Deploy the different GKE cluster

Prerequisite

gcloud installed
terraform installed
kubectl installed

Deploy your cluster

Terraform script help you to deploy and configure your GKE clusters in different region.

First, create a copy of terraform.tfvarstest in terraform.tfvars and replace the values

cp terraform.tfvarstest terraform.tfvars

Then replace set the project id and project number value.

You should have a terraform.tfvars file like :

regions = ["europe-west2","us-central1"]
project_id = "your-project-id"
project_number="your-project-number"

You can change the region ( add, remove or update) values in the regions variable. As an example I propose to go with 2 regions.

Now you can create the clusters by executing these 2 commands.

terraform init
terraform apply
kubectl patch configmap/asm-options -n istio-system --type merge -p '{"data":{"multicluster_mode":"connected"}}'

Now you have different GKE cluster deploy in the regions you choose. ASM is enabled and configured for each cluster.

Configure ASM

export PROJECT_ID="your project ID"
export LOCATION_1=europe-west2
export LOCATION_2=us-central1
export CTX1=gke_${PROJECT_ID}_${LOCATION_1}_${LOCATION_1}-gke
export CTX2=gke_${PROJECT_ID}_${LOCATION_2}_${LOCATION_2}-gke
gcloud container clusters get-credentials ${LOCATION_1}-gke --region ${LOCATION_1}
gcloud container clusters get-credentials ${LOCATION_2}-gke --region ${LOCATION_2}

kubectl create ns demo --context ${CTX1}
kubectl  label namespace demo --context ${CTX1} istio-injection- istio.io/rev=asm-managed --overwrite
kubectl patch configmap/asm-options --context ${CTX1} -n istio-system --type merge -p '{"data":{"multicluster_mode":"connected"}}'

kubectl create ns demo --context ${CTX2}
kubectl  label namespace demo --context ${CTX2} istio-injection- istio.io/rev=asm-managed --overwrite
kubectl patch configmap/asm-options --context ${CTX2} -n istio-system --type merge -p '{"data":{"multicluster_mode":"connected"}}'

Deploy the application

export PROJECT_ID="your project ID"
export LOCATION_1=europe-west2
export LOCATION_2=us-central1
export CTX1=gke_${PROJECT_ID}_${LOCATION_1}_${LOCATION_1}-gke
export CTX2=gke_${PROJECT_ID}_${LOCATION_2}_${LOCATION_2}-gke

kubectl apply -f  application/common --context ${CTX1}
kubectl apply -f  application/common --context ${CTX2}

kubectl apply -f  application/eu --context ${CTX2}
kubectl apply -f  application/us --context ${CTX2}

Test

TOKEN_US=$(curl https://raw.githubusercontent.com/jbleroy1/jwt-token-claim-based-routing/main/jwt/us.jwt -s)
TOKEN_EU=$(curl https://raw.githubusercontent.com/jbleroy1/jwt-token-claim-based-routing/main/jwt/eu.jwt -s)
INGRESS_URL=$(kubectl get mci gke-ingress  -n demo -o jsonpath='{.status.VIP}') 

curl --location --request GET  "http://$INGRESS_URL/" -H "Authorization: Bearer $TOKEN_US"
curl --location --request GET  "http://$INGRESS_URL/" -H "Authorization: Bearer $TOKEN_EU"