12.2.1、奇巧淫技

前提：在集群部署好Nginx Ingress

Redirect

redirect主要用于域名重定向，比如访问a.com被重定向到b.com。
如下我们配置访问ng.coolops.com重定向到www.baidu.com

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/permanent-redirect: "https://www.baidu.com"
spec:
  rules:
  - host: ng.coolops.cn 
    http:
      paths:
      - path:
        backend:
          serviceName: ng-svc
          servicePort: 80

然后浏览器访问ng.coolops.cn就会被重定向到https://www.baidu.com

PS E:\DEV\Go\src\code.rookieops.com\coolops> curl.exe -I http://ng.coolops.cn:30369
HTTP/1.1 301 Moved Permanently
Server: nginx/1.17.10
Date: Tue, 12 May 2020 09:06:29 GMT
Content-Type: text/html
Content-Length: 170
Connection: keep-alive
Location: https://www.baidu.com

Rewrite

rewrite主要用于地址重写，比如访问a.com/foo重写到a.com，访问a.com/foo/bbb重写到a.com/bbb。
比如下面例子：

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/rewrite-target: "/$1"
spec:
  rules:
  - host: ng.coolops.cn 
    http:
      paths:
      - path: /foo/?(.*)
        backend:
          serviceName: ng-svc
          servicePort: 80

匹配请求头

匹配请求头，主要用于根据请求头信息将用户请求转发到不同的应用，比如根据不同的客户端转发请求。
如下：

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/server-snippet: |
        set $agentflag 0;
        if ($http_user_agent ~* "(iPhone)" ){
          set $agentflag 1;
        }
        if ( $agentflag = 1 ) {
          return 301 http://iphone.coolops.cn:30369;
        }
spec:
  rules:
  - host: ng.coolops.cn 
    http:
      paths:
      - path:
        backend:
          serviceName: ng-svc
          servicePort: 80

然后再创建一个iphone.coolops.cn的ingress，我这里只是测试就随便定义了，如下：

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  rules:
  - host: iphone.coolops.cn 
    http:
      paths:
      - path: 
        backend:
          serviceName: ng-svc
          servicePort: 80

我现在以iPad访问，我们发现起没有被301重定向。

当我们使用iPhone访问的时候，可以发现起被301重定向了

认证访问

有些访问是需要认证访问的，比如dubbo-admin，我们在访问的时候会先叫你输入用户名和密码。ingress nginx也可以实现这种。
（1）、创建密码，我这里用http的命令工具来生成

[root@k8s-master ingress-nginx]# htpasswd -c auth joker
New password: 
Re-type new password: 
Adding password for user joker
[root@k8s-master ingress-nginx]# cat auth 
joker:$apr1$R.G4krs/$hh0mX8xe4A3lYKMjvlVs1/

（2）、创建secret

[root@k8s-master ingress-nginx]# kubectl create secret generic basic-auth --from-file=auth 
secret/basic-auth created

（3）、配置Ingress

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
spec:
  rules:
  - host: iphone.coolops.cn 
    http:
      paths:
      - path: 
        backend:
          serviceName: ng-svc
          servicePort: 80

黑白名单

在配置NG的时候可以用allow和deny来配置黑白名单，在ingress nginx上也可以设置黑白名单。
（1）、白名单
添加白名单的方式可以直接写annotation，也可以配置在ConfigMap中。
写在annotation中：

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/whitelist-source-range: 10.1.10.2
spec:
  rules:
  - host: iphone.coolops.cn 
    http:
      paths:
      - path: 
        backend:
          serviceName: ng-svc
          servicePort: 80

也可以写固定IP，也可以写网段。

配置到ConfigMap中：

apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.1.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.32.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
data:
  whitelist-source-range: 10.1.10.0/24

然后重新apply一下就OK

（2）、黑名单
黑名单就只能通过ConfigMap来配置了，配置如下：

apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.1.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.32.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
data:
  whitelist-source-range: 10.1.10.0/24
  block-cidrs: 10.1.10.100

速率限制

可以限制速率来降低后端压力，比如如下配置：

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/limit-rate: "100K"
    nginx.ingress.kubernetes.io/limit-whitelist: "10.1.10.100"
    nginx.ingress.kubernetes.io/limit-rps: "1"
    nginx.ingress.kubernetes.io/limit-rpm: "30"
spec:
  rules:
  - host: iphone.coolops.cn 
    http:
      paths:
      - path: 
        backend:
          serviceName: ng-svc
          servicePort: 80

其中：

• nginx.ingress.kubernetes.io/limit-rate：限制客户端每秒传输的字节数
• nginx.ingress.kubernetes.io/limit-whitelist：白名单中的IP不限速
• nginx.ingress.kubernetes.io/limit-rps：单个IP每秒的连接数
• nginx.ingress.kubernetes.io/limit-rpm：单个IP每分钟的连接数

更多请点这里。

灰度发布

Nginx Annotations 支持以下 4 种 Canary 规则：

• nginx.ingress.kubernetes.io/canary-by-header：基于 Request Header 的流量切分，适用于灰度发布以及 A/B 测试。当 Request Header 设置为 always时，请求将会被一直发送到 Canary 版本；当 Request Header 设置为 never时，请求不会被发送到 Canary 入口；对于任何其他 Header 值，将忽略 Header，并通过优先级将请求与其他金丝雀规则进行优先级的比较。
• nginx.ingress.kubernetes.io/canary-by-header-value：要匹配的 Request Header 的值，用于通知 Ingress 将请求路由到 Canary Ingress 中指定的服务。当 Request Header 设置为此值时，它将被路由到 Canary 入口。该规则允许用户自定义 Request Header 的值，必须与上一个 annotation (即：canary-by-header）一起使用。
• nginx.ingress.kubernetes.io/canary-weight：基于服务权重的流量切分，适用于蓝绿部署，权重范围 0 - 100 按百分比将请求路由到 Canary Ingress 中指定的服务。权重为 0 意味着该金丝雀规则不会向 Canary 入口的服务发送任何请求。权重为 100 意味着所有请求都将被发送到 Canary 入口。
• nginx.ingress.kubernetes.io/canary-by-cookie：基于 Cookie 的流量切分，适用于灰度发布与 A/B 测试。用于通知 Ingress 将请求路由到 Canary Ingress 中指定的服务的cookie。当 cookie 值设置为 always时，它将被路由到 Canary 入口；当 cookie 值设置为 never时，请求不会被发送到 Canary 入口；对于任何其他值，将忽略 cookie 并将请求与其他金丝雀规则进行优先级的比较。

定义两个版本的代码。
代码v1

package main
import (
    "github.com/gin-gonic/gin"
    "net/http"
)
func main(){
    g:=gin.Default()
    g.GET("/", func(c *gin.Context) {
        c.JSON(http.StatusOK,gin.H{
            "version": "v1",
            "data": "hello world",
        })
        })
    _ = g.Run("8080")
}

代码v2

package main
import (
    "github.com/gin-gonic/gin"
    "net/http"
)
func main(){
    g:=gin.Default()
    g.GET("/", func(c *gin.Context) {
        c.JSON(http.StatusOK,gin.H{
            "version": "v2",
            "data": "hello world,SB",
        })
        })
    _ = g.Run("8080")
}

然后制作镜像，这里我们正好可以练习下多阶段构建…
Dockerfile如下：

FROM golang AS build-env
ADD . /go/src/app
WORKDIR /go/src/app
RUN go get -u -v github.com/gin-gonic/gin
RUN govendor sync
RUN GOOS=linux GOARCH=386 go build -v -o /go/src/app/app-server-v1
FROM alpine
RUN ln -sf /usr/share/zoneinfo/Asia/Shanghai  /etc/localtime
COPY --from=build-env /go/src/app/app-server-v1 /usr/local/bin/app-server-v1
EXPOSE 8080
CMD [ "/usr/local/bin/app-server-v1" ]

构建镜像

docker build -t registry.cn-hangzhou.aliyuncs.com/rookieops/go-test:v1 .

上传镜像

docker push registry.cn-hangzhou.aliyuncs.com/rookieops/go-test:v1

v2版本相同操作

v1版本的deploy和svc

apiVersion: apps/v1 
kind: Deployment
metadata:
  name: app-server-v1
spec:
  selector:
    matchLabels:
      app: app-server-v1
  replicas: 2
  template:
    metadata:
      labels:
        app: app-server-v1
    spec:
      containers:
      - name: app-server-v1
        image: registry.cn-hangzhou.aliyuncs.com/rookieops/go-test:v1
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: app-server-v1-svc
spec:
  selector:
    app: app-server-v1
  ports:
  - name: http
    port: 8080

v2版本deploy和svc

apiVersion: apps/v1 
kind: Deployment
metadata:
  name: app-server-v2
spec:
  selector:
    matchLabels:
      app: app-server-v2
  replicas: 2
  template:
    metadata:
      labels:
        app: app-server-v2
    spec:
      containers:
      - name: app-server-v2
        image: registry.cn-hangzhou.aliyuncs.com/rookieops/go-test:v2
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: app-server-v2-svc
spec:
  selector:
    app: app-server-v2
  ports:
  - name: http
    port: 8080

运行两个版本进行测试：

[root@k8s-master ingress-nginx]# curl 10.103.133.234:8080
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl 10.101.125.220:8080
{"data":"hello SB","version":"v2"}

然后创建ingress。
（1）、正常版本（v1版本）

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  rules:
  - host: ng.coolops.cn
    http:
      paths:
      - path:
        backend:
          serviceName: app-server-v1
          servicePort: 8080

部署后访问

（2）、v2版本

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "10"
spec:
  rules:
  - host: ng.coolops.cn
    http:
      paths:
      - path:
        backend:
          serviceName: app-server-v2-svc
          servicePort: 8080

说明：

• nginx.ingress.kubernetes.io/canary: true 表示开启canary
• nginx.ingress.kubernetes.io/canary-weight: 10 表示权重为10，也就是v1:v2大致为9:1

然后部署后进行测试：

[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"} 
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello world","version":"v1"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello SB","version":"v2"}
[root@k8s-master ingress-nginx]# curl http://ng.coolops.cn:30369
{"data":"hello SB","version":"v2"}

可以看到上述的这些操作基本都用到annotation，更多的可以点击官方文档。