How to install Flux System with Git

Introduction

FluxCD is a popular open-source tool for continuous delivery (CD) in Kubernetes environments. In this tutorial, I will show you how to bootstrap a Flux System for your K8s cluster using Git.

Prerequisites

A Git repository.
A running K8s cluster.
Basic knowledge of Kubernetes.
Flux CLI installed on your local machine.

Step-by-step Guide

I use a K8s cluster in my Raspberry Pi and my GitHub repository https://github.com/harrytang/k8 for this demo. I also use the SSH key to authenticate with Github. You can also use any other Git service (GitLab, Bitbucket) if they support SSH Key authentication.

Clone the repository:

git clone [email protected]:harrytang/k8s.git
cd k8s

Generate SSH key for authentication with Github repository:
```
ssh-keygen -t ed25519 -C "raspberrypi"
```
Add the generated public key to the Github repository as Deploy Keys with write access:

Run the Flux bootstrap command:

flux bootstrap git \
  --url=ssh://[email protected]/harrytang/k8s \
  --branch=main \
  --private-key-file=./id_ed25519 \
  --path=clusters/raspberrypi

Delete the generated SSH key:
```
rm id_ed25519
rm id_ed25519.pub
```

Testing

We will try to deploy the cert-manager to test the FluxCD system.

Create the cert-manager namespace at clusters/raspberrypi/cert-manager/namespace.yaml:
```
apiVersion: v1
kind: Namespace
metadata:
  name: cert-manager
```

Create the HelmRepository at clusters/raspberrypi/cert-manager/repository.yaml:

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: HelmRepository
metadata:
  name: jetstack
  namespace: cert-manager
spec:
  interval: 24h
  url: https://charts.jetstack.io

Create the HelmRelease at clusters/raspberrypi/cert-manager/release.yaml:

apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
  name: cert-manager
  namespace: cert-manager
spec:
  interval: 24h
  chart:
    spec:
      chart: cert-manager
      version: '^1.14.4'
      sourceRef:
        kind: HelmRepository
        name: jetstack
        namespace: cert-manager
      interval: 24h
  values:
    crds:
      enabled: true

Create the Kustomization at clusters/raspberrypi/cert-manager/kustomization.yaml:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - namespace.yaml
  - repository.yaml
  - release.yaml

Commit all changes and check the pods deployed by FluxCD:

git add .
git commit -m "feat: adds cert-manager"
git push
kubectl get pods -n cert-manager

NAME                                     READY   STATUS    RESTARTS   AGE
cert-manager-7b9875fbcc-mhd7k            1/1     Running   0          1m
cert-manager-cainjector-948d47c6-f9b5r   1/1     Running   0          1m9s
cert-manager-webhook-78bd84d46b-hxn8v    1/1     Running   0          1m9s

Conclusion

Congratulation! You have successfully bootstrapped the Flux System for your K8s cluster, marking the beginning of your GitOps journey.

References

Flux bootstrap for Git servers.