GitLab Runner on Kubernetes

This directory contains the configuration and manifests to deploy a GitLab Runner in a Kubernetes cluster using native Kubernetes resources like Deployments, ConfigMaps, Services, and RBAC.

Folder Structure

gitlab-runner/
├── configmap.yaml          # ConfigMap containing the GitLab Runner configuration (config.toml)
├── deployment.yaml         # Deployment manifest for GitLab Runner
├── service.yaml            # Service for exposing Prometheus metrics
├── rbac.yaml               # Role and RoleBinding for GitLab Runner permissions
└── README.md

Documentation for this setup

Prerequisites A Kubernetes cluster with kubectl configured. A valid GitLab instance and registration token. Permissions to create Kubernetes resources in the gitlab-runner namespace. Deployment Steps

1. Create the Namespace

If the gitlab-runner namespace doesn’t exist, create it:

kubectl create namespace gitlab-runner

2. Apply the RBAC Configuration

The rbac.yaml file grants the GitLab Runner the necessary permissions to manage jobs and interact with Kubernetes resources:

kubectl apply -f rbac.yaml -n gitlab-runner

3. Apply the ConfigMap

The configmap.yaml contains the config.toml configuration for the GitLab Runner:

kubectl apply -f configmap.yaml -n gitlab-runner

4. Deploy the GitLab Runner

Apply the deployment.yaml to create the GitLab Runner pod:

kubectl apply -f deployment.yaml -n gitlab-runner

5. Apply the Service

The service.yaml exposes the Prometheus metrics on port 9252 for monitoring:

kubectl apply -f service.yaml -n gitlab-runner

Monitoring the GitLab Runner Check the Pod Status

kubectl get pods -n gitlab-runner

View Logs for Troubleshooting

kubectl logs <pod-name> -n gitlab-runner

Port Forward for Metrics Access

To access Prometheus metrics locally:

kubectl port-forward svc/gitlab-runner-metrics 9252:9252 -n gitlab-runner

Then visit: http://localhost:9252/metrics

Cleanup

To remove all resources related to the GitLab Runner:

kubectl delete -f rbac.yaml -n gitlab-runner
kubectl delete -f configmap.yaml -n gitlab-runner
kubectl delete -f deployment.yaml -n gitlab-runner
kubectl delete -f service.yaml -n gitlab-runner

Future Improvements

Liveness and Readiness Probes: Add health checks in the deployment.yaml to monitor the runner's health. GitOps Integration: Use GitOps tools like ArgoCD or Flux for automated deployments. CI/CD Pipeline: Setup GitLab CI/CD to validate and deploy Kubernetes manifests.

Maintainer: dheva Date: February 2025