Introduction

Istio is a powerful service mesh that provides traffic management, security, and observability for microservices running on Kubernetes. This guide covers the installation of Istio on a Kubernetes cluster and its basic configuration to get started.

Prerequisites

Before installing Istio, ensure that you have the following:

• A running Kubernetes cluster (v1.21 or later)

• kubectl command-line tool configured for the cluster

• Helm (optional but recommended for managing Istio components)

Step 1: Download and Install Istio CLI

1. Download the latest Istio release:

    curl -L https://istio.io/downloadIstio | sh -
   

2. Move into the Istio directory:

    cd istio-*/
   

3. Add the Istio CLI (istioctl) to your system's PATH:

    export PATH=$PWD/bin:$PATH
   

Step 2: Install Istio in Kubernetes

Istio provides multiple installation profiles. The default profile is a good starting point.

1. Install Istio using the default profile:

    istioctl install --set profile=default -y
   

2. Verify that Istio components are running:

    kubectl get pods -n istio-system
   

Step 3: Enable Istio Sidecar Injection

Istio uses sidecar proxies to manage service communication. To enable automatic sidecar injection, label your namespace:

kubectl label namespace default istio-injection=enabled

This ensures that all new pods in the default namespace will have an Envoy sidecar proxy automatically injected.

Step 4: Deploy a Sample Application

1. Deploy the Istio sample application (bookinfo):

    kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml
   

2. Expose the application using the Istio ingress gateway:

    kubectl apply -f samples/bookinfo/networking/bookinfo-gateway.yaml
   

3. Retrieve the external IP of the Istio ingress gateway:

    kubectl get svc istio-ingressgateway -n istio-system
   

   Access the application using http://<EXTERNAL-IP>/productpage.

Step 5: Verify Istio Configuration

1. Check if services are managed by Istio:

    kubectl get svc,deploy,pods -n default
   

2. Inspect the Istio-proxy logs for a deployed pod:

    kubectl logs <pod-name> -c istio-proxy
   

Conclusion

Istio is now successfully installed and configured on your Kubernetes cluster. You can start leveraging its features for traffic management, security policies, and observability. For advanced configurations, explore Istio VirtualServices, DestinationRules, and mTLS settings.