Autoscaling Wordpress with Ansible and CloudFormation

http://allandenot.com/devops/2015/12/24/autoscaling-wordpress-with-ansible-and-cloudformation.html

The Goal

• A WordPress site running in EC2 hosts and an RDS database.
• EC2 hosts inside an autoscaling group
• Easily deploy configuration changes

How it works

User runs Ansible playbook:

Notes:

• Baking server exists as a template for the AMI that will be used in CloudFormation.
• Baking server is an Ubuntu with Ansible and local playbooks are copied into it.
• We choose to use baked AMIs to speedup the bootup process when autoscaling is creating new instances. Upon boot, these instances run their local Ansible playbooks and the webserver is configured.

How can I use it

Fork my repository: https://github.com/adenot/blog-ansible-autoscaling-wordpress

Edit file:

group_vars/all

Set variables from your EC2 account.

Make sure to create the required AWS resources for the baking server:

• EC2 Keypair
• VPC, Subnet (if not exists)
• Security group - Port 22/tcp must be open

Running it:

ansible-playbook -vv stack-wordpress.yml

What is happening?

First time it runs:

• a baking server is created
• local playbooks are copied into baking server (from local_wordpress/ansible)
• an AMI is created from the baking server
• a CloudFormation stack is created

Second time it runs:

• local playbooks are copied into baking server (from local_wordpress/ansible)
• an AMI is created from the baking server
• CloudFormation stack is updated with new AMI
• Autoscaling group replaces EC2 instances with new ones using new AMI, one by one