How to configure ingress gateway in istio? - kubernetes

Question

I'm new to istio, and I want to access my app through istio ingress gateway, but I do not know why it does not work.
This is my kubenetes_deploy.yaml file content:
apiVersion: v1
kind: Service
metadata:
name: batman
labels:
run: batman
spec:
#type: NodePort
ports:
- port: 8000
#nodePort: 32000
targetPort: 7000
#protocol: TCP
name: batman
selector:
run: batman
#version: v1
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: batman-v1
spec:
replicas: 1
selector:
matchLabels:
run: batman
template:
metadata:
labels:
run: batman
version: v1
spec:
containers:
- name: batman
image: leowu/batman:v1
ports:
- containerPort: 7000
env:
- name: MONGODB_URL
value: mongodb://localhost:27017/articles_demo_dev
- name: mongo
image: mongo
And here is my istio ingress_gateway.yaml config file:
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: batman-gateway
spec:
selector:
istio: ingressgateway
servers:
- port:
number: 15000
name: http
protocol: HTTP
hosts:
- "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: batman
spec:
hosts:
- "*"
gateways:
- batman-gateway
http:
- match:
route:
- destination:
host: batman
port:
number: 7000
I created the ingress gateway from example, and it looks well but when I run kubectl get svc istio-ingressgateway -n istio-system I can't see the listening port 15000 in the output。I donot know way.
Is there anyone can help me? Thanks.

Answer 1

First of all, as #Abhyudit Jain mentioned you need to correct port in VirtualService to 8000
And then you just add another port to your istio-ingressgateway service
kubectl edit svc istio-ingressgateway -n istio-system
add section:
ports:
- name: http
nodePort: 30001
port: 15000
protocol: TCP
targetPort: 80
This will accept HTTP traffic on port 15000 and rout it to your destination service on port 8000
simple schema as follows:
incoming traffic --> istio-gateway service --> istio-gateway --> virtual service --> service --> pod

Answer 2

You batman service listens on port 8000 and forwards traffic to container's port 7000.
The istio traffic works like this:
ingress-gateway -> virtual-service -> destination-rule [optional] -> service
So your virtual service should be like:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: batman
spec:
hosts:
- "*"
gateways:
- batman-gateway
http:
- match:
route:
- destination:
host: batman
port:
number: 8000 <--- change