Simple Continues Integration Pipeline with Jenkins and Ansible

The key point of this setup - it is One Click installation,

once you have ansible setup on your laptop it is a matter of one command to install everything. After it complets you just commit your changes and after the tests they appear at the application endpoint.

The goal is to setup Jenkins to poll Github, test the latest commit and deploy the app if everyhing is ok

The application is a simple Python Flask hello world. See the souce code at: demo app

The most challenge part was to setup Jenkins in container and make it fully automatically.

On my laptop:

• Python3 is installed
• Virtual env is created
• Password file with password for Ansible Vault is created.
• Ansible is installed
• Digital Ocean token accuired and put in secrets.yaml
• Docker Hub token is accuired
• New SSH keys generated and added to demo app repo as deployment keys. id_rsa is encrypted by Ansible Vault

Main Playbook that setups everything is here

• create 2 Digital Ocean droplets and register DNS record for one of them at demapp.politerobots.com, it will be an application host
• on Application host it does:
  • let Jenkins to login via ssh
  • let docker pull to work
  • let Ansible to manage docker
  • setup nginx with firewall access

playbook

• on Jenkins host it does:
  • create jenkins user
  • setup Ansible
  • put deployment jenkins job, see it there
  • fix docker push/pull
  • build and run Jenkins container from this Dockerfile

playbook

• the app deployment procedure described here

Kubernetes

Whatever we like or not K8S is the standard environment to run applications these days. I like it because I had a lot of problems with different approaches like Docker Sware, docker-compose etc. Usually, K8S just works for the statless application. I believe databases should be running as dedicated services by cloud providers.

SSL

Jenkins is running on 127.0.0.1 but demo application uses SSL and available at: https://demapp.politerobots.com/