AKS Gitops (with Flux v2) setup guide

This repo contains instructions on how to setup GitOps with Flux v2 for AKS

Prerequisites

• Azure CLI
• Helm
• kubectl
• flux

Create AKS cluster

1. Create a resource group using the az group create command.

   RG=aks-gitops
   REGION=eastus2
   az login
   az group create --name $RG --location $REGION

2. Create AKS cluster:

   CLUSTER=aks-gitops-cluster
   az aks create --resource-group $RG --name $CLUSTER

3. Log into AKS cluster:

   az aks get-credentials --resource-group $RG --name $CLUSTER --overwrite-existing

Configure Azure Subscription and CLI to use Flux

Register the following Azure resource providers if not already regitered:

az provider register --namespace Microsoft.Kubernetes
az provider register --namespace Microsoft.ContainerService
az provider register --namespace Microsoft.KubernetesConfiguration

Enable CLI extensions:

az extension add -n k8s-configuration
az extension add -n k8s-extension

Install flux extension:

az k8s-extension create -g $RG -c $CLUSTER -n flux-system \
--extension-type microsoft.flux -t managedClusters

Deploy your Gitops (Flux) application

1. Export variablesto use:

   GIT_URL=https://github.com/yortch/aks-gitops
   BRANCH=main

2. Run the following command to initialize the flux system and configuration in the AKS cluster:

   az k8s-configuration flux create --resource-group $RG \
   --cluster-name $CLUSTER --cluster-type managedClusters \
   --name opa-config --scope namespace --namespace opa \
   --kind git --url=$GIT_URL --interval=1m --timeout=2m \
   --branch $BRANCH --kustomization name=opa-kustomize \
   path=./apps/opa/base interval=1m timeout=2m prune=true force=true
   

3. The kustomization above creates a HelmRelease using helm chart from GitRepository (https://github.com/yortch/opa-demo) which creates artifacts in the namespace opa. To validate application, run the following command to get the external IP:

   kubectl get service opa -n opa

4. Copy the EXTERNAL_IP value and navigate to http://{EXTERNAL_IP}:8181 in a browser.

Add additional environment deployments

Use the following command to add a dev flux config:

```bash
az k8s-configuration flux create --resource-group $RG \
--cluster-name $CLUSTER --cluster-type managedClusters \
--name opa-dev-config --scope namespace --namespace opa-dev \
--kind git --url=$GIT_URL --interval=1m --timeout=2m \
--branch $BRANCH --kustomization name=opa-dev-kustomize \
path=./apps/opa/dev interval=1m timeout=2m prune=true force=true retry-interval=1m
```

Add second deployment on the same namespace

This shows how to add a new deployment using a separate helm chart on the same namespace by adding a new kustomization resource:

```bash
az k8s-configuration flux kustomization create --resource-group $RG \
--cluster-name $CLUSTER --cluster-type managedClusters --name opa-config \
--kustomization-name app3-kustomize --path ./apps/app3 \
--prune true --force true --interval 1m --timeout 2m --retry-interval 30s
```