四、Pod控制器详解

一、控制器介绍

controller用于控制pod，生产环境中都是使用控制器控制pod的。

1.1控制器的分类

  • ReplicaSet 副本集,控制pod扩容，裁减
  • Deployments 部署控制器，控制pod升级,回退，该控制器包含ReplicaSet
  • StatefulSets 部署有状态的pod应用
  • DaemonSet 守护进程的集合，运行在所有集群节点(包括master), 比如使用Filebeat，node_exporter（普罗米修士在客户端收集日志的工具）
  • Jobs 一次性的任务
  • Cronjob 周期性的任务

补充：ReplicationController也叫RC控制器，相当于ReplicaSet的老版本,现在不建议使用，现在使用Deployments加ReplicaSet替代RC，Deployments中是包含了ReplicaSet控制器的

1.2 有状态应用跟无状态应用

无状态应用（Stateless Application）是指应用不会在会话中保存下次会话所需要的客户端数据。每一个会话都像首次执行一样，不会依赖之前的数据进行响应；

举一个简单案例，无状态的服务器程序，就像web服务这样，每次HTTP请求和以前都没有啥关系，只是获取目标URI资源。得到目标内容之后，这次连接就会断开，没有任何痕迹。

有状态的应用（Stateful Application）是指应用会在会话中保存客户端的数据，并在客户端下一次的请求中来使用那些数据。

举一个简单案例，有状态的应用就指的是使用用户名密码登录的web服务器，需要使用COOKIE记录你的登录状态，服务端在响应客户端的请求的时候，会向客户端推送一个COOKIE，这个COOKIE记录服务端上面的一些信息。客户端在后续的请求中，可以携带这个COOKIE，这样访问该网站就不用每次都要输入账号密码了。

二、Deployment

2.1 Deployment简介

Replicaset控制器的功能:
控制Pod副本数量实现Pod的扩容和缩容。

Deployment控制器的功能:
Deployment集成了上线部署、滚动升级、创建副本、回滚等功能
Deployment里包含并使用了ReplicaSet控制器
Deployment用于部署无状态应用，适用于web微服务

2.2 创建Deployment

1.查看帮助

kubectl create -h

查看deployment帮助

#查看deployment帮助
kubectl explain deployment

2.使用命令创建deployment

1.创建一个名为nginx的deployment

#模拟创建一个deployment，不是真正的创建
kubectl create deployment nginx --image=nginx:1.15-alpine --port=80 --replicas=2 --dry-run=client

#上一条命令没报错，我们实际创建一个
kubectl create deployment nginx --image=nginx:1.15-alpine --port=80 --replicas=2

说明:

  • --port=80 相当于docker里的暴露端口
  • --replicas=2 指定副本数,默认为1
  • --dry-run=client为测试模式,相当于不是真的跑,只是先模拟测试一下

2.验证

kubectl get deployment
kubectl get pod -o wide

此时nginx是deployment控制器名，replicas副本数为2，也就是说有两个pod，pod名是nginx-6d9d558bb6-xxxxx，每个pod中只有一个容器，

3.查看deployment和pod详情

kubectl describe deployment nginx
kubectl describe pod nginx-6d9d558bb6-xxxxx

4.删除deployment

kubectl delete deployment nginx

3.YAML文件创建deployment

可以将前面创建的控制器导出为yaml文件

kubectl get deployment nginx -o yaml > deployment.yml

1, 准备YAML文件

Deployment控制器中包含了副本集，副本集在spec中定义

[root@k8s-master01 ~]# vim nginx-deployment.yml
apiVersion: apps/v1  #版本信息使用kubectl explain deployment查看
kind: Deployment
metadata:
  name: nginx # deployment控制器名
  labels:
    app: nginx-dep #deployment的标签名
    
# deployment里使用了副本集  
spec:               
  replicas: 2                   
  selector:
    matchLabels:
      app: nginx-dep  #注意：这里是关联pod标签为nginx-dep的pod
      
  template:                    # 代表pod的配置模板
    metadata:
      name: nginx               #这是pod名，随便写
      labels:
        app: nginx-dep         # 注意：这里指pod的标签，要跟matchLabels里的一致，他们是相关联的
    spec:
      containers:               
      - name: nginx              #容器名随便写，多个容器不能重名
        image: nginx:1.15-alpine
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

这里需要注意replicas定义的matchLabels名要跟template里定义的pod的标签名一致，这样他们才能关联起来

2, 应用YAML文件创建deployment

 kubectl apply -f nginx-deployment.yml

3, 查看验证

 kubectl get deployment
 kubectl get rs
 kubectl get pods

image-20211118181100950

补充：YAML单独创建replicaset

注意replicas必须跟template写在一起。

1, 编写YAML文件

[root@k8s-master01 ~]# vim replicaset.yml
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: nginx-rs  #ReplicaSet控制器名
  namespace: default
spec:                   
  replicas: 2            # 副本数
  selector:              # 标签选择器,对应下面pod的标签
    matchLabels:
      app: nginx         # 匹配的label
  template:
    metadata:
      name: nginx-pod      
      labels:           
        app: nginx #对应上面定义的标签选择器selector里面的名字
    spec:               
       containers: 
       - name: nginx  
         image: nginx:1.15-alpine
         ports:
         - name: http
           containerPort: 80

这里要注意的是selector标签选择器指定的标签名要跟template标签的名字对应，他们是相关联的

2, 应用YAML文件

kubectl apply -f replicaset.yml

3, 验证

kubectl get rs
kubectl get pods
kubectl get deployment

找不到deployment，说明单独创建的rs并没有创建deployment

image-20211119105407908

2.3 删除deployment

1.删除deployment

使用如下命令删除deployment，那么里面的rs跟pod也会被自动删除

kubectl delete deployment nginx-deployment
kubectl delete -f nginx-deployment.yml

2.删除deployment中的pod

删之前想一想之前提到的副本控制器replicaset的作用

1, 删除nginx的pod

kubectl get pod
kubectl delete pod nginx-7d9b8757cf-xxxx

2, 再次查看，发现又重新启动了一个pod，pod的IP也发生了变化

kubectl get pods -o wide

  • 因为在deployment控制器中定义了副本分片，如果pod数量不满足副本分片的数量，就会启动或缩减pod数量直到满足副本分片数。

  • pod的IP不是固定的，一旦pod因为故障导致重启，IP就会发生变化；

  • 如果想固定访问某个IP就能访问到对应的pod的话，就需要以后会提到的service了，service就相当于是一个VIP。

2.4 pod版本升级

查看帮助

kubectl set image -h

1, 升级前验证nginx版本

kubectl get pod
kubectl describe pod nginx-6bb55459d-j7bbg |grep Image:
kubectl exec nginx-6bb55459d-j7bbg -- nginx -v

2, 升级为1.16版

#先查看pod里的容器名
kubectl get pods nginx-6bb55459d-j7bbg -o jsonpath={.spec.containers[*].name}

#升级pod镜像版本
kubectl set image deployment nginx nginx=nginx:1.16-alpine --record

说明:

  • deployment nginx 代表名为nginx的deployment

  • nginx=nginx:1.16-alpine 前面的nginx为容器名

  • --record 表示会记录信息，如果不加后面回退显示版本为None（这个后面会说明）

查看容器名的其他方式:

  • kubectl describe pod <pod名>
  • kubectl edit deployment <deployment名>
  • kubectl get deployment <deployment名> -o yaml

3, 验证

kubectl get pod #此时的pod名已发生改变
kubectl describe pod nginx-684c89cf5c-2q9gq |grep Image:
kubectl exec nginx-684c89cf5c-2q9gq -- nginx -v

#查看更新状态
kubectl rollout status deployment nginx

2.5 pod版本回退

1, 查看版本历史信息

还记得版本升级用的--record选项么，对，这个就是记录你升级的版本信息的

kubectl rollout history deployment nginx

如果没有加--record，就会显示为，所以做版本更新一定要加上--record

2, 定义要回退的版本

#--revision=1，这里的1指的前面的版本序号，会显示这个版本的信息
kubectl rollout history deployment nginx --revision=1

image-20211119163005509

3, 执行回退（执行后才是真的回退)

kubectl rollout undo deployment nginx --to-revision=1

4, 验证

kubectl rollout history deployment nginx
kubectl get pods
kubectl describe pod nginx-6bb55459d-6nfgr |grep Image:

2.6 副本扩容

查看帮助

 kubectl scale -h

1, 扩容为2个副本

kubectl scale deployment nginx --replicas=2

2, 查看

kubectl get pods -o wide

3, 继续扩容

kubectl scale deployment nginx --replicas=4
kubectl get pods -o wide

2.7 副本裁减

1, 指定副本数为1进行裁减

 kubectl scale deployment nginx --replicas=1

2, 查看验证

kubectl get pods -o wide
kubectl get pods | wc -l #统计pod个数

三、DaemonSet

3.1 DaemonSet简介

  • DaemonSet能够让所有（或者特定）的节点运行同一个pod。当新节点加入到K8S集群中，pod会被（DaemonSet）自动调度到该节点上运行，当节点从K8S集群中被移除，被DaemonSet调度的pod会被移除

  • 如果删除DaemonSet，所有跟这个DaemonSet相关的pods都会被删除。

  • 如果一个DaemonSet的Pod被杀死、停止、或者崩溃，那么DaemonSet将会重新创建一个新的副本在这台计算节点上。

  • DaemonSet一般应用于日志收集、监控采集、分布式存储守护进程等

3.2 创建DaemonSet

1, 编写YAML文件

[root@k8s-master01 ~]# vim nginx-daemonset.yml
apiVersion: apps/v1
kind: DaemonSet
metadata:
   name: nginx-daemonset             
spec:
   selector:
      matchLabels:  #DaemonSet的标签选择器，要跟下面pod的标签对应
         name: nginx-test 
   template:
      metadata:
         labels:
            name: nginx-test #pod的标签，跟选择器必须一致
      spec:
         tolerations:    # tolerations代表容忍，容许
         - key: node-role.kubernetes.io/k8s-master01  # 能容忍的污点key
           effect: NoSchedule   # kubectl explain pod.spec.tolerations查看(能容忍的污点effect)
         containers:
         - name: nginx
           image: nginx:1.15-alpine
           imagePullPolicy: IfNotPresent
           resources:      #资源限制
              limits:
                 memory: 100Mi
              requests:
                  memory: 100Mi

2, apply应用YAML文件

 kubectl apply -f nginx-daemonset.yml

3, 验证

kubectl get daemonset
kubectl get pods |grep nginx-daemonset

image-20211119164204076

可以看到daemonset在每个节点都创建了pod

四、Job

4.1 job简介

  • 对于ReplicaSet而言，它希望pod保持预期数目、持久运行下去，除非用户明确删除，否则这些对象一直存在，它们针对的是耐久性任务，如web服务等。

  • 对于非耐久性任务，比如压缩文件，任务完成后，pod需要结束运行，不需要pod继续保持在系统中，这个时候就要用到Job。

  • Job负责批量处理短暂的一次性任务 (short lived one-offff tasks)，即仅执行一次的任务，它保证批处理任务的一个或多个Pod成功结束。

4.2 案例1: 计算圆周率2000位

[root@k8s-master01 ~]# vim job.yml
apiVersion: batch/v1
kind: Job
metadata:
   name: pi          # job名
spec:
   template:
      metadata:
         name: pi      # pod名
      spec:
         containers:
         - name: pi    # 容器名
           image: perl # 此镜像有800多M,可提前导入到所有节点,也可能指定导入到某一节点然后指定调度到此节点
           imagePullPolicy: IfNotPresent
           command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
         restartPolicy: Never    # 执行完后不再重启

2, 应用YAML文件创建job

kubectl apply -f job.yml

3, 验证

kubectl get jobs
kubectl get pods
kubectl logs pi--1-lb75l #查看计算结果，计算结果在日志中
kubectl logs pi--1-lb75l | wc -c #统计一共多少位
kubectl logs pi--1-lb75l | wc -L

image-20211119170311431

STATUS显示为Completed表示计算能完成，此时才能查看计算结果

4.3 案例2: 创建固定次数job

1, 编写YAML文件

[root@k8s-master01 ~]# vim job2.yml
apiVersion: batch/v1
kind: Job
metadata:
   name: busybox-job
spec:
   completions: 10                                                   
         # 执行job的次数
   parallelism: 1                                                     
        # 执行job的并发数，这表示一次做一个，一共做十次
   template:
      metadata:
         name: busybox-job-pod
      spec:
         containers:
         - name: busybox
           image: busybox
           imagePullPolicy: IfNotPresent
           command: ["echo", "hello"]
         restartPolicy: Never

2, 应用YAML文件创建job

 kubectl apply -f job2.yml

3, 验证

 kubectl get job
 kubectl get pods | grep busybox
 kubectl logs busybox-job--1-4w6mz

可以看到启动了10个pod来输出hello

五、cronjob

类似于Linux系统的crontab，在指定的时间周期运行相关的任务，类似于计划任务

1, 编写YAML文件

[root@k8s-master01 ~]# vim cronjob.yml
apiVersion: batch/v1
kind: CronJob
metadata:
   name: cronjob1
spec:
   schedule: "* * * * *"     # 分时日月周，全星号表示每分钟都做
   jobTemplate:
      spec:
         template:
            spec:
               containers:
               - name: hello
                 image: busybox
                 args:
                 - /bin/sh
                 - -c
                 - date; echo hello kubernetes
                 imagePullPolicy: IfNotPresent
               restartPolicy: OnFailure #失败了才重启

2, 应用YAML文件创建cronjob

kubectl apply -f cronjob.yml

3, 查看验证

kubectl get cronjob
kubectl get pods | grep cron #因为是周期性的，所以每分钟就会有一个完成状态的pod
#查看输出结果
kubectl logs cronjob1-27288555--1-2bzzg

周期性的只会保留最近的3个pod

六、Ingress

6.1 Ingress简介

前面提到的Service实现的是四层负载均衡，使用的是IP跟端口的形式，而Ingress使用的是七层负载均衡，可以使用域名进行负载均衡。

关于介绍看这篇，废话不多说我们直接安装，这里介绍两种安装方式，一种是yaml文件部署，一种是使用helm包管理工具。

重点来了，我是用的是二进制安装的k8s，版本是v1.22.2，所以Ingress-nginx的版本尽可能用最新的，不然会报错，详见版本对照表。

6.2 yaml部署Ingress

1.创建ingress-control.yaml文件

点击查看代码 
[root@k8s-master01 ~]# cat ingress-control.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx

---
# Source: ingress-nginx/templates/controller-serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
automountServiceAccountToken: true
---
# Source: ingress-nginx/templates/controller-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
data:
---
# Source: ingress-nginx/templates/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - networking.k8s.io
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - networking.k8s.io
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
---
# Source: ingress-nginx/templates/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - configmaps
      - pods
      - secrets
      - endpoints
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - networking.k8s.io
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - networking.k8s.io
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - configmaps
    resourceNames:
      - ingress-controller-leader
    verbs:
      - get
      - update
  - apiGroups:
      - ''
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
---
# Source: ingress-nginx/templates/controller-rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-service-webhook.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller-admission
  namespace: ingress-nginx
spec:
  type: ClusterIP
  ports:
    - name: https-webhook
      port: 443
      targetPort: webhook
      appProtocol: https
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-deployment.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/instance: ingress-nginx
      app.kubernetes.io/component: controller
  revisionHistoryLimit: 10
  minReadySeconds: 0
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/component: controller
    spec:
      hostNetwork: true
      dnsPolicy: ClusterFirst
      containers:
        - name: controller
          image: registry.cn-beijing.aliyuncs.com/kole_chang/controller:v1.0.0
          imagePullPolicy: IfNotPresent
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown
          args:
            - /nginx-ingress-controller
            - --election-id=ingress-controller-leader
            - --controller-class=k8s.io/ingress-nginx
            - --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
            - --validating-webhook=:8443
            - --validating-webhook-certificate=/usr/local/certificates/cert
            - --validating-webhook-key=/usr/local/certificates/key
            - --watch-ingress-without-class=true
          securityContext:
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            runAsUser: 101
            allowPrivilegeEscalation: true
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
            - name: LD_PRELOAD
              value: /usr/local/lib/libmimalloc.so
          livenessProbe:
            failureThreshold: 5
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 1
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 1
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
            - name: https
              containerPort: 443
              protocol: TCP
            - name: webhook
              containerPort: 8443
              protocol: TCP
          volumeMounts:
            - name: webhook-cert
              mountPath: /usr/local/certificates/
              readOnly: true
          resources:
            requests:
              cpu: 100m
              memory: 90Mi
      nodeSelector:
        kubernetes.io/os: linux
      serviceAccountName: ingress-nginx
      terminationGracePeriodSeconds: 300
      volumes:
        - name: webhook-cert
          secret:
            secretName: ingress-nginx-admission
---
# Source: ingress-nginx/templates/controller-ingressclass.yaml
# We don't support namespaced ingressClass yet
# So a ClusterRole and a ClusterRoleBinding is required
apiVersion: networking.k8s.io/v1
kind: IngressClass
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: nginx
  namespace: ingress-nginx
spec:
  controller: k8s.io/ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/validating-webhook.yaml
# before changing this value, check the required kubernetes version
# https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#prerequisites
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  name: ingress-nginx-admission
webhooks:
  - name: validate.nginx.ingress.kubernetes.io
    matchPolicy: Equivalent
    rules:
      - apiGroups:
          - networking.k8s.io
        apiVersions:
          - v1
        operations:
          - CREATE
          - UPDATE
        resources:
          - ingresses
    failurePolicy: Fail
    sideEffects: None
    admissionReviewVersions:
      - v1
    clientConfig:
      service:
        namespace: ingress-nginx
        name: ingress-nginx-controller-admission
        path: /networking/v1/ingresses
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: ingress-nginx-admission
  namespace: ingress-nginx
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
rules:
  - apiGroups:
      - admissionregistration.k8s.io
    resources:
      - validatingwebhookconfigurations
    verbs:
      - get
      - update
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: ingress-nginx-admission
  namespace: ingress-nginx
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
rules:
  - apiGroups:
      - ''
    resources:
      - secrets
    verbs:
      - get
      - create
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: ingress-nginx-admission
  namespace: ingress-nginx
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-createSecret.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-create
  namespace: ingress-nginx
  annotations:
    helm.sh/hook: pre-install,pre-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
spec:
  template:
    metadata:
      name: ingress-nginx-admission-create
      labels:
        helm.sh/chart: ingress-nginx-4.0.1
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 1.0.0
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: create
          image: registry.cn-beijing.aliyuncs.com/kole_chang/kube-webhook-certgen:v1.0
          imagePullPolicy: IfNotPresent
          args:
            - create
            - --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc
            - --namespace=$(POD_NAMESPACE)
            - --secret-name=ingress-nginx-admission
          env:
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      nodeSelector:
        kubernetes.io/os: linux
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-patchWebhook.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-patch
  namespace: ingress-nginx
  annotations:
    helm.sh/hook: post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-4.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 1.0.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
spec:
  template:
    metadata:
      name: ingress-nginx-admission-patch
      labels:
        helm.sh/chart: ingress-nginx-4.0.1
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 1.0.0
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: patch
          image: registry.cn-beijing.aliyuncs.com/kole_chang/kube-webhook-certgen:v1.0
          imagePullPolicy: IfNotPresent
          args:
            - patch
            - --webhook-name=ingress-nginx-admission
            - --namespace=$(POD_NAMESPACE)
            - --patch-mutating=false
            - --secret-name=ingress-nginx-admission
            - --patch-failure-policy=Fail
          env:
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      nodeSelector:
        kubernetes.io/os: linux
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000

这里涉及到使用两个镜像，因为我的k8s是v1.22.2版本的，镜像最好也用v1.0以上版本不然会报错，另外镜像已经在阿里云上了，国内可以访问到

image-20211125150637235

2.应用yaml文件

kubectl apply -f ingress-control.yaml

3.查看

kubectl get pod -n ingress-nginx

image-20211124212811610

状态为Completed的两个pod是job控制器部署的，用于检查配置环境的，如图所示是部署成功的状态

参考文章：yaml部署Ingress

6.3 helm部署Ingress

helm是k8s的包管理器，好了开始安装Ingress

官方下载Helm

1.解压

tar -zxvf helm-v3.7.1-linux-amd64.tar.gz
mv linux-amd64/helm /usr/local/bin/helm

2.下载Ingress包

#添加ingress-ninx仓库
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx

#查看添加的仓库
helm repo list

#搜索ingress-nginx版本，直接安装最新版
helm search hub ingress-nginx
helm search repo ingress-nginx

#前面是仓库的名称，后面是包名
helm pull ingress-nginx/ingress-nginx

#解压下载下来的tgz包
tar xf ingress-nginx-4.0.10.tgz
cd ingress-nginx

#这里要修改几个地方
vim values.yam

①修改镜像地址

该values.yam会用到3个镜像，如果k8s是v1.22.2版本的，那么镜像版本一定要用v1.0及其以上的，修改这3个镜像地址为国内能访问的地址

在13、14行，18行，注释掉19行digest校验

registry: registry.cn-beijing.aliyuncs.com
image: kole_chang/controller

image-20211125152235545

在596、597、601行，注释掉602行digest校验

registry: registry.cn-beijing.aliyuncs.com
image: kole_chang/kube-webhook-certgen

image-20211125152334582

在721、722、726行，修改为如下图所示

registry: mirrorgooglecontainers
image: defaultbackend-amd64

image-20211125152548453

②修改参数

58行，dns策略改为ClusterFirstWithHostNet

dnsPolicy: ClusterFirstWithHostNet

81行，修改为主机网络模式

hostNetwork: true

183行，设置为守护进程集模式，这个就不用我多说了吧

kind: DaemonSet

新增283行，设置标签，表示使用ingress标签值为true的节点进行安装Ingress，注意格式要跟上一行对齐

ingress: "true"

483行，改为ClusterIP类型

type: ClusterIP

3.安装Ingress

#创建命名空间
kubectl create ns ingress-nginx

#给master01添加标签，让他安装ingress
kubectl label node k8s-master01 ingress=true
kubectl get nodes -L ingress

#安装
helm install ingress-nginx -n ingress-nginx .

#查看
kubectl get pod -n ingress-nginx
helm list -a -ningress-nginx


#报错查看
kubectl describe pod -n ingress-nginx ingress-nginx-admission-patch--1-6zvvt
kubectl logs -n ingress-nginx ingress-nginx-admission-patch--1-6zvvt

#删除helm包
helm delete ingress-nginx -n ingress-nginx

因为我只在master01上打了标签，所以ingress-nginx只在master01上安装了

image-20211125154628342

安装成功如下图所示

image-20211125151936387

参考资料：

Helm官方文档

Ingress官方文档

腾讯课堂

6.4 Ingress扩容缩容

前面yaml配置文件中写到Ingress会安装到标签ingress值为true的节点上，那么我们修改节点标签即可完成扩容

kubectl label node k8s-node01 ingress=true
kubectl get pod -n ingress-nginx -owide

缩容，删除该标签即可

kubectl label node k8s-master01 ingress-

6.5 部署单域名Ingress

Ingress-nginx原理上还是使用的Nginx来实现负载均衡的，所以会在其部署的节点上开启80端口用于Nginx服务

#因为配置使用的是宿主机模式，所以会使用宿主机80端口用于nginx服务
netstat -lntp | grep 80

image-20211125160630474

1.部署一个ingress

新版本的ingress格式跟旧版本的不一致，要看ingress-nginx的版本

ingress必须跟关联的Service在同一命名空间下。

[root@k8s-master01 ~]# vim ingress-tz.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-tz
  annotations:
    # use the shared ingress-nginx
    kubernetes.io/ingress.class: "nginx" #集群中可能使用了不止一种ingress，这里指定使用nginx的ingress，在value.yaml第98行与之对应
spec:
  rules: 
  - host: tzlinux.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-dep  #这里写要绑定的service服务名
            port: 
              number: 8000   #Service暴露的端口

有时候复制粘贴到vim编辑器中，格式会乱，这时在vim编辑器中使用:set paste即可

2.应用yaml文件

kubectl apply -f ingress-tz.yaml
kubectl get ingress

3.修改win主机hosts文件

10.154.0.112是我安装了Ingress-nginx的那台k8s-node01节点，这里要注意，只有安装了Ingress-nginx的节点才可以使用负载均衡

image-20211125162417029

4.访问tzlinux.com

image-20211125162726369

进入ingress的pod查看会发现我们写的ingress-tz.yaml文件已经解析为nginx.conf的配置了

kubectl exec -it ingress-nginx-controller-rmcfn -n ingress-nginx -- sh
grep "tzlinux.com" nginx.conf -A 20 #查看后20行

6.6 部署多域名Ingress

1.编写yaml文件

[root@k8s-master01 ~]# vim ingress-mulDomain.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-tz
  annotations:
    # use the shared ingress-nginx
    kubernetes.io/ingress.class: "nginx" #集群中可能使用了不止一种ingress，这里指定使用nginx的ingress，在value.yaml第98行与之对应
spec:
  rules: 
  - host: docker.tzlinux.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-dep  #这里写要绑定的service服务名
            port: 
              number: 8000   #Service暴露的端口
  - host: k8s.tzlinux.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx-svc  #这里写要绑定的service服务名
            port: 
              number: 8000   #Service暴露的端口

2.应用yaml文件

kubectl apply -f ingress-mulDomain.yaml

#如果修改了yaml文件可以使用来更新
kubectl replace -f ingress-mulDomain.yaml

3.修改Hosts文件

image-20211125235042932

4.使用浏览器访问

http://docker.tzlinux.com

http://k8s.tzlinux.com

遇到的一个小报错

[root@k8s-master01 ingress-nginx]# helm install ingress-nginx -n ingress-nginx .
Error: INSTALLATION FAILED: rendered manifests contain a resource that already exists. Unable to continue with install: ClusterRole "ingress-nginx" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; annotation validation error: missing key "meta.helm.sh/release-name": must be set to "ingress-nginx"; annotation validation error: missing key "meta.helm.sh/release-namespace": must be set to "ingress-nginx"

解决

kubectl get ClusterRoles --all-namespaces | grep ingress
kubectl delete ClusterRole xxxx --all-namespaces

参考https://help.aliyun.com/document_detail/279475.html

七、参考资料

黑马Linux-k8s第三天视频

腾讯课堂

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原文地址：https://www.cnblogs.com/tz90/p/15578338.html