Exposing services through Istio Ingress Gateway

The components deployed on the service mesh by default are not exposed outside the cluster. An Ingress Gateway is deployed as a Kubernetes service of type LoadBalancer (or NodePort). To make Bookinfo accessible external to the cluster, you have to create an Istio Gateway for the Bookinfo application and also define an Istio VirtualService with the routes we need.

Inspecting the Istio Ingress Gateway

kubectl get svc istio-ingressgateway -n istio-system -o yaml

Because the Istio Ingress Gateway is an Envoy Proxy you can inspect it using the admin routes. First find the name of the istio-ingressgateway:

kubectl get pods -n istio-system

Copy and paste your ingress gateway’s pod name. Execute:

kubectl -n istio-system exec -it <istio-ingressgateway-...> bash

You can view the statistics, listeners, routes, clusters and server info for the Envoy proxy by forwarding the local port:

curl localhost:15000/help
curl localhost:15000/stats
curl localhost:15000/listeners
curl localhost:15000/clusters
curl localhost:15000/server_info

See the admin docs for more details.

Also it can be helpful to look at the log files of the Istio ingress controller to see what request is being routed.

Before we check the logs, let us get out of the container back on the host:

exit

Now let us find the ingress pod and output the log:

kubectl logs istio-ingressgateway-... -n istio-system

View Istio Ingress Gateway for Bookinfo

View the Gateway and VirtualServices

Check the created Istio Gateway and Istio VirtualService to see the changes deployed:

kubectl get gateway
kubectl get gateway -o yaml

kubectl get virtualservices
kubectl get virtualservices -o yaml

Find the external port of the Istio Ingress Gateway by running:

kubectl get service istio-ingressgateway -n istio-system -o wide

To just get the first port of istio-ingressgateway service, we can run this:

kubectl get service istio-ingressgateway -n istio-system --template='{{(index .spec.ports 1).nodePort}}'

Create a DNS entry:

Modify you local /etc/hosts file to add an entry for your sample application.

127.0.0.1. bookinfo.meshery.io

The HTTP port is usually 31380.

Or run these commands to retrieve the full URL:

echo "http://$(kubectl get nodes --selector=kubernetes.io/role!=master -o jsonpath={.items[0].status.addresses[?\(@.type==\"InternalIP\"\)].address}):$(kubectl get svc istio-ingressgateway -n istio-system -o jsonpath='{.spec.ports[1].nodePort}')/productpage"

Docker Desktop users please use http://localhost/productpage to access product page in your browser.

In case you are using a managed kubernetes cluster like AKS, EKS, or GCE please follow the procedure described below:

• Get the external IP of the service istio-ingressgateway using the following command:

  kubectl get service istio-ingressgateway -n istio-system
  

• Using Meshery, navigate to the Custom yaml page, and apply the manifest given below to allow all hosts instead of allowing bookinfo.meshery.io only and you are good to access the page using the following url http://<external-ip of istio-ingressgateway>/productpage.

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: bookinfo
spec:
  gateways:
    - sample-app-gateway
  hosts:
    - "*"
  http:
    - match:
        - uri:
            exact: /productpage
        - uri:
            prefix: /static
        - uri:
            exact: /login
        - uri:
            exact: /logout
        - uri:
            prefix: /api/v1/products
      route:
        - destination:
            host: productpage
            port:
              number: 9080

Apply default destination rules

Before we start playing with Istio’s traffic management capabilities we need to define the available versions of the deployed services. They are called subsets, in destination rules.

Using Meshery, navigate to the Custom yaml page, and apply the below to create the subsets for BookInfo:

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: productpage
spec:
  host: productpage
  subsets:
    - name: v1
      labels:
        version: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  subsets:
    - name: v1
      labels:
        version: v1
    - name: v2
      labels:
        version: v2
    - name: v3
      labels:
        version: v3
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: ratings
spec:
  host: ratings
  subsets:
    - name: v1
      labels:
        version: v1
    - name: v2
      labels:
        version: v2
    - name: v2-mysql
      labels:
        version: v2-mysql
    - name: v2-mysql-vm
      labels:
        version: v2-mysql-vm
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: details
spec:
  host: details
  subsets:
    - name: v1
      labels:
        version: v1
    - name: v2
      labels:
        version: v2

This creates destination rules for each of the BookInfo services and defines version subsets

In a few seconds we should be able to verify the destination rules created by using the command below:

kubectl get destinationrules


kubectl get destinationrules -o yaml

Browse to BookInfo

Browse to the website of the Bookinfo. To view the product page, you will have to append /productpage to the url.

Reload Page

Now, reload the page multiple times and notice how it round robins between v1, v2 and v3 of the reviews service.

Inspect the Istio proxy of the productpage pod

To better understand the istio proxy, let’s inspect the details. Let us exec into the productpage pod to find the proxy details. To do so we need to first find the full pod name and then exec into the istio-proxy container:

kubectl get pods
kubectl exec -it productpage-v1-... -c istio-proxy  sh

Once in the container look at some of the envoy proxy details by inspecting it’s config file:

ps aux
ls -l /etc/istio/proxy
cat /etc/istio/proxy/envoy-rev0.json

For more details on envoy proxy please check out their admin docs.

As a last step, lets exit the container:

exit

Alternative: Manual installation

Default destination rules

Run the following command to create default destination rules for the Bookinfo services:

kubectl apply -f samples/bookinfo/networking/destination-rule-all-mtls.yaml

Configure the Bookinfo route with the Istio Ingress gateway

We can create a virtualservice & gateway for bookinfo app in the ingress gateway by running the following:

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