GitLab Runner External Scaler for KEDA

This project provides a KEDA External Scaler to dynamically scale GitLab Runners running on Kubernetes based on the number of pending jobs in GitLab.

Features

• Monitors pending jobs via the GitLab API.
• Scales runners based on a configurable pending jobs per runner ratio.
• Supports multiple GitLab instances through the GITLAB_URL environment variable.
• Deployable via Helm.
• Designed for distroless non-root containers.
• Fully compatible with KEDA’s external scaler interface.

Configuration

Env Var	Description
GITLAB_URL	Base URL for the GitLab instance (defaults to https://gitlab.com if not set)
GITLAB_TOKEN	GitLab Personal Access Token (read_api scope)
GITLAB_RUNNER_TAG	Target GitLab Runner tag to filter runners
PENDING_JOBS_PER_RUNNER	Number of pending jobs each runner can handle

Quick Start

1. Build & Push Image:

   docker build -t your-registry/gitlab-runner-scaler:latest .
   docker push your-registry/gitlab-runner-scaler:latest

2. Install Helm Chart:

   helm install gitlab-runner-scaler ./helm-chart \
       --set image.repository=your-registry/gitlab-runner-scaler \
       --set gitlab.token=$(echo -n "your-token" | base64) \
       --set gitlab.runnerTag="java-runner" \
       --set gitlab.pendingJobsPerRunner=10 \
       --set gitlab.gitlabURL="https://gitlab.com"

3. Monitor Scaling:

   kubectl get pods
   kubectl describe scaledobject gitlab-runner-scaler