Installing Istio on OVHcloud Managed Kubernetes

Last updated 30th May, 2022.

Istio is a open source service mesh and platform to reduce the complexity of deploying, securing, controlling and observing distributed services. As the Istio site explains, Istio helps you to:

• Control the flow of traffic between services
• Secure the services and manage the authentication, authorization and encryption of inter-service communications
• Apply and enforce policies on distributes services
• Monitor the services gathering metrics, logs and traces

In this tutorial we are going to install Istio on a freshly created OVHcloud Managed Kubernetes Service cluster. You can use the Reset cluster function in the Public Cloud section of the OVHcloud Control Panel to reinitialize your cluster before following this tutorial.

Before you begin

This tutorial presupposes that you already have a working OVHcloud Managed Kubernetes cluster, and some basic knowledge of how to operate it. If you want to know more on those topics, please look at the deploying a Hello World application documentation.

Downloading Istio

Istio is installed in its own istio-system namespace and can manage services from all other namespaces.

1. Go to the Istio release page to download the installation file for your OS, or download and extract the latest release automatically (Linux or macOS):

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

2. Move to the Istio package directory. For example, if the package is istio-1.11.2:

   cd istio-1.11.2

   The installation directory contains:

   • Sample applications in samples/
   • The istioctl client binary in the bin/ directory.

3. Add the istioctl client to your PATH environment variable, on a macOS or Linux system:

   export PATH=$PWD/bin:$PATH

For the rest of the tutorial, please remain on this directory.

Installing Istio

For this installation, we use the istioctl command line tool that provides rich customization of the Istio control plane and of the sidecars for the Istio data plane. It has user input validation to help prevent installation errors and customization options to override any aspect of the configuration.

In this tutorial you're going to install Istio with the default profile, other profiles exists.

istioctl install

$ istioctl install
This will install the Istio 1.11.2 default profile with ["Istio core" "Istiod" "Ingress gateways"] components into the cluster. Proceed? (y/N) y
✔ Istio core installed
✔ Istiod installed
✔ Ingress gateways installed
✔ Installation complete
Thank you for installing Istio 1.11.  Please take a few minutes to tell us about your install/upgrade experience!  https://forms.gle/kWULBRjUv7hHci7T6

The istio-system namespace is created with all Istio components.

Installing Addons

Istio integrates several different telemetry applications. These can help you gain an understanding of the structure of your service mesh, display the topology of the mesh, and analyze the health of your mesh.

Use the following instructions to deploy the Kiali dashboard, along with Prometheus, Grafana, and Jaeger.

Install Kiali and the other addons and wait for them to be deployed:

kubectl apply -f samples/addons

In my example cluster I get:

$ kubectl apply -f samples/addons
serviceaccount/grafana created
configmap/grafana created
service/grafana created
deployment.apps/grafana created
configmap/istio-grafana-dashboards created
configmap/istio-services-grafana-dashboards created
deployment.apps/jaeger created
service/tracing created
service/zipkin created
service/jaeger-collector created
...
service/prometheus created
deployment.apps/prometheus created

Verifying the installation

1. List the services in istio-system namespace using kubectl get services -n istio-system and ensure that the following services are deployed: istiod, istio-ingressgateway and the addons: grafana, jaeger, kiali, prometheus, tracingand zipkin.

   In my example cluster I get:

   $  kubectl get services -n istio-system
   NAME                   TYPE           CLUSTER-IP     EXTERNAL-IP     PORT(S)                                      AGE
   grafana                ClusterIP      10.3.75.230              3000/TCP                                     2m19s
   istio-ingressgateway   LoadBalancer   10.3.175.205   51.178.69.212   15021:31288/TCP,80:32588/TCP,443:30085/TCP   4m38s
   istiod                 ClusterIP      10.3.31.181              15010/TCP,15012/TCP,443/TCP,15014/TCP        4m49s
   jaeger-collector       ClusterIP      10.3.250.26              14268/TCP,14250/TCP,9411/TCP                 2m16s
   kiali                  ClusterIP      10.3.255.49              20001/TCP,9090/TCP                           2m15s
   prometheus             ClusterIP      10.3.9.246               9090/TCP                                     2m15s
   tracing                ClusterIP      10.3.220.9               80/TCP,16685/TCP                             2m16s
   zipkin                 ClusterIP      10.3.165.183             9411/TCP                                     2m16s
   

   As the LoadBalancer creation is asynchronous, and the provisioning of the load balancer can take several minutes, you will surely get a pending for istio-ingressgateway EXTERNAL-IP field. Please try again in a few minutes to get the external URL to call your Istio.

2. List the pods in istio-system namespace using kubectl get pods -n istio-system and ensure that the following pods are deployed and all containers are up and running: istiod-*, istio-ingressgateway-* and the addons: grafana-*, jaeger-*, kiali-*and prometheus-*.

   In my example cluster I get:

   $ kubectl get pods -n istio-system
   NAME                                    READY   STATUS    RESTARTS   AGE
   grafana-556f8998cd-kmn6l                1/1     Running   0          4m23s
   istio-ingressgateway-65668fd4dd-t8t4q   1/1     Running   0          6m43s
   istiod-5f7bb95ddf-25f27                 1/1     Running   0          6m54s
   jaeger-5f65fdbf9b-ctjkn                 1/1     Running   0          4m20s
   kiali-787bc487b7-h9ck9                  1/1     Running   0          4m19s
   prometheus-9f4947649-7wszv              2/2     Running   0          4m19s
   

Deploying an application

To verify that Istio is truly working in the cluster, you are going to deploy a test application. We have choosen the Bookinfo application, as it's a multi-technology multi-instance microservices-based application that let's you verify if Istio works as intended.

Installing Bookinfo

The Istio-Sidecar-injector, that you installed with Istio, will automatically inject Envoy containers into your application pods. The injector assumes the application pods are running in namespaces labeled with istio-injection=enabled.

Let's create and label a istio-apps namespace:

kubectl create namespace istio-apps

Then, add the istio-injection=enabled label:

kubectl label namespace istio-apps istio-injection=enabled

In my example cluster I get:

$ kubectl create namespace istio-apps
namespace/istio-apps created

$ kubectl label namespace istio-apps istio-injection=enabled
namespace/istio-apps labeled

And now, deploy the bookinfo manifest into the namespace:

kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml -n istio-apps

The above command installs and launches, in istio-apps namespace, all four microservices as illustrated in the above diagram: details, productpage, ratings and the three versions of reviews:

$ kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml -n istio-apps
service/details created
serviceaccount/bookinfo-details created
deployment.apps/details-v1 created
service/ratings created
serviceaccount/bookinfo-ratings created
deployment.apps/ratings-v1 created
service/reviews created
serviceaccount/bookinfo-reviews created
deployment.apps/reviews-v1 created
deployment.apps/reviews-v2 created
deployment.apps/reviews-v3 created
service/productpage created
serviceaccount/bookinfo-productpage created
deployment.apps/productpage-v1 created

Now you can verify that all services and pods are correctly defined and running:

1. Use kubectl -n istio-apps get services to verify that the details, productpage, ratings and reviews services are up un running:

   $ kubectl -n istio-apps get services
   NAME          TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
   details       ClusterIP   10.3.131.63            9080/TCP   6s
   productpage   ClusterIP   10.3.141.189           9080/TCP   4s
   ratings       ClusterIP   10.3.133.82            9080/TCP   5s
   reviews       ClusterIP   10.3.60.119            9080/TCP   5s
   

2. Use kubectl -n istio-apps get pods to verify that the details-v1-*, productpage-v1-*, ratings-v1-*, reviews-v1-*, reviews-v2-* and reviews-v3-* are up and running:

   In the case of my example cluster:

   $ kubectl -n istio-apps get pods
   NAME                              READY   STATUS    RESTARTS   AGE
   details-v1-79f774bdb9-wnklv       2/2     Running   0          88s
   productpage-v1-6b746f74dc-4d77c   2/2     Running   0          87s
   ratings-v1-b6994bb9-s6kwq         2/2     Running   0          88s
   reviews-v1-545db77b95-rf58h       2/2     Running   0          88s
   reviews-v2-7bf8c9648f-5dt4x       2/2     Running   0          88s
   reviews-v3-84779c7bbc-f5jbw       2/2     Running   0          87s
   

As you can see, each pod has 2 containers, the app container and the Istio sidecar that is deployed with it.

Verify everything is working correctly up to this point. Run this command to see if the app is running inside the cluster and serving HTML pages by checking for the page title in the response:

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

Open the application to outside traffic

Now that the Bookinfo services are up and running, you need to make the application accessible from outside of your Kubernetes cluster, e.g., from a browser. An Istio Gateway is used for this purpose.

1. Associate this application with the Istio gateway:

   $ kubectl apply -f samples/bookinfo/networking/bookinfo-gateway.yaml -n istio-apps
   gateway.networking.istio.io/bookinfo-gateway created
   virtualservice.networking.istio.io/bookinfo created
   

2. Ensure that there are no issues with the configuration:

   $ istioctl analyze -n istio-apps
   ✔ No validation issues found when analyzing namespace: istio-apps.
   

3. Confirm the gateway has been created:

   $ kubectl -n istio-apps get gateway
   NAME               AGE
   bookinfo-gateway   53s
   

Determining the ingress IP and port

Set GATEWAY_URL, the URL of the istio-gateway service.

You can get it with the following commands:

$ 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 GATEWAY_URL=$INGRESS_HOST:$INGRESS_PORT

$ echo $GATEWAY_URL
135.125.84.93

Confirm the app is running

To confirm that the Bookinfo application is running, run the following curl command:

curl -o /dev/null -s -w "%{http_code}\n"  http://$GATEWAY_URL/productpage

You should get an HTTP status code 200 indicating that your productpage is OK.

$ curl -o /dev/null -s -w "%{http_code}\n"  http://$GATEWAY_URL/productpage
200

You can also point your browser to http://<YOUR_GATEWAY_URL>/productpage (in my example to http://135.125.84.93:80/productpage) to view the Bookinfo web page. If you refresh the page several times, you should see different versions of reviews shown in productpage, presented in a round robin style (red stars, black stars, no stars), since we haven’t yet used Istio to control the version routing.

Visualize the traffic

As we installed Istio addons, we can access the Kiali dashboard. The following command will create a tunnel between the Kiali service and your machine and then open the dashboard link in your favorite browser:

istioctl dashboard kiali

Now, we will take a look to the traffic. For that, in the left navigation menu, select Graph and in the Namespace drop down, select istio-apps.

The Kiali dashboard shows an overview of your mesh with the relationships between the services in the Bookinfo sample application. It also provides filters to visualize the traffic flow.

What's next?

Now you have a working Bookinfo app deployed on Istio, you can follow the suggestions of the Bookinfo sample app page and use this sample to experiment with Istio’s features for traffic routing, fault injection, rate limiting, etc. To proceed, refer to one or more of the Istio Examples, depending on your interest. Intelligent Routing is a good place to start for beginners.

Cleanup

To uninstall the Bookinfo app, the easiest way is to use the provided cleanup.sh script:

$ ./samples/bookinfo/platform/kube/cleanup.sh
namespace ? [default] istio-apps
using NAMESPACE=istio-apps
virtualservice.networking.istio.io "bookinfo" deleted
gateway.networking.istio.io "bookinfo-gateway" deleted
Application cleanup may take up to one minute
service "details" deleted
serviceaccount "bookinfo-details" deleted
deployment.apps "details-v1" deleted
service "ratings" deleted
serviceaccount "bookinfo-ratings" deleted
deployment.apps "ratings-v1" deleted
service "reviews" deleted
serviceaccount "bookinfo-reviews" deleted
deployment.apps "reviews-v1" deleted
deployment.apps "reviews-v2" deleted
deployment.apps "reviews-v3" deleted
service "productpage" deleted
serviceaccount "bookinfo-productpage" deleted
deployment.apps "productpage-v1" deleted
Application cleanup successful

To confirm the shutdown you can list the virtual services, destination rules, gateway and pods in the istio-apps namespace:

kubectl -n istio-apps get virtualservices   #-- there should be no virtual services
kubectl -n istio-apps get destinationrules  #-- there should be no destination rules
kubectl -n istio-apps get gateway           #-- there should be no gateway
kubectl -n istio-apps get pods              #-- there should be no pod

In my example cluster:

$ kubectl -n istio-apps get virtualservices   #-- there should be no virtual services
No resources found in istio-apps namespace.
kubectl -n istio-apps get destinationrules  #-- there should be no destination rules
No resources found in istio-apps namespace.
kubectl -n istio-apps get gateway           #-- there should be no gateway
No resources found in istio-apps namespace.
kubectl -n istio-apps get pods              #-- there should be no pod
No resources found in istio-apps namespace.

Now you can uninstall Istio with istioctl command:

istioctl manifest generate | kubectl delete --ignore-not-found=true -f -

This command deletes the RBAC permissions and all resources hierarchically under the istio-system namespace. It is safe to ignore errors for non-existent resources because they may have been deleted hierarchically.

The istio-system namespace is not removed by default. If no longer needed, use the following command to remove it:

kubectl delete namespace istio-system

And remove istio-apps namespace:

kubectl delete namespace istio-apps

Example on my cluster:

$ istioctl manifest generate | kubectl delete --ignore-not-found=true -f -
customresourcedefinition.apiextensions.k8s.io "authorizationpolicies.security.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "destinationrules.networking.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "envoyfilters.networking.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "gateways.networking.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "istiooperators.install.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "peerauthentications.security.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "requestauthentications.security.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "serviceentries.networking.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "sidecars.networking.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "telemetries.telemetry.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "virtualservices.networking.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "workloadentries.networking.istio.io" deleted
customresourcedefinition.apiextensions.k8s.io "workloadgroups.networking.istio.io" deleted
serviceaccount "istio-ingressgateway-service-account" deleted
serviceaccount "istio-reader-service-account" deleted
serviceaccount "istiod" deleted
serviceaccount "istiod-service-account" deleted
clusterrole.rbac.authorization.k8s.io "istio-reader-clusterrole-istio-system" deleted
clusterrole.rbac.authorization.k8s.io "istio-reader-istio-system" deleted
clusterrole.rbac.authorization.k8s.io "istiod-clusterrole-istio-system" deleted
...
service "istio-ingressgateway" deleted
service "istiod" deleted

$ kubectl delete namespace istio-system
namespace "istio-system" deleted

$ kubectl delete namespace istio-apps
namespace "istio-apps" deleted

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