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理论

1. 什么是ingress

   简单理解，ingress就是将pod所提供的服务暴露出来，能够让k8s集群外部访问到对应的服务。

2. 为什么要使用ingress？

   除了可以使用ingress。我目前使用过的还有nodeport，nodeport直接映射集群中每台主机的端口，可以通过访问集群中任意一台主机的地址+端口来访问对应的服务。

   用nodeport不好么？多出了这么个东西是为了解决什么问题？

   我仔细琢磨了下，k8s的设计思想就是将整个k8s集群作为逻辑上的一台主机，每个pod相当于一个或一组相关进程。

   对，我们一定可以这么理解：nodeport就相当于在Linux主机上的服务进程端口，用户访问时直接通过IP+端口可以访问；那么ingress（或许叫做ingress-controller更合适）就是一个nginx之类的反向代理，将需要反向代理的服务全部都塞到配置文件里，我们只需要访问ingress暴露出来的端口就可以（通过不同域名来区分，或者是根据url来区分）。

   但是和Linux主机所不同的是：就算我们不是很理解，但是要知道一个事实，Linux主机上的服务进程端口就算用nginx做统一管理，统一反向代理；但是它自身不会减少主机暴露的端口，只是它会对用户层面隐藏掉。但是ingress就不一样了，它是真正减少暴露宿主机的端口的；我们创建pod提供服务，肯定要暴露出来端口啊，它是怎么做到的？这是当然，只不过笔者能力有限，我尝试着这样说明一下：创建pod提供必需要暴露端口，这是进程之间通信也好，用户访问也好，都需要的。只不过在k8s中，有了service这个概念，service的端口开放，但是不占用宿主机的，如果我们不做别的操作，它只能在集群内部进行访问。

   ingress就是如此，接受到请求，根据配置转发，反向代理到后面的service

   如上理论个人理解，不官方

撸部署撸配置

1. 之前称呼的ingress有些不严谨，ingress相当于使用nginx的server段，而ingress-controller可以类比nginx自身，而ingress-controller有很多中，Nginx，HAProxy，Envoy，Traefik，只是nginx比较广泛，好理解。

2. 部署一个ingress-nginx

   官方yaml文件地址：https://raw.githubusercontent.com/kubernetes/ingress-nginx/nginx-0.30.0/deploy/static/mandatory.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:
         # 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:0.30.0
             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
   

配置很多，原理很简单，这个Pod本身，就是一个监听Ingress对象以及它所代理的服务变化的控制器。当一个新的Ingress对象由用户创建后，nginx-ingress-controller就会根据Ingress对象里定义的内容，生成副本对应的Nginx配置文件（/etc/nginx/nginx.conf），并使用这个配置文件启动一个Nginx服务。

3. 接下来的配置就相当于，我们创建了一个nginx，接下来要为它指定访问的入口，也就是定义service

   apiVersion: v1
   kind: Service
   metadata:
     name: ingress-nginx
     namespace: ingress-nginx
     labels:
       app.kubernetes.io/name: ingress-nginx
       app.kubernetes.io/part-of: ingress-nginx
   spec:
     type: NodePort
     ports:
       - name: http
         port: 80
         targetPort: 80
         protocol: TCP
         nodePort: 80
       - name: https
         port: 443
         targetPort: 443
         protocol: TCP
         nodePort: 443
     selector:
       app.kubernetes.io/name: ingress-nginx
       app.kubernetes.io/part-of: ingress-nginx
   

   如配置所写：我将宿主机的80映射到容器的默认80，443对应443，很方便

4. 好，那再接下来，我们有了nginx反向代理，我们要配置它代理谁了；我这里又个后端的私有服务端口8080

   不过在这之前，我想配置https了，我下面说说，https和http分别的配置

   https：

   ? 首先将已有的crt和key文件创建成secret对象，以便使用

   ? ingress-secret.yml

   apiVersion: v1
   data:
     tls.crt: UVVITUFHR0dHaDBkSEE2Ckx5OXZZM053TG1kdlpHRmtaS
     #你的crt经过base64编码之后放到这里，我这只是示范，注意空格换行都不要。
     #cat key  | base64 | tr ‘\n‘ ‘ ‘ | sed  ‘s/ //g‘
     tls.key: xVWE3Q2FDbjNobis4QzkxM2FyOUNSNXZ
     #同上，值得注意的是tls.crt和tls.key这个字段，我之前以为只是一个名称，可以改写。但是这两个字段是关键词，死的，不能动。
   kind: Secret
   metadata:
     name: ingress-secret
     namespace: default
     #注意名称空间，要和待会我创建的ingress在一个名称空间内，否则不生效
   type: kubernetes.io/tls
   

   ? ingress.yml，创建ingress，和提供服务的pod的service端口必须对应。

   apiVersion: extensions/v1beta1
   kind: Ingress
   metadata:
     name: keycloak
     namespace: default
   spec:
     tls:
       - hosts:
         - key.123456.com
         secretName: ingress-secret
         #之前的secretname字段必须相同
     rules:
     - host: key.123456.com
       http:
         paths:
         - backend:
             serviceName: keycloak
             servicePort: 8080
   

   自行使用apply进行创建，并查看验证,严格注意名称空间

   http:文件示例

   apiVersion: extensions/v1beta1
   kind: Ingress
   metadata:
     name: ***
     namespace: kube-system
   spec:
     rules:
     - host: dashboard.mritd.me
       http:
         paths:
         - backend:
             serviceName: kubernetes-dashboard
             servicePort: 80
     - host: kibana.mritd.me
       http:
         paths:
         - backend:
             serviceName: kibana-logging
             servicePort: 5601
   

k8s资源对象-ingress通俗理解及配置使用

标签：理论   static   update   base64编码   github   account   lin   val   def   

原文地址：https://www.cnblogs.com/jojoword/p/12711584.html