k8s中负载均衡器【ingress-nginx】部署

时间  2020-05-28
标签 k8s 负载 均衡器 ingress-nginx 部署 栏目 负载均衡 繁體版
原文   原文链接

在Kubernetes中，服务和Pod的IP地址仅能够在集群网络内部使用，对于集群外的应用是不可见的。为了使外部的应用可以访问集群内的服务，在Kubernetes 目前 提供了如下几种方案：html

  • NodePort前端

  • LoadBalancerjava

  • Ingressnode

本节主要就ingress和ingress控制器ingress-nginx-controller的部署做简单介绍和记录。python

如下系统组件版本：nginx

云服务器：centos版本7.6.18十、k8s版本1.15.0、docker版本18.06.1-ce、ingress-nginx-controller版本0.25.0git

Ingressgithub

Ingress 组成？

  • 将Nginx的配置抽象成一个Ingress对象，每添加一个新的服务只需写一个新的Ingress的yaml文件便可面试

  • 将新加入的Ingress转化成Nginx的配置文件并使之生效spring

  • ingress controller

  • ingress服务

Ingress 工做原理?

  • ingress controller经过和kubernetes api交互，动态的去感知集群中ingress规则变化，
  • 而后读取它，按照自定义的规则，规则就是写明了哪一个域名对应哪一个service，生成一段nginx配置，
  • 再写到nginx-ingress-controller的pod里，这个Ingress
    controller的pod里运行着一个Nginx服务，控制器会把生成的nginx配置写入/etc/nginx.conf文件中，
  • 而后reload一下使配置生效。以此达到域名分配置和动态更新的问题。

Ingress 能够解决什么问题？

动态配置服务

若是按照传统方式, 当新增长一个服务时, 咱们可能须要在流量入口加一个反向代理指向咱们新的服务. 而若是用了Ingress, 只须要配置好这个服务, 当服务启动时, 会自动注册到Ingress的中, 不须要而外的操做.

减小没必要要的端口暴露

配置过k8s的都清楚, 第一步是要关闭防火墙的, 主要缘由是k8s的不少服务会以NodePort方式映射出去, 这样就至关于给宿主机打了不少孔, 既不安全也不优雅. 而Ingress能够避免这个问题, 除了Ingress自身服务可能须要映射出去, 其余服务都不要用NodePort方式

Ingress当前的实现方式？

在这里插入图片描述

ingress-nginx-controller

目前最新版本的ingress-nginx-controller，用lua实现了当upstream变化时不用reload，大大减小了生产环境中因为服务的重启、升级引发的IP变化致使的nginx reload。

如下就ingress-nginx-controller的部署作简单记录：

yaml以下：

kubectl apply -f {以下文件}
apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---

kind: ConfigMap
apiVersion: v1
metadata:
  name: nginx-configuration
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: tcp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: udp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nginx-ingress-serviceaccount
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: nginx-ingress-clusterrole
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: 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:
      - ""
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses/status
    verbs:
      - update

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: nginx-ingress-role
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - pods
      - secrets
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - configmaps
    resourceNames:
      # Defaults to "<election-id>-<ingress-class>"
      # Here: "<ingress-controller-leader>-<nginx>"
      # This has to be adapted if you change either parameter
      # when launching the nginx-ingress-controller.
      - "ingress-controller-leader-nginx"
    verbs:
      - get
      - update
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ""
    resources:
      - endpoints
    verbs:
      - get

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: nginx-ingress-role-nisa-binding
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: nginx-ingress-role
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: nginx-ingress-clusterrole-nisa-binding
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: nginx-ingress-clusterrole
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-ingress-controller
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/part-of: ingress-nginx
      annotations:
        prometheus.io/port: "10254"
        prometheus.io/scrape: "true"
    spec:
      serviceAccountName: nginx-ingress-serviceaccount
      containers:
        - name: nginx-ingress-controller
          image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.25.0
          args:
            - /nginx-ingress-controller
            - --configmap=$(POD_NAMESPACE)/nginx-configuration
            - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
            - --udp-services-configmap=$(POD_NAMESPACE)/udp-services
            - --publish-service=$(POD_NAMESPACE)/ingress-nginx
            - --annotations-prefix=nginx.ingress.kubernetes.io
          securityContext:
            allowPrivilegeEscalation: true
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            # www-data -> 33
            runAsUser: 33
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          ports:
            - name: http
              containerPort: 80
            - name: https
              containerPort: 443
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10

---

在墙内会拉取不到如下镜像：

quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.25.0

能够使用国内阿里云镜像：

docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/nginx-ingress-controller:0.25.0

安装后，在ingress-nginx命名空间下能够看到pod一直pending，describe pod报以下警告：

在这里插入图片描述

查看master节点默认加了污点，通常不容许pod调度到master节点：

在这里插入图片描述

若是k8s集群只有一个节点，能够在pod的spec下设置容忍该污点：

在这里插入图片描述

即：

spec:      
      tolerations:
      - effect: NoSchedule
        key: node-role.kubernetes.io/master

能够看到ingress-nginx pod被调度到master节点，且变为Running

在这里插入图片描述

看日志报如下警告：

W0714 13:31:04.883127       6 queue.go:130] requeuing &ObjectMeta{Name:sync status,GenerateName:,Namespace:,SelfLink:,UID:,ResourceVersion:,Generation:0,CreationTimestamp:0001-01-01 00:00:00 +0000 UTC,DeletionTimestamp:<nil>,DeletionGracePeriodSeconds:nil,Labels:map[string]string{},Annotations:map[string]string{},OwnerReferences:[],Finalizers:[],ClusterName:,Initializers:nil,ManagedFields:[],}, err services "ingress-nginx" not found

须要创一个名为ingress-nginx的service：

kubectl apply -f {以下文件}
kind: Service
apiVersion: v1
metadata:
  name: ingress-nginx
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  externalTrafficPolicy: Local
  type: LoadBalancer
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
  ports:
    - name: http
      port: 80
      targetPort: http
    - name: https
      port: 443
      targetPort: https

参考：

ingress deploy

https://github.com/kubernetes/ingress-nginx/blob/master/docs/deploy/index.md

Taint和Toleration（污点和容忍）

https://jimmysong.io/kubernetes-handbook/concepts/taint-and-toleration.html

k8s 1.12部署ingress-nginx

https://www.jianshu.com/p/e30b06906b77

本公众号免费提供csdn下载服务，海量IT学习资源，若是你准备入IT坑，励志成为优秀的程序猿，那么这些资源很适合你，包括但不限于java、go、python、springcloud、elk、嵌入式 、大数据、面试资料、前端 等资源。同时咱们组建了一个技术交流群，里面有不少大佬，会不定时分享技术文章，若是你想来一块儿学习提升，能够公众号后台回复【2】，免费邀请加技术交流群互相学习提升，会不按期分享编程IT相关资源。

扫码关注，精彩内容第一时间推给你

image

相关文章
相关标签/搜索
每日一句
    每一个你不满意的现在，都有一个你没有努力的曾经。
本站公众号
   欢迎关注本站公众号,获取更多信息
联系我们 最近搜索 最新文章 沪ICP备13005482号-10 MyBatis教程 SQL 教程 MySQL教程 Java 教程 Thymeleaf 教程 Hibernate教程 Spring教程 Redis教程