CodePipeline

A CloudFormation-defined CI/CD pipeline for a Python application, provisioning CodeBuild, CodeDeploy, and CodePipeline, with automated deployment to EC2.

Overview

This project defines a complete CI/CD pipeline as code using AWS CloudFormation templates — rather than manually clicking through the CodePipeline, CodeBuild, and CodeDeploy consoles, each stage of the pipeline is provisioned from a template. The pipeline builds, tests, and deploys a Python application to EC2 using CodeDeploy's lifecycle hook model.

Pipeline Stages

1. Build — buildspec.yml defines the CodeBuild phases, installing dependencies from requirements.txt and running the application build.
2. Test — test_app.py runs automated tests against the application as part of the build process.
3. Deploy — appspec.yml defines the CodeDeploy deployment specification, orchestrating the deployment lifecycle through hook scripts:
   • pre-install-checks.sh — validates the target environment before deployment
   • create-codedeploy-env-vars.sh — sets up environment variables needed for the deployment
   • stop.sh — stops the currently running application
   • run.sh — starts the newly deployed application
   • validate.sh — confirms the deployment succeeded and the application is healthy

Infrastructure as Code

Unlike a pipeline built manually through the AWS console, this repo provisions the pipeline itself from CloudFormation templates:

Template	Provisions
codebuild-template.yml	The CodeBuild project
codedeploy-template.yml	The CodeDeploy application and deployment group
codepipeline-template.yml	The CodePipeline orchestrating source → build → deploy

Repo Contents

File	Purpose
app.py	Python application source
test_app.py	Automated tests
requirements.txt	Python dependencies
buildspec.yml	AWS CodeBuild pipeline definition
appspec.yml	AWS CodeDeploy deployment specification
codebuild-template.yml, codedeploy-template.yml, codepipeline-template.yml	CloudFormation templates provisioning the pipeline infrastructure
pre-install-checks.sh, create-codedeploy-env-vars.sh, run.sh, stop.sh, validate.sh	CodeDeploy lifecycle hook scripts

Tech Stack

Python · AWS CodePipeline · AWS CodeBuild · AWS CodeDeploy · AWS CloudFormation · EC2