Jenkins As Code With Packer, Ansible, Terraform, and AWS
What Will We Cover
1) Build an OS image for AWS with a Jenkins ready to use
2) Provision an EC2 instance to host the Jenkins server
See all the code for this article here: https://github.com/thecloudprofessional/devops_cicd
Using Packer with Ansible to build an AMI image
Packer tool is responsible for creating the OS image, while Ansible is responsible for installing everything we need on this image.
The final version of the image has Jenkins (with "GIT", "Pipeline", and "Pipeline: AWS Steps" plugins), Docker, AWS CLI, Terraform, and Java installed for running Jenkins pipelines hosted on GitHub.
The configuration used is very standard. For simplicity, I decided to use Amazon Linux 2 AMI (HVM) as the source for the AMI and the Ansible Local Provisioner. The latter requires installing Ansible through the shell provisioner on the guest/remote machine before running the playbook.
I’m listing here the roles and their responsibilities:
- AWS CLI: download and install
- Docker: install Docker via YUM and add jenkins user to docker group
- Terraform: download and install
- Jenkins: install Jenkins and its dependencies via YUM, apply custom configuration including basic security, install plugins, create AWS credentials, and create a Jenkins job.
Using Terraform to provision a Jenkins server
Now that we have an image (AMI) with a Jenkins ready to use, we just need to spin up an EC2 instance with this image. This instance must of course be deployed in a public subnet. Terraform is used to provision this infrastructure with code.