Ingress Netorking

Ingress Netorking
---------------


You do not have an Ingress Controller on k8s by default, so you need to install one (GCP Load Balancer, Nginx, Contour, HAProxy, traefik, Istio)

nginx-ingress-controller.yaml
---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-ingress-constroller
spec:
  replicas: 1
  selector:
    matchLabels: 
      name: nginx-ingress
  template:
    metadata:
      labels:
        name: nginx-ingress
    spec:
      containers:
        - name: nginx-ingress-constroller
          image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.21.0
      args:
        - /nginx-ingress-controller
        - --configmap=$(POD_NAMESPACE)/nginx-controller
      env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.POD_NAME
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace

      ports:
        - name: http
          containerPort: 80
        - name: https
          containerPort: 443


config-map.yaml
---

kind: ConfigMap
apiVersion: v1
metadata:
  name: nginx-configuration



service-nginx-ingress.yaml
---

apiversion: v1
kind: Service
metadata:
  name: nginx-ingress
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
    name: http
  - port: 443
    targetPort: 443
    protocol: TCP
    name: https
  selector:
    name: nginx-ingress

service-account.yaml
---

apiVersion: v1
kind: ServiceAccount
metadata:
  name: nginx-ingress-serviceaccount
spec:



Creating Ingress ressources
--------------------------

set of rules and configurations applied on the ingress nginx-ingress-controller

ingress-wear.yaml
---

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-wear
spec:
  backend:
    serviceName: wear-service
    servicePort: 80

> kubectl create -f ingress-wear.yaml
> kubectl get ingress


ingress-wear-watch.yaml
----------

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-wear-watch
spec:
  rules:
  - http:
      paths:
      - path: /wear
        backend:
          serviceName: wear-service
          servicePort: 80
      - path: /watch
        backend:
          serviceName: watch-service
          servicePort: 80

> kubectl create -f ingress-wear-watch.yaml


using domain names
------

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-wear-watch
spec:
  rules:
  - host: wear.my-online-store.com
    http:
      paths:
      - backend:
          serviceName: wear-service
          servicePort: 80
  - host: wear.my-online-store.com
    http:
      paths:
      - backend:
          serviceName: watch-service
          servicePort: 80



We can now create an ingress resource in an imperative way :

Format - kubectl create ingress <ingress-name> --rule="host/path=service:port"

Example - kubectl create ingress ingress-test --rule="wear.my-online-store.com/wear*=wear-service:80"


Find more information and examples in the below reference link:-

https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#-em-ingress-em- 

References:-

https://kubernetes.io/docs/concepts/services-networking/ingress

https://kubernetes.io/docs/concepts/services-networking/ingress/#path-types

PRACTICE
------



pay-ingress.yaml
--
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
  name: pay-ingress
  namespace: critical-space
spec:
  rules:
  - http:
      paths:
      - backend:
          service:
            name: pay-service
            port:
              number: 8282
        path: /pay
        pathType: Prefix


wear-watch.yaml
---

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
  generation: 1
  name: ingress-wear-watch
  namespace: app-space

spec:
  rules:
  - http:
      paths:
      - backend:
          service:
            name: wear-service
            port:
              number: 8080
        path: /wear
        pathType: Prefix
      - backend:
          service:
            name: video-service
            port:
              number: 8080
        path: /stream
        pathType: Prefix
      - backend:
          service:
            name: food-service
            port:
              number: 8080
        path: /eat
        pathType: Prefix

--

pay-ingress.yaml
--
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
  name: shop-ingress
  namespace: app-space
spec:
  rules:
  - http:
      paths:
      - backend:
          service:
            name: video-service
            port:
              number: 8080
        path: /watch
        pathType: Prefix
      - backend:
          service:
            name: wear-service
            port:
              number: 8080
        path: /wear
        pathType: Prefix