Kubernetes-没有选择器的服务 [英] Kubernetes - services without selector
问题描述
我在没有选择器的情况下在Kubernetes的服务中苦苦挣扎.群集通过kops安装在AWS上.我有一个带有3个Nginx Pod的部署，暴露了端口80:
I'm struggling with Kubernetes' service without a selector. The cluster is installed on AWS with the kops. I have a deployment with 3 nginx pods exposing port 80:
apiVersion: apps/v1
kind: Deployment
metadata:
name: ngix-dpl # Name of the deployment object
labels:
app: nginx
spec:
replicas: 3 # Number of instances in the deployment
selector: # Selector identifies pods to be
matchLabels: # part of the deployment
app: nginx # by matching of the label "app"
template: # Templates describes pods of the deployment
metadata:
labels: # Defines key-value map
app: nginx # Label to be recognized by other objects
spec: # as deployment or service
containers: # Lists all containers in the pod
- name: nginx-pod # container name
image: nginx:1.17.4 # container docker image
ports:
- containerPort: 80 # port exposed by container
创建部署后，我记下了IP地址:
After creation of the deployment, I noted the IP addresses:
$ kubectl get pods -o wide | awk {'print $1" " $3" " $6'} | column -t
NAME STATUS IP
curl Running 100.96.6.40
ngix-dpl-7d6b8c8944-8zsgk Running 100.96.8.53
ngix-dpl-7d6b8c8944-l4gwk Running 100.96.6.43
ngix-dpl-7d6b8c8944-pffsg Running 100.96.8.54
并创建了一个服务于IP地址的服务:
and created a service that should serve the IP addresses:
apiVersion: v1
kind: Service
metadata:
name: dummy-svc
labels:
app: nginx
spec:
ports:
- protocol: TCP
port: 80
targetPort: 80
---
apiVersion: v1
kind: Endpoints
metadata:
name: dummy-svc
subsets:
- addresses:
- ip: 100.96.8.53
- ip: 100.96.6.43
- ip: 100.96.8.54
ports:
- port: 80
name: http
服务已成功创建:
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
dummy-svc ClusterIP 100.64.222.220 <none> 80/TCP 32m
kubernetes ClusterIP 100.64.0.1 <none> 443/TCP 5d14h
不幸的是，我尝试通过服务从同一名称空间的另一个Pod连接到Nginx失败:
Unfortunately, my attempt to connect to the nginx through the service from another pod of the same namespace fails:
$ curl 100.64.222.220
curl: (7) Failed to connect to 100.64.222.220 port 80: Connection refused
我可以直接成功连接到nginx吊舱:
I can successfully connect to the nginx pods directly:
$ curl 100.96.8.53
<!DOCTYPE html>
<html>
<head>
....
我注意到我的服务没有任何端点.但是我不确定是否应该在此处显示手动端点:
I noticed that my service does not have any endpoints. But I'm not sure that the manual endpoints should be shown there:
$ kubectl get svc/dummy-svc -o yaml
apiVersion: v1
kind: Service
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app":"nginx"},"name":"dummy-svc","namespace":"default"},"spec":{"ports":[{"port":80,"protocol":"TCP","targetPort":80}]}}
creationTimestamp: "2019-11-22T08:41:29Z"
labels:
app: nginx
name: dummy-svc
namespace: default
resourceVersion: "4406151"
selfLink: /api/v1/namespaces/default/services/dummy-svc
uid: e0aa9d01-0d03-11ea-a19c-0a7942f17bf8
spec:
clusterIP: 100.64.222.220
ports:
- port: 80
protocol: TCP
targetPort: 80
sessionAffinity: None
type: ClusterIP
status:
loadBalancer: {}
我知道这不是服务的正确用例，使用pod选择器会使它工作.但是我想强调一下为什么这种配置不起作用.我不知道在哪里寻找解决方案.任何提示将不胜感激.
I understand that it is not a proper use case for services and using of a pod selector will bring it to work. But I want to understend why this configuration does not work. I don't know where to look for the solution. Any hint will be appreciated.
推荐答案
如果您从端点配置中删除名称"字段，它将起作用.它应该看起来像这样:
it works if you remove the "name" field from the endpoints configuration. it should look like this:
apiVersion: v1
kind: Endpoints
metadata:
name: dummy-svc
subsets:
- addresses:
- ip: 172.17.0.4
- ip: 172.17.0.5
- ip: 172.17.0.6
ports:
- port: 80
这篇关于Kubernetes-没有选择器的服务的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
