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.

1. Clone the repository:

   git clone git@github.com:harrytang/k8s.git
   cd k8s
   

2. Generate SSH key for authentication with Github repository:

   ssh-keygen -t ed25519 -C "raspberrypi"
   

3. Add the generated public key to the Github repository as Deploy Keys with write access:

   

4. Run the Flux bootstrap command:

   flux bootstrap git \
     --components source-controller,kustomize-controller,helm-controller,notification-controller \
     --components-extra image-reflector-controller,image-automation-controller \
     --url=ssh://git@github.com/harrytang/k8s \
     --branch=main \
     --private-key-file=./id_ed25519 \
     --path=clusters/raspberrypi
   

   Or, for signing Flux's commits:

   flux bootstrap git \
     --components source-controller,kustomize-controller,helm-controller,notification-controller \
     --components-extra image-reflector-controller,image-automation-controller \
     --url=ssh://git@github.com/harrytang/k8s \
     --branch=main \
     --private-key-file=./id_ed25519 \
     --path=clusters/fusion \
     --gpg-key-id=72B2397E541A5D35 \
     --gpg-key-ring=./keyring.gpg \
     --author-email=it@harrytang.com \
     --author-name=mrgitops    
   

   Run gpg --list-secret-keys --keyid-format=long and look for the key ID, e.g. rsa2048/ABCDEF1234567890 where ABCDEF1234567890 is the key ID.

   Run gpg --export-secret-keys > keyring.gpg to export the GPG keyring.

5. Delete the SSH/GPG key:

   rm id_ed25519
   rm id_ed25519.pub
   rm keyring.gpg
   

Testing

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

1. Create the cert-manager namespace at clusters/raspberrypi/cert-manager/namespace.yaml:

   apiVersion: v1
   kind: Namespace
   metadata:
     name: cert-manager
   

2. 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
   

3. 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
   

4. 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
   

5. 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.