S mediawiki -i ~/.ssh/pratikdam.pem -x centos  -r 'role[base],role[mediawiki_load_balancer]'

Verification

Once complete, we would have four instances running in EC2 with MySQL, MediaWiki and haproxy up and available to serve traffic. Knife will output the fully qualified domain name of the instance when the commands complete. Navigate to the public fully qualified domain name on port 80.

http://ec2-23-21-19-43.compute-1.amazonaws.com/

The login is admin and the password is mediawiki.

You can access the haproxy admin interface at:

http://ec2-23-21-19-43.compute-1.amazonaws.com:22002/