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Helm with FluxCD

Updated Aug 19, 2022 ·

Overview​

This is a simple guide on how to use Flux CD to automatically deploy a Helm chart to Kubernetes.

  • Helm charts can be deployed using source code or packaged charts
  • Flux CD detects and deploys the changes from Git automatically

Helm is like a tool that bundles your Kubernetes setup into charts. Flux CD then watches your Git repo to make sure your cluster always matches the setup you saved there.

Helm​

Helm helps you package, deploy, and manage apps in Kubernetes using a structure called charts.

  • Charts group related Kubernetes resources
  • You can version your app deployments with Helm

Charts are like blueprints. With Helm, you install or upgrade apps using those blueprints without writing YAML files from scratch each time.

Helm with Flux CD​

You can store Helm charts and their configs in Git and let Flux CD manage them.

  • Flux can deploy Helm charts from Git or Helm repos
  • You define what you want using YAML files in Git
  • Flux applies the Helm chart to your cluster

Flux CD tracks updates to Helm charts or container images and apply them.

  • It checks for new chart versions in Helm repos
  • It can update charts and values automatically
  • You define rules or policies for updates

For example, if a new chart version comes out, Flux can update your app without you doing anything manually.

HelmRelease Resource​

Flux adds a special object called HelmRelease to manage Helm deployments declaratively.

  • HelmRelease defines the chart, version, and values
  • You commit the HelmRelease file to Git
  • Flux reads it and applies the Helm release

You don’t need to run Helm commands manually. Just update the YAML file in Git, and Flux will do the rest.

Sample HelmRelease:

apiVersion: helm.toolkit.fluxcd.io/v2beta1
kind: HelmRelease
metadata:
  name: my-app
  namespace: default
spec:
  chart:
    spec:
      chart: my-chart
      sourceRef:
        kind: HelmRepository
        name: my-repo
        namespace: flux-system
  interval: 5m
  values:
    replicaCount: 3

This file tells Flux to deploy my-chart from my-repo every 5 minutes with 3 replicas.

Ways to Use Helm Charts​

There are two main ways to use Helm charts with Kubernetes.

  • Use chart source code stored locally
  • Use pre-packaged charts from repositories

Using source code is good for testing while using packaged charts is better for production.