K8S学习笔记06 RBAC ,Ingress

集群安全机制

apiserver统一协调：认证 > 鉴权（授权）> 准入控制

认证

传输安全: 对外不暴露8080端口，只能内部访问，对外使用的端口6443

客户端身份认证常用方式

• https证书认证，基于ca证书
• http token认证，通过token来识别用户
• http基本认证，用户名 + 密码认证

鉴权：RBAC

RBAC：基于角色的访问控制，某个角色设置访问内容，然后用户分配该角色后，就拥有该角色的访问权限

角色

• Role：特定命名空间访问权限
• ClusterRole：所有命名空间的访问权限

角色绑定

• roleBinding：角色绑定到主体
• ClusterRoleBinding：集群角色绑定到主体

主体

• user：用户
• group：用户组
• serviceAccount：服务账号

测试

1.创建命名空间

kubectl create ns roledemo

2.在命名空间下创建一个Pod

kubectl run nginx --image=nginx -n roledemo

3.创建角色
tip：这个角色只对pod 有 get、list权限

# 创建
kubectl apply -f rbac-role.yaml
# 查看
kubectl get role -n roledemo

4.角色绑定用户

# 创建角色绑定
kubectl apply -f rbac-rolebinding.yaml
# 查看角色绑定
kubectl get role, rolebinding -n roledemo

5.使用证书识别身份


这里包含了很多证书文件，在TSL目录下，需要复制过来
通过下面命令执行我们的脚本

./rbac-user.sh

测试

# 切换命名空间看输出结果区别
kubectl get pods -n roledemo --kubeconfig=./mary-kubeconfig 

准入控制

就是准入控制器的列表，对api-server的请求进行过滤：如果列表有请求的内容就通过，没有的话 就拒绝

Ingress

前言

原来我们需要将端口号对外暴露，通过 ip + 端口号就可以进行访问

原来是使用Service中的NodePort来实现

在每个节点上都会启动端口
在访问的时候通过任何节点，通过ip + 端口号就能实现访问
但是NodePort还存在一些缺陷

因为端口不能重复，所以每个端口只能使用一次，一个端口对应一个应用
实际访问中都是用域名，根据不同域名跳转到不同端口服务中

Ingress和Pod关系

Pod 和 Ingress 是通过Service进行关联的，而Ingress作为统一入口，由Service关联一组Pod中

• 首先service就是关联我们的pod
• 然后ingress作为入口，首先需要到service，然后发现一组pod
• 发现pod后，就可以做负载均衡等操作

Ingress工作流程

不同域名对应不同的Service，然后service管理不同的pod

需要注意，ingress不是内置的组件，需要我们单独的安装

使用Ingress

• 部署ingress Controller【需要下载官方的】
• 创建ingress规则【对哪个Pod、名称空间配置规则】

使用Ingress对外暴露应用

1.创建一个nginx应用，然后对外暴露端口

# 创建pod
kubectl create deployment web --image=nginx
# 查看
kubectl get pods

对外暴露端口

kubectl expose deployment web --port=80 --target-port=80 --type=NodePort

kubectl get svc

NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP        147m
web          NodePort    10.107.12.59   <none>        80:30812/TCP   38s

2.部署ingress controller

vim ingress-con.yaml

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:
      hostNetwork: true
      # wait up to five minutes for the drain of connections
      terminationGracePeriodSeconds: 300
      serviceAccountName: nginx-ingress-serviceaccount
      nodeSelector:
        kubernetes.io/os: linux
      containers:
        - name: nginx-ingress-controller
          image: lizhenliang/nginx-ingress-controller:0.30.0
          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 -> 101
            runAsUser: 101
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
            - name: https
              containerPort: 443
              protocol: TCP
          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
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown

---

apiVersion: v1
kind: LimitRange
metadata:
  name: ingress-nginx
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  limits:
  - min:
      memory: 90Mi
      cpu: 100m
    type: Container

部署

kubectl apply -f ingress-con.yaml

查看状态

kubectl get pods -n ingress-nginx

需要注意的是 hostNetwork: true，表示对外暴露网络，改成ture是为了让后面访问到

创建Ingress规则

1.创建ingress规则文件，ingress-h.yaml

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: example-ingress
spec:
  rules:
  - host: ingressdemo.com
    http:
      paths:
      - path: /
        backend:
          serviceName: web
          servicePort: 80

部署

kubectl apply -f ingress-h.yaml

ingress.networking.k8s.io/example-ingress created

查看pod

kubectl get pods -n ingress-nginx -o wide

NAME                                       READY   STATUS    RESTARTS   AGE    IP           NODE        NOMINATED NODE   READINESS GATES
nginx-ingress-controller-766fb9f77-g8hgz   1/1     Running   0          5m3s   10.206.0.2   k8s-node1   <none>           <none>

到k8s-node1查看80端口

netstat -antp |grep 80

tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      29326/nginx: master 

2.修改本地hosts文件，添加域名访问规则(k8s-node1的公网IP)

vim /etc/hosts

119.45.233.2 ingressdemo.com

3.通过域名就能访问