About FluxCD
FluxCD is a continuous delivery (CD) solution for Kubernetes, designed to automate the deployment of applications and infrastructure. It is part of the Cloud Native Computing Foundation (CNCF) and is widely adopted for its GitOps approach, using Git as the single source of truth for declarative infrastructure and application delivery.
Purpose
FluxCD addresses the challenges of managing Kubernetes deployments at scale. Its primary purpose is to:
- Automate deployments: Reduce manual intervention by synchronizing Kubernetes clusters with configurations stored in Git.
- Enforce GitOps principles: Ensure that all changes to infrastructure and applications are version-controlled, auditable, and reproducible.
- Improve reliability: Minimize configuration drift and human errors by using declarative, Git-backed configurations.
- Enable collaboration: Allow teams to collaborate on infrastructure and application changes through pull requests and code reviews.
What does FluxCD do?
FluxCD automates the deployment pipeline for Kubernetes by:
- Pulling changes from Git: FluxCD continuously monitors Git repositories for changes to Kubernetes manifests, Helm charts, or Kustomize configurations.
- Synchronizing clusters: It applies these changes to the target Kubernetes clusters, ensuring the actual state matches the desired state defined in Git.
- Managing dependencies: FluxCD can handle dependencies between resources, such as Helm releases or custom resources.
- Providing observability: It offers detailed logs, metrics, and alerts to track the status of deployments and detect issues early.
Architecture
FluxCD consists of a couple of controllers, where each controller has a certain goal:
| Component | Description |
|---|---|
| Source Controller | Monitors Git repositories for changes to manifests or Helm charts. |
| Kustomize Controller | Applies Kustomize overlays to customize manifests. |
| Helm Controller | Manages Helm releases and charts. |
| Notification Controller | Sends alerts and notifications for deployment events. |
| Image Automation Controller | Automates updates for container images based on policies. |