kubernetes（3）

目录

service微服务

ipvs模式

clusterip

headless

nodeport

loadbalancer

metallb

nodeport默认端口

externalname

ingress-nginx

部署

基于路径访问

基于域名访问

TLS加密

auth认证

rewrite重定向

canary金丝雀发布

基于header灰度

基于权重灰度

业务域拆分

---

service微服务

创建测试示例

[root@k8s2 service]# vim myapp.yml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  replicas: 6
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - image: myapp:v1
        name: myapp

---

apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp
  type: ClusterIP            //ClusterIP是Kubernetes Service的一种类型。它为同一个Kubernetes集群中的其他Pod提供了访问Service的IP地址。这个IP地址和Service是虚拟的, 不对外暴露，只能在集群内部使用。

ClusterIP Service类型默认使用iptables调度。iptables负责将Service的ClusterIP地址映射到后端Pod的IP地址和端口上，处理请求的负载均衡和高可用性

ipvs模式

修改proxy配置

[root@k8s2 pod]# kubectl -n kube-system edit  cm kube-proxy
...
mode: "ipvs"        //IPVS是一种高性能负载均衡技术，与iptables相比具有更高的性能和更丰富的负载均衡策略

重启pod

[root@k8s2 pod]# kubectl -n kube-system get pod|grep kube-proxy | awk '{system("kubectl -n kube-system delete pod "$1"")}'

切换ipvs模式后，kube-proxy会在宿主机上添加一个虚拟网卡：kube-ipvs0，并分配service IP

clusterip

clusterip模式只能在集群内访问

[root@k8s2 service]# vim myapp.yml
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp
  type: ClusterIP

service创建后集群DNS提供解析

headless

[root@k8s2 service]# vim myapp.yml
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp
  type: ClusterIP
  clusterIP: None            //当 ClusterIP 设置为 None 时，Kubernetes 不会为该 Service 分配一个 Cluster IP，并且 DNS 请求的返回值将不会是 Service 的虚拟 IP，而是真实的 Pod IP。

[root@k8s2 service]# kubectl delete svc myapp
[root@k8s2 service]# kubectl apply -f myapp.yml

headless模式不分配vip

headless通过svc名称访问，由集群内dns提供解析

集群内直接使用service名称访问

nodeport

[root@k8s2 service]# vim myapp.yml
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp
  type: NodePort        //NodePort 类型会在每个 Node 上监听一个静态端口，并将请求转发到后端 Pod 的 Cluster IP。这种类型的 Service 可以通过 : 的方式访问到后端 Pod。
使用 NodePort 类型的 Service 可以让外部用户通过 Node IP 和 Node 端口来访问到集群内部的服务。

[root@k8s2 service]# kubectl apply -f myapp.yml
[root@k8s2 service]# kubectl get svc

nodeport在集群节点上绑定端口，一个端口对应一个服务

loadbalancer

[root@k8s2 service]# vim myapp.yml
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp
  type: LoadBalancer
//使用 LoadBalancer 类型的 Service 可以在集群外部暴露一个负载均衡器，让外部用户能够轻松访问到集群内部的服务。
使用 LoadBalancer 类型的 Service 必须在 Kubernetes 集群部署在某些支持云服务商的基础设施上，否则该类型的 Service 无法正常工作。

LoadBalancer模式适用云平台，裸金属环境需要安装metallb提供支持

metallb

官网：MetalLB, bare metal load-balancer for Kubernetes

[root@k8s2 service]# kubectl edit configmap -n kube-system kube-proxy
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: "ipvs"
ipvs:
  strictARP: true         //启用 Kubernetes Service 的 strictARP 选项可以防止 ARP 欺骗攻击，提高网络安全性

[root@k8s2 service]# kubectl -n kube-system get pod|grep kube-proxy | awk '{system("kubectl -n kube-system delete pod "$1"")}'

 

下载部署文件

[root@k8s2 metallb]# wget https://raw.githubusercontent.com/metallb/metallb/v0.13.11/config/manifests/metallb-native.yaml

修改文件中镜像地址,与harbor仓库路径保持一致

上传镜像到harbor

部署服务

[root@k8s2 metallb]# kubectl apply -f metallb-native.yaml
[root@k8s2 metallb]# kubectl -n metallb-system get pod

配置分段地址段

[root@k8s2 metallb]# vim config.yaml
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: first-pool
  namespace: metallb-system
spec:
  addresses:
  - 192.168.81.100-192.168.81.200			//修改为自己本地地址段

---
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: example
  namespace: metallb-system
spec:
  ipAddressPools:
  - first-pool

通过分配地址从集群外访问服务

nodeport默认端口

[root@k8s2 service]# vim myapp.yml

apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
    nodePort: 33333
  selector:
    app: myapp
  type: NodePort

nodeport默认端口是30000-32767，超出会报错

添加如下参数，端口范围可以自定义

[root@k8s2 service]# vim /etc/kubernetes/manifests/kube-apiserver.yaml
--service-node-port- range=30000-50000

修改后api-server会自动重启，等apiserver正常启动后才能操作集群

externalname

[root@k8s2 service]# vim externalname.yaml
apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type:  ExternalName            //ExternalName 类型的 Service 不会创建任何 ClusterIP、NodePort、LoadBalancer 类型的 Endpoint，在集群内部也不会创建任何 Pod，它会将 Service 名称与一个外部的 DNS 名称（或者 IP 地址）关联起来
  externalName: www.westos.org     //当集群内部的应用程序访问该 Service 时，将会通过集群的 DNS 解析服务解析该 Service 名称，返回关联的 www.westos.org 的 DNS 名称

ingress-nginx

ingress-nginx 是一个 Kubernetes 上的 Ingress 控制器，它提供了负载均衡、SSL/TLS 等功能，可以将外部访问 Kubernetes 集群内部的服务

部署

官网：https://kubernetes.github.io/ingress-nginx/deploy/#bare-metal-clusters

下载部署文件，上传镜像到harbor

修改3个镜像路径

修改为LoadBalancer方式

[root@k8s2 ingress]# kubectl -n ingress-nginx edit  svc ingress-nginx-controller

创建ingress策略

[root@k8s2 ingress]# vim ingress.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: minimal-ingress
spec:
  ingressClassName: nginx
  rules:
  - http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp
            port:
              number: 80

基于路径访问

创建svc

[root@k8s2 ingress]# vim myapp-v1.yml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp-v1
  name: myapp-v1
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp-v1
  template:
    metadata:
      labels:
        app: myapp-v1
    spec:
      containers:
      - image: myapp:v1
        name: myapp-v1

---

apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp-v1
  name: myapp-v1
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp-v1
  type: ClusterIP

[root@k8s2 ingress]# vim myapp-v2.yml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp-v2
  name: myapp-v2
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp-v2
  template:
    metadata:
      labels:
        app: myapp-v2
    spec:
      containers:
      - image: myapp:v2
        name: myapp-v2

---

apiVersion: v1
kind: Service
metadata:
  labels:
    app: myapp-v2
  name: myapp-v2
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: myapp-v2
  type: ClusterIP

创建ingress

[root@k8s2 ingress]# vim ingress1.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: minimal-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - path: /v1
        pathType: Prefix
        backend:
          service:
            name: myapp-v1
            port:
              number: 80

      - path: /v2
        pathType: Prefix
        backend:
          service:
            name: myapp-v2
            port:
              number: 80

测试

基于域名访问

[root@k8s2 ingress]# vim ingress2.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: minimal-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp1.westos.org
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-v1
            port:
              number: 80

  - host: myapp2.westos.org
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-v2
            port:
              number: 80

TLS加密

创建证书

[root@k8s2 ingress]# openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/CN=nginxsvc/O=nginxsvc"
[root@k8s2 ingress]# kubectl create secret tls tls-secret --key tls.key --cert tls.crt

[root@k8s2 ingress]# vim ingress3.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-tls
spec:
  tls:
    - hosts:
      - myapp.westos.org
      secretName: tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-v1
            port:
              number: 80

auth认证

创建认证文件

[root@k8s2 ingress]# yum install -y httpd-tools
[root@k8s2 ingress]# htpasswd -c auth shx
[root@k8s2 ingress]# kubectl create secret generic basic-auth --from-file=auth

[root@k8s2 ingress]# vim ingress3.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-tls
  annotations:
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
    nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required - shx'
spec:
  tls:
    - hosts:
      - myapp.westos.org
      secretName: tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-v1
            port:
              number: 80

rewrite重定向

示例一：

[root@k8s2 ingress]# vim ingress3.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-tls
  annotations:
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
    nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required - shx'
    nginx.ingress.kubernetes.io/app-root: /hostname.html
spec:
  tls:
    - hosts:
      - myapp.westos.org
      secretName: tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-v1
            port:
              number: 80

示例二：

[root@k8s2 ingress]# vim ingress3.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-tls
  annotations:
    nginx.ingress.kubernetes.io/auth-type: basic
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
    nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required - shx'
    #nginx.ingress.kubernetes.io/app-root: /hostname.html
    nginx.ingress.kubernetes.io/use-regex: "true"
    nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
  tls:
    - hosts:
      - myapp.westos.org
      secretName: tls-secret
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-v1
            port:
              number: 80
      - path: /westos(/|$)(.*)
        pathType: ImplementationSpecific
        backend:
          service:
            name: myapp-v1
            port:
              number: 80

canary金丝雀发布

基于header灰度

[root@k8s2 ingress]# vim ingress4.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myapp-v1-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - pathType: Prefix
        path: /
        backend:
          service:
            name: myapp-v1
            port:
              number: 80

[root@k8s2 ingress]# vim ingress5.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-by-header: stage
    nginx.ingress.kubernetes.io/canary-by-header-value: gray
  name: myapp-v2-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - pathType: Prefix
        path: /
        backend:
          service:
            name: myapp-v2
            port:
              number: 80

测试

基于权重灰度

[root@k8s2 ingress]# vim ingress5.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/canary: "true"
    #nginx.ingress.kubernetes.io/canary-by-header: stage
    #nginx.ingress.kubernetes.io/canary-by-header-value: gray
    nginx.ingress.kubernetes.io/canary-weight: "50"
    nginx.ingress.kubernetes.io/canary-weight-total: "100"

  name: myapp-v2-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - pathType: Prefix
        path: /
        backend:
          service:
            name: myapp-v2
            port:
              number: 80

测试

[root@k8s1 ~]# vim ingress.sh
#!/bin/bash

v1=0
v2=0

for (( i=0; i<100; i++))
do
    response=`curl -s myapp.westos.org |grep -c v1`

    v1=`expr $v1 + $response`
    v2=`expr $v2 + 1 - $response`

done

echo "v1:$v1, v2:$v2"

业务域拆分

[root@k8s2 ingress]# vim ingress6.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$1
  name: rewrite-ingress
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.westos.org
    http:
      paths:
      - path: /user/(.*)
        pathType: Prefix
        backend:
          service:
            name: myapp-v1
            port:
              number: 80
      - path: /order/(.*)
        pathType: Prefix
        backend:
          service:
            name: myapp-v2
            port:
              number: 80

测试