K8s-Ingress.md

LAB: K8s Ingress

This scenario shows how K8s ingress works on minikube. When browsing urls, ingress controller (nginx) directs traffic to the related services.

(ref: Kubernetes.io)

Steps

• Run minikube on Windows Hyperv or Virtualbox. In this scenario:

minikube start --driver=hyperv 
or
minikube start --driver=hyperv --force-systemd

• To install ingress controller on K8s cluster, please visit to learn: https://kubernetes.github.io/ingress-nginx/deploy/

• On Minikube, it is only needed to enable ingress controller.

minikube addons enable ingress
minikube addons list

• Copy and save (below) as file on your PC (appingress.yaml).
• File: https://github.com/omerbsezer/Fast-Kubernetes/blob/main/labs/ingress/appingress.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: appingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
  rules:
    - host: webapp.com
      http:
        paths:
          - path: /blue
            pathType: Prefix
            backend:
              service:
                name: bluesvc
                port:
                  number: 80
          - path: /green
            pathType: Prefix
            backend:
              service:
                name: greensvc
                port:
                  number: 80

• Copy and save (below) as file on your PC (todoingress.yaml).
• File: https://github.com/omerbsezer/Fast-Kubernetes/blob/main/labs/ingress/todoingress.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: todoingress
spec:
  rules:
    - host: todoapp.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: todosvc
                port:
                  number: 80

• Copy and save (below) as file on your PC (deploy.yaml).
• File: https://github.com/omerbsezer/Fast-Kubernetes/blob/main/labs/ingress/deploy.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: blueapp
  labels:
    app: blue
spec:
  replicas: 2
  selector:
    matchLabels:
      app: blue
  template:
    metadata:
      labels:
        app: blue
    spec:
      containers:
      - name: blueapp
        image: ozgurozturknet/k8s:blue
        ports:
        - containerPort: 80
        livenessProbe:
          httpGet:
            path: /healthcheck
            port: 80
          initialDelaySeconds: 5
          periodSeconds: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: 80
          initialDelaySeconds: 5
          periodSeconds: 3
---
apiVersion: v1
kind: Service
metadata:
  name: bluesvc
spec:
  selector:
    app: blue
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: greenapp
  labels:
    app: green
spec:
  replicas: 2
  selector:
    matchLabels:
      app: green
  template:
    metadata:
      labels:
        app: green
    spec:
      containers:
      - name: greenapp
        image: ozgurozturknet/k8s:green
        ports:
        - containerPort: 80
        livenessProbe:
          httpGet:
            path: /healthcheck
            port: 80
          initialDelaySeconds: 5
          periodSeconds: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: 80
          initialDelaySeconds: 5
          periodSeconds: 3
---
apiVersion: v1
kind: Service
metadata:
  name: greensvc
spec:
  selector:
    app: green
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: todoapp
  labels:
    app: todo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: todo
  template:
    metadata:
      labels:
        app: todo
    spec:
      containers:
      - name: todoapp
        image: ozgurozturknet/samplewebapp:latest
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: todosvc
spec:
  selector:
    app: todo
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

• Run "deploy.yaml" and "appingress.yaml" to create deployments and services

• Add url-ip on Windows/System32/Drivers/etc/hosts file:

• When running on browser the url "webapp.com/blue", one of the blue app containers return response.

• When running on browser the url "webapp.com/green", one of the green app containers return response.

• When running on browser, "todoapp.com":

• Hence, we can open services running on the cluster with one IP to the out of the cluster.

• Delete all yaml file and minikube.

References

https://github.com/aytitech/k8sfundamentals/tree/main/ingress