Jenkins + Kubernetes + Make + GCC + Google Test + GCOV Demo

This project is a simple C++ HTTP API with one endpoint:

• GET /health -> {"status":"ok"}

It demonstrates:

• Build with make + gcc
• Unit tests with google test
• Coverage with gcov
• Containerization with Docker
• Kubernetes deployment to alpha, beta, prod
• Jenkins pipeline with environment stages

Prerequisites

• g++ / gcc
• make
• gcov
• Google Test headers/libs (gtest)
• Docker Desktop running
• kind
• kubectl

Install Google Test:

# Ubuntu/Debian
sudo apt-get update && sudo apt-get install -y libgtest-dev cmake

# macOS (Homebrew)
brew install googletest

Run API locally

make all
./build/health_api

In another shell:

curl -i http://localhost:8080/health

Unit tests and coverage

make test
./scripts/run_coverage.sh

Coverage gate in scripts/run_coverage.sh requires at least 80% line coverage.

Docker (local app test)

make docker-build
make docker-run
make docker-test
make docker-stop

Local CI/CD stack (kind + local registry + Jenkins)

This project includes scripts and make targets to stand up a complete local pipeline environment.

Start stack:

make local-ci-up

This creates:

• kind cluster: jenkins-kube
• local registry: localhost:5001
• Jenkins container: http://localhost:8081

Get Jenkins admin password:

make local-ci-password

Set up a dedicated Jenkins agent (recommended):

1. In Jenkins UI:
   • Manage Jenkins -> Nodes -> New Node
   • Name: local-agent
   • Type: Permanent Agent
   • Remote root directory: /home/jenkins/agent
   • Labels: local-agent
   • Launch method: Launch agent by connecting it to the controller
   • Save and copy the generated secret from the node page
2. Start agent container from this repo:

   JENKINS_SECRET=<copied-secret> make jenkins-agent-up

3. Pipeline now runs on this agent label (local-agent) instead of the Jenkins controller.

Stop and remove everything:

make local-ci-down

Stop agent only:

make jenkins-agent-down

If make local-ci-up fails with a kind kubelet/control-plane timeout:

1. Ensure Docker Desktop is running and has at least 4 CPUs and 6+ GB memory.
2. Retry with pinned node image (already defaulted in script):

   make local-ci-down
   KIND_NODE_IMAGE=kindest/node:v1.30.8 make local-ci-up

Configure Jenkins job

1. Open Jenkins at http://localhost:8081.
2. Install suggested plugins.
3. Create a Pipeline job.
4. Point it to this repo and use Jenkinsfile.
5. Run with defaults:
   • IMAGE_REPO=localhost:5001/health-api
   • K8S_CONTEXT=kind-jenkins-kube

Pipeline stages run Alpha -> Beta -> Prod. Each stage:

• builds (make all)
• runs tests (make test)
• runs coverage gate (./scripts/run_coverage.sh)
• builds and pushes image to local registry
• deploys Kubernetes manifest and waits for rollout

Kubernetes manifests

Manifests are in k8s/:

• k8s/alpha.yaml -> namespace health-alpha
• k8s/beta.yaml -> namespace health-beta
• k8s/prod.yaml -> namespace health-prod

Image names are injected at deploy time by Jenkins by replacing REPLACE_IMAGE.