Hướng dẫn sử dụng ingress nginx và control ingress bằng annotations trên k8s

Links video:

Nếu theo như video thì cài ingress nginx thông qua helm.

Hoặc cách các file yaml qua đây:

https://xuanthulab.net/trien-khai-nginx-ingress-controller-trong-kubernetes.html

Links git trong video nằm ở đây:

https://github.com/justmeandopensource/kubernetes/tree/master/yamls/ingress-demo

Ta có 3 file deployment tượng trưng cho 3 web khách nhau:

nginx-deploy-main.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: nginx
  name: nginx-deploy-main
spec:
  replicas: 1
  selector:
    matchLabels:
      run: nginx-main
  template:
    metadata:
      labels:
        run: nginx-main
    spec:
      containers:
      - image: nginx
        name: nginx
---

nginx-deploy-green.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: nginx
  name: nginx-deploy-green
spec:
  replicas: 1
  selector:
    matchLabels:
      run: nginx-green
  template:
    metadata:
      labels:
        run: nginx-green
    spec:
      volumes:
      - name: webdata
        emptyDir: {}
      initContainers:
      - name: web-content
        image: busybox
        volumeMounts:
        - name: webdata
          mountPath: "/webdata"
        command: ["/bin/sh", "-c", 'echo "<h1>I am <font color=green>GREEN</font></h1>" > /webdata/index.html']
      containers:
      - image: nginx
        name: nginx
        volumeMounts:
        - name: webdata
          mountPath: "/usr/share/nginx/html"

---

nginx-deploy-blue.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: nginx
  name: nginx-deploy-blue
spec:
  replicas: 1
  selector:
    matchLabels:
      run: nginx-blue
  template:
    metadata:
      labels:
        run: nginx-blue
    spec:
      volumes:
      - name: webdata
        emptyDir: {}
      initContainers:
      - name: web-content
        image: busybox
        volumeMounts:
        - name: webdata
          mountPath: "/webdata"
        command: ["/bin/sh", "-c", 'echo "<h1>I am <font color=blue>BLUE</font></h1>" > /webdata/index.html']
      containers:
      - image: nginx
        name: nginx
        volumeMounts:
        - name: webdata
          mountPath: "/usr/share/nginx/html"

Sau khi apply 3 file trên thì ra tạo nhanh service

Chúng ta đi qua 3 file ingress:

File đầu tiên thì cấu hình nginx rất bình thường:

ingress-resource-1.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-resource-1
spec:
  rules:
  - host: nginx.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-deploy-main
            port: 
              number: 80

File thứ 2 đặc biệt hơn là ingress sẽ route cho 3 trang web

ingress-resource-2.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-resource-2
spec:
  rules:
  - host: nginx.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-deploy-main
            port:
              number: 80
  - host: blue.nginx.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-deploy-blue
            port:
              number: 80
  - host: green.nginx.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-deploy-green
            port:
              number: 80

File thứ 3 ta sử dụng annotations để controller ingress nginx và đây là ví dụ sub path “/”

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
  name: ingress-resource-3
spec:
  rules:
  - host: nginx.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-deploy-main
            port:
              number: 80
      - path: /blue
        pathType: Prefix
        backend:
          service:
            name: nginx-deploy-blue
            port:
              number: 80
      - path: /green
        pathType: Prefix
        backend:
          service:
            name: nginx-deploy-green
            port:
              number: 80

Nếu bạn đã sử dụng nginx bạn sẽ thấy dễ hiểu:

Thêm một số rewriting mà các bạn muốn tham khảo:

https://kubernetes.github.io/ingress-nginx/examples/rewrite/