Service Mesh on Kubernetes - Chapter 1 - Installing Istio in Kubernetes (English)

Bài viết tiếng Việt - Bài 1 - Cài đặt Istio vào Kubernetes

In the previous article, we learned about the concept of Service Mesh and What is Isito. From this article we will go into practice, in the first lesson we will learn how to install Istio into Kubernetes.

I refer to this series from the book Istio In Action, you can read it first without having to wait for my series.

How to install Istio?

To install Istio into Kubernetes we can use one of three ways:

• Using the istioctl
• Using istio-operator
• Use Helm to install Istio Helm Chart

In this article we will use istioctl.

Install istioctl

Visit release page https://github.com/istio/istio/releases and check latest version.

Run this handy script to download:

curl -L https://istio.io/downloadIstio | ISTIO_VERSION=1.15.1 sh -

mv istio-1.15.1/bin/istioctl /user/local/bin

Run the istioctl to verify that everything works:

istioctl version

let’s verify that any prerequisites have been met in our Kubernetes cluster before we begin installation.

istioctl x precheck

✔ No issues found when checking the cluster. Istio is safe to install or upgrade!
  To get started, check out https://istio.io/latest/docs/setup/getting-started/

Installing the Istio components into Kubernetes

We can use istioctl, istio-operator, or Helm to install Istio. In this tutorial, we use istioctl.

To perform the demo install, use the istioctl CLI tool as shown next:

istioctl install --set profile=demo -y

✔ Istio core installed
✔ Istiod installed
✔ Egress gateways installed
✔ Ingress gateways installed
✔ Installation complete

After done, we can run the kubectl to list all of the Pods in the istio-system namespace.

kubectl get pod -n istio-system

NAME                                    READY   STATUS    RESTARTS   AGE
istio-egressgateway-65b6c9d675-4gf7d    1/1     Running   0          2m45s
istio-ingressgateway-6984cfd6ff-b7tql   1/1     Running   0          2m45s
istiod-74bd9b9864-t7sn9                 1/1     Running   0          3m11s

You notice the Istio control plane there is only a single replica or instance. “This appears to be a single point of failure. What happens if these components fail or go down?”

The Istio control plane is intended to be deployed in a highly available architecture.

We can run the verify-install command post install to verify that it has completed successfully:

istioctl verify-install

Istio control-plane has some addons, for example, Grafana and Jaeger. For demo purposes only.

Install Prometheus

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.15/samples/addons/prometheus.yaml

Install Grafana

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.15/samples/addons/grafana.yaml

Install Jaeger

kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.15/samples/addons/jaeger.yaml

After the installation is complete, the architecture of Istio will be as shown below.

Now we can write a configuration file to create Istio resources, for example VirtualService in Istio:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews-route
spec:
  hosts:
  - reviews.prod.svc.cluster.local
  http:
  - headers:
      request:
        set:
          test: "true"
    route:
    - destination:
        host: reviews.prod.svc.cluster.local
        subset: v2
      weight: 25
    - destination:
        host: reviews.prod.svc.cluster.local
        subset: v1
      headers:
        response:
          remove:
          - foo
      weight: 75

Conclusion

So we have installed Istio into Kuberntes and its components successfully, in the next lesson we will start to learn and make the first example of how to use Istio.

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