配置参数参考：微服务架构：Eureka参数配置项详解 - 风中程序猿 - 博客园
                          Spring Cloud Eureka（四）：Eureka 配置参数说明 - IT码客 - 博客园

一、制作docker镜像

文件所在测试k8s集群 master1 

/home/sunwenbo/test/docker/eureka

目录树
eureka/
├── application.yaml
├── Dockerfile
└── entrypoint.sh

application.yaml

eureka:
  instance:
    #eureka客户需要多长时间发送心跳给eureka服务器，表明它仍然活着,默认为30 秒
    leaseRenewalIntervalInSeconds: 10
    #Eureka服务器在接收到实例的最后一次发出的心跳后，需要等待多久才可以将此实例删除，默认为90秒
    leaseExpirationDurationInSeconds: 30
    metadata-map:
      VERSION: 1.0.0
    #与此实例相关联的主机名，是其他实例可以用来进行请求的准确名称
    hostname: ${MY_POD_NAME}.register-server
    #以IP地址注册到服务中心，相互注册使用IP地址,默认false
    prefer-ip-address: false
  client:
    #客户端是否获取eureka服务器注册表上的注册信息，默认为true
    fetch-registry: ${EUREKA_CLIENT_FETCH_REGISTRY:true}
    #指示此实例是否应将其信息注册到eureka服务器以供其他服务发现，默认为false
    register-with-eureka: ${EUREKA_CLIENT_REGISTER_WITH_EUREKA:true}
    #可用区域映射到与eureka服务器通信的完全限定URL列表。每个值可以是单个URL或逗号分隔的备用
    serviceUrl:
      defaultZone: ${EUREKA_DEFAULT_ZONE:http://register-server-0.register-server:8000/eureka/,http://register-server-1.register-server:8000/eureka/,http://register-server-2.register-server:8000/eureka/}
    #从eureka服务器注册表中获取注册信息的时间间隔（s），默认为30秒
    registryFetchIntervalSeconds: 5
    #指示eureka客户端是否禁用增量提取
    disable-delta: true
  server:
    #过期实例应该启动并运行的时间间隔，单位为毫秒
    evictionIntervalTimerInMs: 4000
    #启用自我保护机制，默认为true
    enable-self-preservation: ${EUREKA_SERVER_ENABLE_SELF_PRESERVATION:true}

Dockerfile

FROM harbor.int.xxx-inc.com/eureka/eureka-1.0.0
RUN mkdir /config
COPY application.yaml /config
ADD entrypoint.sh /usr/bin/entrypoint.sh
EXPOSE 8000
CMD ["entrypoint.sh"]

entrypoint.sh

#!/bin/bash
java -XX:+UnlockExperimentalVMOptions -XX:+UseCGroupMemoryLimitForHeap -jar /eureka.jar  --spring.config.location=/config/application.yaml

docker build -t harbor.int.xxx-inc.com/eureka/eureka:latest .
docker push harbor.int.xxx-inc.com/eureka/eureka:latest

二、k8s 部署StatefulSet 有状态 Eureka 配置无头服务

/home/sunwenbo/test/kubernetes

eureka/
├── eureka-statefulSet.yaml
├── eureka-svc.yaml
└── ingress-eureka.yaml

eureka-statefulSet.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: register-server
  labels:
    service: register-server
spec:
  replicas: 3
  serviceName: register-server
  selector:
    matchLabels:
      service: register-server
  template:
    metadata:
      labels:
        service: register-server
      annotations:
        service: register-server
    spec:
      containers:
        - name: register-server
          image: harbor.int.xxx-inc.com/eureka/eureka
          imagePullPolicy: Always
          env:
          - name: MY_POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          ports:
          - name: http
            containerPort: 8000
            protocol: TCP
          resources:
            requests:
              memory: "100Mi"
              cpu: "1"
            limits:
              memory: "4Gi"
              cpu: "2"
          livenessProbe:
            tcpSocket:
              port: 8000
            failureThreshold: 3
            initialDelaySeconds: 30
            periodSeconds: 5
            successThreshold: 1
            timeoutSeconds: 10
          readinessProbe:
            httpGet:
              path: /actuator/health
              port: 8001
              scheme: HTTP
            failureThreshold: 3
            initialDelaySeconds: 30
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10

eureka-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: register-server
  labels:
    service: register-server
spec:
  clusterIP: None
  type: ClusterIP
  ports:
    - port: 8000
      targetPort: http
      protocol: TCP
      name: http
  selector:
    service: register-server

ingress-eureka.yaml

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: ingress-eureka
  namespace: default
  annotations:
    kubernetes.io/ingress.class: ingress-nginx1
spec:
  rules:
  - host: test.eureka.xxx-inc.com
    http:
      paths:
      - path: /
        backend:
          serviceName: register-server
          servicePort: 8000

部署命令

cd /home/sunwenbo/test/kubernetes/eureka
kubectl  apply -f ./

三、使用Python 模拟服务注册

eureka-demo.py

# coding:utf-8
import tornado.httpserver
import tornado.ioloop
import tornado.options
from tornado.web import RequestHandler
import py_eureka_client.eureka_client as eureka_client
from tornado.options import define, options
 
define("port", default=32001, help="run on the given port", type=int)
 
class IndexHandler(RequestHandler):
    def get(self):
        username = self.get_argument('username', 'Hello')
        self.write(username + ', Administrator User!')
 
#restfulAPI功能实现在这里
class TestHandler(RequestHandler):
    def get(self):
        self.write("hello world   welcome to you")
 
def eurekaclient():
    tornado.options.parse_command_line()
    # 注册eureka服务
    eureka_client.init(eureka_server="http://test.eureka.xxx-inc.com/eureka",
                                       app_name="python-test02",
                                       instance_port=32001)
    #提供外部调用的接口
    app = tornado.web.Application(handlers=[(r"/", IndexHandler),
                                            (r"/test", TestHandler)])
    http_server = tornado.httpserver.HTTPServer(app)
    http_server.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()
 
    print("eureka exec")
 
if __name__ == "__main__":
    eurekaclient()

运行完上述python程序后，Eureka web页面会显示如下注册信息

该日志为为euerka-2的日志，可以看到每10秒 euerka会调用euerka-client从eureka服务获得所有实例注册表信息，并更新自己的实例注册表信息。

当停掉一个注册服务时，euerka会很敏捷的发现该服务的状态，并修改该服务的状态为DOWN，后台日志也会提示该服务的状态已经为DOWN如下图

 

因为euerka会每10秒定时的更新注册表信息，之后会将消息通知到其他的euerka server，随后同步信息