Merge pull request #30 from appdevgbb/dcasati-local-dev

add a post on Fleet Manager

docs/_posts/2024-09-06-multi-cluster-layer-4-load-balancing-with-fleet-manager

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+---
+title: Multi-Cluster Layer 4 Load Balancing with Fleet Manager
+description: How to configure a multi-cluster layer 4 load balancer across multiple AKS clusters 
+using Fleet Manager.
+authors: 
+  - diego_casati
+---
+
+# Multi-Cluster Layer 4 Load Balancing with Fleet Manager
+This guide demonstrates how to set up layer 4 load balancing across multiple AKS clusters using 
+Azure Fleet Manager. We’ll create two AKS clusters in different regions (East US and West US), 
+configure Virtual Network (VNet) peering between them, and deploy a demo application using 
+Fleet Manager. The process covers AKS cluster setup, VNet peering, Fleet Manager configuration, 
+and application deployment across regions.
+
+
+### Topology
+
+```
++-----------------------+          +-----------------------+
+|    AKS Cluster (East) |          |    AKS Cluster (West) |
+|  Region: East US      |          |  Region: West US      |
+|                       |          |                       |
+| +-------------------+ |          | +-------------------+ |
+| |   Application     | |          | |   Application     | |
+| +-------------------+ |          | +-------------------+ |
+|                       |          |                       |
++-----------------------+          +-----------------------+
+          |                                      |
+          +--------------------------------------+
+                        VNet Peering
+
+             +-----------------------------------+
+             |    Fleet Manager (Hub Region)     |
+             +-----------------------------------+
+```
+
+- [x] AKS Cluster (East): A Kubernetes cluster deployed in the East US region.
+- [x] AKS Cluster (West): A Kubernetes cluster deployed in the West US region.
+- [x] VNet Peering: Virtual Network peering between the AKS clusters to enable communication.
+- [x] Fleet Manager: Azure Fleet Manager deployed in the hub region, managing the application across both AKS clusters.
+
+### Create two AKS clusters
+
+For this demo, we will create two AKS clusters in two regions: East and West.
+
+#### Create the cluster in East US
+
+```bash
+export LOCATION_EAST=eastus2
+export RESOURCE_GROUP_EAST="rg-aks-$LOCATION_EAST"
+export CLUSTER_NAME_EAST="aks-$LOCATION_EAST"
+export AKS_EAST=${CLUSTER_NAME_EAST}
+
+# Create a resource group for the cluster in East US
+az group create \
+  --name ${RESOURCE_GROUP_EAST} \
+  --location ${LOCATION_EAST}
+
+# Create an AKS cluster
+az aks create \
+  --resource-group ${RESOURCE_GROUP_EAST} \
+  --name ${CLUSTER_NAME_EAST} \
+  --network-plugin azure
+
+# get the cluster credentials (East US)
+az aks get-credentials \
+  --resource-group ${RESOURCE_GROUP_EAST} \
+  --name ${AKS_EAST} \
+  --file east-aks
+```
+After the deployment, we need to save the cluster id. This information will be used later when we join the cluster to Fleet Manager as a member:
+
+```bash
+export AKS_EAST_ID=$(az aks show -n ${CLUSTER_NAME_EAST} -g ${RESOURCE_GROUP_EAST} -o tsv --query id)
+```
+Now repeat the same process for the cluster in West US:
+
+```bash
+export LOCATION_WEST=westus2
+export RESOURCE_GROUP_WEST="rg-aks-$LOCATION_WEST"
+export CLUSTER_NAME_WEST="aks-$LOCATION_WEST"
+export AKS_WEST=${CLUSTER_NAME_WEST}
+
+# Create a resource group for the cluster in West US
+az group create \
+  --name ${RESOURCE_GROUP_WEST} \
+  --location ${LOCATION_WEST}
+
+# Create an AKS cluster with Azure CNI
+az aks create \
+  --resource-group ${RESOURCE_GROUP_WEST} \
+  --name ${CLUSTER_NAME_WEST} \
+  --network-plugin azure
+
+# get the cluster credentials (West US)
+az aks get-credentials \
+  --resource-group ${RESOURCE_GROUP_WEST} \
+  --name ${AKS_WEST} \
+  --file west-aks
+
+# cluster ID
+export AKS_WEST_ID=$(az aks show -n ${CLUSTER_NAME_WEST} -g ${RESOURCE_GROUP_WEST} -o tsv --query id)
+```
+
+#### Create the VNets and peer them
+
+Create the VNet for East US:
+
+```bash
+# Create VNet for East US and peer with West US
+create_vnet_and_subnet "$RESOURCE_GROUP_EAST" "$CIDR_EAST" "aks-vnet-east" "$SUBNET_NAME_EAST" "10.1.0.0/24"
+SUBNET_ID_EAST=$(get_subnet_id "$RESOURCE_GROUP_EAST" "aks-vnet-east" "$SUBNET_NAME_EAST")
+```
+
+Create the VNet for West US:
+
+```bash
+# Create VNet for West US and peer with East US
+create_vnet_and_subnet "$RESOURCE_GROUP_WEST" "$CIDR_WEST" "aks-vnet-west" "$SUBNET_NAME_WEST" "10.2.0.0/24"
+SUBNET_ID_WEST=$(get_subnet_id "$RESOURCE_GROUP_WEST" "aks-vnet-west" "$SUBNET_NAME_WEST")
+```
+
+Peer the VNets between East and West US:
+
+```bash
+# Peer VNets between East and West
+peer_vnets "aks-vnet-east" "aks-vnet-west" "$RESOURCE_GROUP_EAST" "aks-vnet-east" "$VNET_ID_WEST" \
+"$RESOURCE_GROUP_WEST" "aks-vnet-west" "$VNET_ID_EAST"
+```
+
+#### Create a Fleet Manager and add members to it
+
+Add the fleet extension to Azure CLI
+
+```bash
+az extension add --name fleet
+```
+
+Create the Fleet Manager resource
+
+```bash
+# setup varibles for Fleet Manager
+export FLEET_RESOURCE_GROUP_NAME=rg-fleet
+export FLEET=gbb-fleet
+export FLEET_LOCATION=westus
+
+# create the resource group
+az group create \
+  --name ${FLEET_RESOURCE_GROUP_NAME} \
+  --location ${FLEET_LOCATION}
+
+# create fleet resource
+az fleet create \
+  --resource-group ${FLEET_RESOURCE_GROUP_NAME} \
+  --name ${FLEET} \
+  --location ${FLEET_LOCATION} \
+  --enable-hub
+```
+
+Retrieve the Cluster IDs for East and West clusters:
+
+```bash
+# Retrieve Cluster IDs (East and West)
+export AKS_EAST_ID=$(az aks show --resource-group ${RESOURCE_GROUP_EAST} --name ${CLUSTER_NAME_EAST} --query "id" -o tsv)
+export AKS_WEST_ID=$(az aks show --resource-group ${RESOURCE_GROUP_WEST} --name ${CLUSTER_NAME_WEST} --query "id" -o tsv)
+```
+
+Now join both clusters to the Fleet:
+
+```bash
+# join the East US cluster
+az fleet member create \
+  --resource-group ${FLEET_RESOURCE_GROUP_NAME} \
+  --fleet-name ${FLEET} \
+  --name ${AKS_EAST} \
+  --member-cluster-id ${AKS_EAST_ID}
+
+# join the West US cluster
+az fleet member create \
+  --resource-group ${FLEET_RESOURCE_GROUP_NAME} \
+  --fleet-name ${FLEET} \
+  --name ${AKS_WEST} \
+  --member-cluster-id ${AKS_WEST_ID}
+```
+
+#### Deploy the AKS store application
+
+For this next step, we will deploy the AKS Store demo application to both clusters, 
+East and West, using Fleet. Fleet Manager will work as a centralized hub, sending the
+configuration and deployment files to its member clusters.
+
+Deploy the application:
+
+```bash
+# create the namespace for the application
+KUBECONFIG=fleet kubectl create ns aks-store-demo
+
+# deploy the application on both clusters thru Fleet
+KUBECONFIG=fleet kubectl apply -n aks-store-demo -f  https://raw.githubusercontent.com/Azure-Samples/aks-store-demo/main/aks-store-ingress-quickstart.yaml
+KUBECONFIG=fleet kubectl apply -n aks-store-demo -f aks-store-serviceexport.yaml
+```
+
+Create the ClusterResourcePlacement (CRP):
+
+```bash
+cat <<EOF > cluster-resource-placement.yaml
+apiVersion: placement.kubernetes-fleet.io/v1beta1
+kind: ClusterResourcePlacement
+metadata:
+  name: aks-store-demo
+spec:
+  resourceSelectors:
+    - group: ""
+      version: v1
+      kind: Namespace
+      name: aks-store-demo
+  policy:
+    affinity:
+      clusterAffinity:
+        requiredDuringSchedulingIgnoredDuringExecution:
+          clusterSelectorTerms:
+            - labelSelector:
+                matchExpressions:
+                  - key: fleet.azure.com/location
+                    operator: In
+                    values:
+                      - eastus2
+                      - westus2
+EOF
+
+kubectl apply -f cluster-resource-placement.yaml
+```
+
+Create and deploy MultiClusterService (MCS):
+
+```bash
+cat <<EOF > aks-store-mcs.yaml
+apiVersion: networking.fleet.azure.com/v1alpha1
+kind: MultiClusterService
+metadata:
+  name: store-front
+  namespace: aks-store-demo
+spec:
+  serviceImport:
+    name: store-front
+EOF
+
+# Deploy the MultiClusterService resource
+KUBECONFIG=east-aks kubectl apply -f aks-store-mcs.yaml
+```
+#### Remove the setup
+To remove this setup, you can run the following set of commands:
+
+```bash
+# East cluster
+az group delete --name ${RESOURCE_GROUP_EAST} --yes --no-wait
+
+# West cluster
+az group delete --name ${RESOURCE_GROUP_WEST} --yes --no-wait
+
+# Fleet Hub
+az group delete --name ${FLEET_RESOURCE_GROUP_NAME} --yes --no-wait
+```
+
+### Conclusion
+In this guide, we successfully set up a multi-cluster layer 4 load balancer across 
+AKS clusters using Azure Fleet Manager. By configuring AKS clusters in different regions, 
+establishing VNet peering, and utilizing Fleet Manager, we enabled centralized management 
+and deployment of services across clusters. This approach ensures improved availability and 
+scalability for applications deployed across multiple regions.
+
+For the full deployment script used in this tutorial, you can access 
+the App Innovation GBB GitHub repository [link].