The traffic in multi-cluster should be consider under the same mesh.
So the virtual Service should use gateway mesh.
Reference document:
- Istio Replicated control planes
- Using Istio to load-balance internal gRPC services
- GoogleCloudPlatform/istio-samples
Create Google Cloud Platform project and enable APIs.
Install gcloud SDK.
Create GKE clusters.
# Cluster - client
gcloud container clusters create cluster-1 \
--machine-type e2-standard-2 \
--zone asia-east1-a \
--enable-ip-alias
# Cluster - server
gcloud container clusters create cluster-2 \
--machine-type e2-standard-2 \
--zone us-west2-a \
--enable-ip-alias
Export environment variables
export GOOGLE_CLOUD_PROJECT=<YOUR_PROJECT_NAME>
export CTX_CLUSTER1="gke_$GOOGLE_CLOUD_PROJECT_asia-east1-a_cluster-1"
export CTX_CLUSTER2="gke_$GOOGLE_CLOUD_PROJECT_us-west2-a_cluster-2"
Download Istio 1.6.8
export ISTIO_VERSION=1.6.8
export ISTIO_PATH=$PWD/istio-$ISTIO_VERSION
curl -L https://istio.io/downloadIstio | sh -
export PATH=$ISTIO_PATH/bin:$PATH
git clone https://github.com/GoogleCloudPlatform/istio-samples.git
cd istio-samples/sample-apps/grpc-greeter-go
gcloud builds submit server -t gcr.io/$GOOGLE_CLOUD_PROJECT/grpc-greeter-go-server
cd -
cd istio-samples/sample-apps/grpc-greeter-go/client
CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o grpc-client -installsuffix "static" .
cd -
Context switch
kubectl config use-context $CTX_CLUSTER2
Install Itsio
cd $ISTIO_PATH
kubectl create namespace istio-system
kubectl create secret generic cacerts -n istio-system \
--from-file=samples/certs/ca-cert.pem \
--from-file=samples/certs/ca-key.pem \
--from-file=samples/certs/root-cert.pem \
--from-file=samples/certs/cert-chain.pem
istioctl install \
-f manifests/examples/multicluster/values-istio-multicluster-gateways.yaml \
--set meshConfig.accessLogFile=/dev/stdout
cd -
Setup Cluster 2
kubectl label namespace default istio-injection=enabled
kubectl apply -f cluster-2
kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
name: greeter
spec:
replicas: 3
selector:
matchLabels:
app: greeter
template:
metadata:
labels:
app: greeter
spec:
containers:
- args:
- --address=127.0.0.1:8080
image: gcr.io/$GOOGLE_CLOUD_PROJECT/grpc-greeter-go-server
imagePullPolicy: Always
livenessProbe:
exec:
command:
- /bin/grpc_health_probe
- -addr=:8080
initialDelaySeconds: 2
name: greeter
ports:
- containerPort: 8080
readinessProbe:
exec:
command:
- /bin/grpc_health_probe
- -addr=:8080
initialDelaySeconds: 2
EOF
Wait service ready
export CLUSTER2_GW_ADDR=$(kubectl get svc \
--selector=app=istio-internal-ingressgateway \
-n istio-system \
-o jsonpath='{.items[0].status.loadBalancer.ingress[0].ip}')
GRPC Client
kubectl cp istio-samples/sample-apps/grpc-greeter-go/client/grpc-client sleep:/grpc-client -c sleep
Test
kubectl exec -it sleep -- /grpc-client --address=greeter:8080 --insecure=true
Output (balance)
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-v76cq
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-v76cq
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-qdd7v
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-v76cq
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-v76cq
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-v76cq
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-qdd7v
2020/11/13 08:16:20 Hello world from greeter-68f4cd6c6-v76cq
Context switch
kubectl config use-context $CTX_CLUSTER1
Install Itsio
cd $ISTIO_PATH
kubectl create namespace istio-system
kubectl create secret generic cacerts -n istio-system \
--from-file=samples/certs/ca-cert.pem \
--from-file=samples/certs/ca-key.pem \
--from-file=samples/certs/root-cert.pem \
--from-file=samples/certs/cert-chain.pem
istioctl install \
-f manifests/examples/multicluster/values-istio-multicluster-gateways.yaml \
--set meshConfig.accessLogFile=/dev/stdout
cd -
Setup Cluster 1
kubectl apply -f - <<EOF
apiVersion: v1
kind: ConfigMap
metadata:
name: kube-dns
namespace: kube-system
data:
stubDomains: |
{
"global": ["$(kubectl get svc -n istio-system istiocoredns -o jsonpath={.spec.clusterIP})"],
"cluster-2": ["$(kubectl get svc -n istio-system istiocoredns -o jsonpath={.spec.clusterIP})"]
}
EOF
kubectl apply -f - <<EOF
apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
name: greeter-cluster-2
spec:
hosts:
- greeter.default.cluster-2
location: MESH_INTERNAL
ports:
- name: grpc
number: 8080
protocol: GRPC
resolution: DNS
addresses:
- 240.0.0.2
endpoints:
- address: ${CLUSTER2_GW_ADDR}
ports:
grpc: 15443
EOF
kubectl label namespace default istio-injection=enabled
kubectl apply -f cluster-1
GRPC Client
kubectl cp istio-samples/sample-apps/grpc-greeter-go/client/grpc-client sleep:/grpc-client -c sleep
Test
kubectl exec -it sleep -- /grpc-client --address=greeter.default.cluster-2:8080 --insecure=true
Output (Not balance)
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:16:42 Hello world from greeter-68f4cd6c6-z5dr4
Uncomment cluster-2/virtualservice.yaml: #- mesh
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: greeter
spec:
gateways:
- istio-internal-ingressgateway
- mesh
hosts:
- 'greeter'
- 'greeter.default.cluster-2'
- 'greeter.default.svc.cluster.local'
http:
- match:
- uri:
prefix: /
route:
- destination:
host: greeter
port:
number: 8080
Apply change
kubectl config use-context $CTX_CLUSTER2
kubectl apply -f cluster-2
Test
kubectl config use-context $CTX_CLUSTER1
kubectl exec -it sleep -- /grpc-client --address=greeter.default.cluster-2:8080 --insecure=true
Output (balance)
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-qdd7v
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-qdd7v
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-qdd7v
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-z5dr4
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-v76cq
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-qdd7v
2020/11/13 08:17:07 Hello world from greeter-68f4cd6c6-z5dr4