kubernetes部署ingress-nginx-contro

Ingress部署流程：
1.部署Ingress
1.1部署ingress-nginx
1.2部署Service

2.部署应用
2.1部署Service与Pod
2.2创建Ingress

在Kubernetes中，服务和Pod的IP地址仅在集群内部网络内部使用，对于集群的应用是不可见的。
为了使外部的应用能够访问集群内的服务，在Kubernetes目前提供了以下几种方案：
1）NodePort
2）LoadBalancer
3）Ingress

1）Ingress组成
Ingress 是反向代理规则，用来规定 HTTP/S 请求应该被转发到哪个 Service 上，比如根据请求中不同的 Host 和 url 路径
让请求落到不同的 Service 上；
Ingress Controller 就是一个反向代理程序，它负责解析 Ingress 的反向代理规则，如果 Ingress 有增删改的变动，
所有的 Ingress Controller 都会及时更新自己相应的转发规则，当 Ingress Controller 收到请求后就会根据这些规则
将请求转发到对应的 Service；

2）Ingress工作原理
1）Ingress controller通过与Kubernetes api进行交互，动态的感知集群中Ingress规则的变化；
2）然后读取它，按照自定义的规则，规则就是写明了哪个域名对应哪个service，生成一段nginx配置；
3）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；
4）然后reload一下使配置生效。以此达到域名分别配置和动态更新的问题；

3） Ingress可以解决什么问题？
1）动态配置服务
如果是按照传统方式，当新增加一个服务时，我们可能需要在流量入口部署一台反向代理服务器指向我们新的K8s服务，
而如果使用了Ingress，则只需配置好这个服务，当服务启动时，便会自动注册到Ingress中，不需要额外的操作；
2）减少不必要的端口映射
配置过k8s的都清楚, 第一步是要关闭防火墙的, 主要原因是k8s的很多服务会以NodePort方式映射出去, 这样就相当于给宿主机打了很多孔, 
既不安全也不优雅. 而Ingress可以避免这个问题, 除了Ingress自身服务可能需要映射出去, 其他服务都不用NodePort方式；


Ingress作用：
ingress 仅是用于定义流量转发和调度的通用格式的配置信息，
它们需要转换为特定的具有http协议转发的和调度功能的应用程序(如nginx、haproxy、traefik等)
的配置文件，并由响应 的应用程序生成响应的配置文件完成流量转发。

1.部署ingress-nginx

[16:57:13root@k8s-master-1 ~/nfs/lk/nginx-ingress]#cat ingress-nginx-controller.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:
      - "extensions"
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - "extensions"
    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:0.24.1
          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


2.部署Service
[16:58:27root@k8s-master-1 ~/nfs/lk/nginx-ingress]#cat ingress-svc.yaml 
apiVersion: v1
kind: Service
metadata:
  name: ingress
  namespace: ingress-nginx
spec:
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
  ports:
  - name: http
    port: 80
    nodePort: 40080
  - name: https
    port: 443
    nodePort: 40443
  type: NodePort
注释：此时已部署完ingress-nginx-controller，具有7层代理功能


3.部署Pod与Service
[16:58:48root@k8s-master-1 ~/nfs/lk/nginx-ingress]#cat nginx.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  namespace: kevin
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
      rel: beta
  template:
    metadata:
      namespace: kevin
      labels:
        app: nginx
        rel: beta
    spec:
      containers:
      - name: myapp
        image: nginx:alpine
---
apiVersion: v1
kind: Service
metadata:
  name: nginx
  namespace: kevin
spec:
  selector:
    app: nginx
    rel: beta
  ports:
  - name: http
    port: 80
    targetPort: 80


4.创建Ingress
[16:58:30root@k8s-master-1 ~/nfs/lk/nginx-ingress]#cat myapp-ingress.yaml 
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: nginx
  namespace: kevin
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    kubernetes.io/ingress.class: "nginx"
spec:
  rules:
  - host: www.kevinxxx.com
    http:
      paths:
      - path: /
        backend:
          serviceName: nginx
          servicePort: 80


[17:06:08root@k8s-master-1 ~/nfs/lk/nginx-ingress]#kubectl get pods -n ingress-nginx
NAME                                        READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-59b9f5d675-v758z   1/1     Running   0          65m
[17:08:20root@k8s-master-1 ~/nfs/lk/nginx-ingress]#kubectl get svc -n ingress-nginx
NAME      TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE
ingress   NodePort   10.66.113.207   <none>        80:40080/TCP,443:40443/TCP   64m
[17:08:26root@k8s-master-1 ~/nfs/lk/nginx-ingress]#kubectl get pod -n kevin -o wide
NAME                     READY   STATUS    RESTARTS   AGE   IP            NODE           NOMINATED NODE   READINESS GATES
nginx-5db4499c6c-2wl4r   1/1     Running   0          23m   10.80.0.232   k8s-master-1   <none>           <none>
nginx-5db4499c6c-7zlpf   1/1     Running   0          23m   10.80.2.32    k8s-node-1     <none>           <none>
[17:08:31root@k8s-master-1 ~/nfs/lk/nginx-ingress]#kubectl get svc -n kevin
NAME    TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)   AGE
nginx   ClusterIP   10.66.17.91   <none>        80/TCP    23m
[17:08:37root@k8s-master-1 ~/nfs/lk/nginx-ingress]#kubectl  get ingress -n kevin
NAME    CLASS    HOSTS              ADDRESS   PORTS   AGE
nginx   <none>   www.kevinxxx.com             80      55m
[17:08:42root@k8s-master-1 ~/nfs/lk/nginx-ingress]#kubectl describe ingress -n kevin
Name:             nginx
Namespace:        kevin
Address:          
Default backend:  default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
Rules:
  Host              Path  Backends
  ----              ----  --------
  www.kevinxxx.com  
                    /   nginx:80 (10.80.0.232:80,10.80.2.32:80)
Annotations:        kubernetes.io/ingress.class: nginx
                    nginx.ingress.kubernetes.io/rewrite-target: /
Events:
  Type    Reason  Age   From                      Message
  ----    ------  ----  ----                      -------
  Normal  CREATE  55m   nginx-ingress-controller  Ingress kevin/nginx

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