Install Multi-Primary

Follow this guide to install the Istio control plane on both cluster1 and cluster2, making each a primary cluster. Both clusters reside on the network1 network, meaning there is direct connectivity between the pods in both clusters.

Before proceeding, be sure to complete the steps under before you begin.

In this configuration, each control plane observes the API Servers in both clusters for endpoints.

Service workloads communicate directly (pod-to-pod) across cluster boundaries.

Multiple primary clusters on the same network

Configure cluster1 as a primary

Create the Istio configuration for cluster1:

$ cat <<EOF > cluster1.yaml
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  values:
    global:
      meshID: mesh1
      multiCluster:
        clusterName: cluster1
      network: network1
EOF

Apply the configuration to cluster1:

$ istioctl install --context="${CTX_CLUSTER1}" -f cluster1.yaml

Configure cluster2 as a primary

Create the Istio configuration for cluster2:

$ cat <<EOF > cluster2.yaml
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  values:
    global:
      meshID: mesh1
      multiCluster:
        clusterName: cluster2
      network: network1
EOF

Apply the configuration to cluster2:

$ istioctl install --context="${CTX_CLUSTER2}" -f cluster2.yaml

Enable Endpoint Discovery

Install a remote secret in cluster2 that provides access to cluster1’s API server.

$ istioctl x create-remote-secret \
    --context="${CTX_CLUSTER1}" \
    --name=cluster1 | \
    kubectl apply -f - --context="${CTX_CLUSTER2}"

Install a remote secret in cluster1 that provides access to cluster2’s API server.

$ istioctl x create-remote-secret \
    --context="${CTX_CLUSTER2}" \
    --name=cluster2 | \
    kubectl apply -f - --context="${CTX_CLUSTER1}"

Congratulations! You successfully installed an Istio mesh across multiple primary clusters!

Next Steps

You can now verify the installation.

Cleanup

1. Uninstall Istio in cluster1:

   $ istioctl uninstall --context="${CTX_CLUSTER1}" -y --purge
   $ kubectl delete ns istio-system --context="${CTX_CLUSTER1}"

2. Uninstall Istio in cluster2:

   $ istioctl uninstall --context="${CTX_CLUSTER2}" -y --purge
   $ kubectl delete ns istio-system --context="${CTX_CLUSTER2}"