Install and use Istio in Kubernetes

What is Istio? It is a service mesh that placed into existing distributed applications. Istio includes APIs that let it integrate into any logging platform, or telemetry or policy system and lets you successfully, and efficiently, run a distributed microservices architecture, and provides a uniform way to secure, connect, and monitor microservices.

In this tutorial we will install Istio in Kubernetes, deploy the Bookinfo application used to demonstrate various Istio features and getting access to observability console for Istio - Kiali.

Create new Kubernetes cluster
Get access to your cluster using cli
Install Istio
Deploying Bookinfo application
Geting access to Bookinfo application
Getting access to Kiali

Create new Kubernetes cluster

Now you can create new cluster using this article: Kubernetes Cluster

Use next parameters for your cluster:

Master count: 1
Node count: 3
Docker volume size (GB): 30
Node flavor: VC-4
Master node flavor: VC-2

Get access to your cluster using cli

Now you can getting access to your cluster using this article Access to Kubernetes Cluster using CLI

Install Istio

Follow these steps to install Istio:

1) Download the release from the Istio releases page:

wget https://github.com/istio/istio/releases/download/1.4.0/istio-1.4.0-linux.tar.gz

tar -xvf istio-1.4.0-linux.tar.gz

2) Move to the Istio package direction:

cd istio-1.4.0

3) Add the istioctl client to your path:

export PATH=$PWD/bin:$PATH

4) Install Istio:

istioctl manifest apply --set profile=demo

5) Verify that all Istio services are deployed and pods are in running state:

kubectl get svc -n istio-system

kubectl get pods -n istio-system

Deploying Bookinfo application

Bookinfo application
The application which composed of four separate microservices used to demonstrate various Istio features. The application displays information about a book, similar to a single catalog entry of an online book store. Displayed on the page is a description of the book, book details (ISBN, number of pages, and so on), and a few book reviews.

1) Label the namespace that will host the application:

kubectl label namespace default istio-injection=enabled

2) Deploy your application using the kubectl command:

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

3) Verify that all services are deployed and pods are in running state:

kubectl get svc

kubectl get pods

4) Verify that the Bookinfo application is running:

kubectl exec -it $(kubectl get pod -l app=ratings -o jsonpath='{.items[0].metadata.name}') -c ratings -- curl productpage:9080/productpage | grep -o "<title>.*</title>"

Geting access to Bookinfo application

1) Define the ingress gateway for the application:

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

2) Confirm the gateway has been created:

kubectl get gateway

3) Set the INGRESS_HOST and INGRESS_PORT variables for accessing the gateway:

export INGRESS_HOST=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
export INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].port}')
export SECURE_INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="https")].port}')

4) Set GATEWAY_URL:

export GATEWAY_URL=$INGRESS_HOST:$INGRESS_PORT

5) Confirm that the Bookinfo application is accessible from outside the cluster, run the following curl command:

curl -s http://${GATEWAY_URL}/productpage | grep -o "<title>.*</title>"

Now we can view the Bookinfo web page following this staps:

1) Get the LoadBalancer’s IP:

kubectl get svc -n istio-system istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].ip}'

2) Navigate to http://<LoadBalancer's IP>/productpage

Getting access to Kiali

Kiali is an observability console for Istio with service mesh configuration capabilities. It helps you to understand the structure of your service mesh by inferring the topology, and also provides the health of your mesh.

For getting access to Kiali we need apply next yaml configuration to expose the tracing service:

 cat <<EOF | kubectl apply -f -
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: tracing-gateway
  namespace: istio-system
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 15032
      name: http-tracing
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: tracing-vs
  namespace: istio-system
spec:
  hosts:
  - "*"
  gateways:
  - tracing-gateway
  http:
  - match:
    - port: 15032
    route:
    - destination:
        host: tracing
        port:
          number: 80
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: tracing
  namespace: istio-system
spec:
  host: tracing
  trafficPolicy:
    tls:
      mode: DISABLE
---
EOF