kubernetes 服务 - 可以在 3 个不同的变量值（端口、目标端口、节点端口）上使用相同的端口值（即 10002）吗？

Question

kubernetes 服务 - 相同的端口值（即 10002）可以用于 3 个不同的变量值（端口、目标端口、节点端口）吗？

即

spec:
  type: NodePort
  ports:
  - port: 10002
    name: webapi
    targetPort: 10002
    nodePort: 10002

Answer 1

在 k8s 服务规范中

目标端口： Pod 的端口

端口: 服务端口

NodePort: Nodepool 的端口

因此，port和targetport需要相同，nodeport的值是动态来的。（默认值：30000-32767）

您可以使用以下命令获取详细信息kubectl explain service.spec.ports

FIELDS:
   name <string>
     The name of this port within the service. This must be a DNS_LABEL. All
     ports within a ServiceSpec must have unique names. This maps to the 'Name'
     field in EndpointPort objects. Optional if only one ServicePort is defined
     on this service.

   nodePort     <integer>
     The port on each node on which this service is exposed when type=NodePort
     or LoadBalancer. Usually assigned by the system. If specified, it will be
     allocated to the service if unused or else creation of the service will
     fail. Default is to auto-allocate a port if the ServiceType of this Service
     requires one. More info:
     https://kubernetes.io/docs/concepts/services-networking/service/#type-nodeport

   port <integer> -required-
     The port that will be exposed by this service.

   protocol     <string>
     The IP protocol for this port. Supports "TCP" and "UDP". Default is TCP.

   targetPort   <string>
     Number or name of the port to access on the pods targeted by the service.
     Number must be in the range 1 to 65535. Name must be an IANA_SVC_NAME. If
     this is a string, it will be looked up as a named port in the target Pod's
     container ports. If this is not specified, the value of the 'port' field is
     used (an identity map). This field is ignored for services with
     clusterIP=None, and should be omitted or set equal to the 'port' field.
     More info:
     https://kubernetes.io/docs/concepts/services-networking/service/#defining-a-service

If you want a specific port number, you can specify a value in the nodePort field, and the system will allocate you that port or else the API transaction will fail (i.e. you need to take care about possible port collisions yourself). The value you specify must be in the configured range for node ports. nodeport

Answer 2

服务ip和端口是虚拟的。它们没有连接到网络接口。您可以使用任何端口作为服务端口。它不需要与 pods 目标端口相同。

kubernetes 中的默认节点端口范围是 30000-32767。您还可以定义自定义范围。

因此，pod/server/nodeport 可能有相同的端口，如果端口已打开以供连接

kubernetes 服务 - 可以在 3 个不同的变量值（端口、目标端口、节点端口）上使用相同的端口值（即 10002）吗？

kubernetes service - can the same port value (ie 10002) be used on 3 different variable values (port, targetport, nodeport)?

docker

kubernetes

kubernetes-ingress