A list of tasks to do when preparing to start a DevOps role (Ansible, AWS, docker, Jenkins, Debian, Python)

devops-warmup.md

DevOps warmup

1. Create a cloudformation template that provisions the following AWS resources:

• VPC
• Subnet
• Internet gateway (with route table entry)
• Security Group (to allow your IP in for SSH)
• IAM role that allows full AWS Route53 access

2. Write an Ansible playbook that

• Runs the cloudformation template
• Provisions a Debian Stretch EC2 instance:
  • In to the VPC created by cloudformation
  • Using the official Debian Stretch AMI for your region of choice
  • Has the IAM role created by cloudformation

3. Write another Ansible playbook that sets up the EC2 instance Debian install:

• Adds a new user
• Installs docker and adds the new user to the docker group - Use the tekniqueltd.docker ansible role via ansible galaxy (also available on github)

4. Create a Route53 domain for a domain or subdomain

• If you don't already have a domain, you can either register a new domain or grab a free subdomain (google free subdomains)

5. Write a python script that updates an A record (under your domain) with the current public IP of the EC2 instance (diy dynamic DNS)

• Use the 'boto' library for AWS calls
• Use the 'requests' library with https://ifconfig.co/ (or similar) to get your current public IP
• Put it in a public git repository on github (create yourself an account if you don't have one)

6. Write a Dockerfile to build a docker image that runs the above python script

• Use debian:stretch as the base image
• Dockerfile should be stored/versioned in the same git repository as the python logic

7. Write a docker-compose file:

• Creates a docker bridge network
• Creates a docker storage volume
• Runs jenkins as a docker container
  • With all jenkins data being stored in the storage volume
  • On the bridge network
  • Listening on TCP 80 (or ideally 443 with valid TLS provided by letsencrypt)

8. Create a Jenkins job for the python script docker image

• Clones the python script repo
• Builds a docker image from the Dockerfile and tags it
• Pushes the docker image with the tag to a hub.docker.com docker repository (create one)

9. Create another Jenkins job for the python script docker image

• Pulls the latest python script docker image
• Runs it
• Runs on a cron every minute

10. Get the python script running using AWS Lambda (for a different A record)