This project builds a simple application architecture with a load balancer which distributes requests between two application servers. The load balancer is running HAProxy, and HAProxy is configured to proxy traffic served from two Apache servers. A deployment playbook is also included, to illustrate zero-downtime deployments with application servers behind HAProxy.
The infrastructure is fairly simple, with the following structure:
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| HAProxy (192.168.56.2) |
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|
_______________________________
| |
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| Apache (192.168.56.3) | | Apache (192.168.56.4) |
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- Download and install VirtualBox.
- Download and install Vagrant.
- [Mac/Linux only] Install Ansible.
- Run
ansible-galaxy install -r requirements.ymlin this directory to get the required Ansible roles. - Run
vagrant upto build the VMs and configure the infrastructure.
When Vagrant is finished provisioning the VMs with Ansible, you should be able to visit http://192.168.56.2/, and you'll see the default Ubuntu Apache 2 'installation complete' page (loaded from one of the two backend web servers through HAProxy).
An example deployment playbook is included at playbooks/deploy.yml. You can run this playbook with the following command:
$ ansible-playbook -i inventory playbooks/deploy.yml
The deployment playbook will run serially over all the webservers, and for each one, take it out of the load balancer, run the deployment (in this case, it just prints a debug message), and put it back in the load balancer once port 80 is available on the webserver.
This project was created by Jeff Geerling as an example for Ansible for DevOps.