Before you begin

In addition, review the requirements and perform the initial steps below.

This guide requires that you have two Kubernetes clusters with any of the supported Kubernetes versions: 1.18, 1.19, 1.20, 1.21.

API Server Access

The API Server in each cluster must be accessible to the other clusters in the mesh. Many cloud providers make API Servers publicly accessible via network load balancers (NLB). If the API Server is not directly accessible, you will have to modify the installation procedure to enable access. For example, the gateway used in the multi-network and primary-remote configurations could also be used to enable access to the API Server.

This guide will refer to two clusters: and cluster2. The following environment variables will be used throughout to simplify the instructions:

A multicluster service mesh deployment requires that you establish trust between all clusters in the mesh. Depending on the requirements for your system, there may be multiple options available for establishing trust. See certificate management for detailed descriptions and instructions for all available options. Depending on which option you choose, the installation instructions for Istio may change slightly.

This guide will assume that you use a common root to generate intermediate certificates for each cluster. Follow the to generate and push a CA certificate secret to both the and cluster2 clusters.

If you currently have a single cluster with a self-signed CA (as described in Getting Started), you need to change the CA using one of the methods described in . Changing the CA typically requires reinstalling Istio. The installation instructions below may have to be altered based on your choice of CA.

You’re now ready to install an Istio mesh across multiple clusters. The particular steps will depend on your requirements for network and control plane topology.

See for more information.