Ingress

在Kubernetes中，服务和Pod的IP地址仅可以在集群网络内部使用，对于集群外的应用是不可见的。为了使外部的应用能够访问集群内的服务，在Kubernetes中可以通过NodePort和LoadBalancer这两种类型的服务，或者使用Ingress。Ingress本质是通过http反向代理服务器将外部的http请求转发到集群内部的后端服务。

项目地址

https://github.com/kubernetes/ingress-nginx

部署文件说明：

namespace.yaml

创建一个独立的命名空间 ingress-nginx

https://github.com/kubernetes/ingress-nginx/blob/master/deploy/static/namespace.yaml

apiVersion: v1

kind: Namespace

metadata:

  name: ingress-nginx

  labels:

    app.kubernetes.io/name: ingress-nginx

    app.kubernetes.io/part-of: ingress-nginx

---

configmap.yaml

　　ConfigMap是存储通用的配置变量的，类似于配置文件，使用户可以将分布式系统中用于不同模块的环境变量统一到一个对象中管理；而它与配置文件的区别在于它是存在集群的“环境”中的，并且支持K8S集群中所有通用的操作调用方式。从数据角度来看，ConfigMap的类型只是键值组，用于存储被Pod或者其他资源对象（如RC）访问的信息。这与secret的设计理念有异曲同工之妙，主要区别在于ConfigMap通常不用于存储敏感信息，而只存储简单的文本信息。ConfigMap可以保存环境变量的属性，也可以保存配置文件。创建pod时，对configmap进行绑定，pod内的应用可以直接引用ConfigMap的配置。相当于configmap为应用/运行环境封装配置。

https://github.com/kubernetes/ingress-nginx/blob/master/deploy/static/configmap.yaml

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

---

rbac.yaml

　　负责Ingress的RBAC授权的控制，其创建了Ingress用到的ServiceAccount、ClusterRole、Role、RoleBinding、ClusterRoleBinding

https://github.com/kubernetes/ingress-nginx/blob/master/deploy/static/rbac.yaml

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

---

with-rbac.yaml

　　是Ingress的核心，用于创建ingress-controller。ingress-controller的作用是将新加入的Ingress进行转化为Nginx的配置

https://github.com/kubernetes/ingress-nginx/blob/master/deploy/static/with-rbac.yaml

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:

      # 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: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.26.1

          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

          lifecycle:

            preStop:

              exec:

                command:

                  - /wait-shutdown

---

mandatory.yaml

以上代码清单的合集

部署Ingress-nginx

kubectl apply -f mandatory.yaml

参考文档：

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

https://blog.csdn.net/bbwangj/article/details/82940419

巴特西

kubernetes V1.16 Ingress-nginx部署