Kubernetes 部署 SpringCloud应用实践
一、本文示例
简单实现一个注册中心两个互相调用服务的SpringCloud应用，制作镜像并在k8s环境部署
本地环境：
minikube v1.6.2
java 8
SpringCloud 2.3.2-RELEASE
为保证minikube中可直接使用本地构建的镜像，需要行进行如下设置，使本地docker命令连接到minikube环境中
执行命令：
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eval $(minikube docker-env) |
此时docker 命令已经连接到minikube环境中了，可以使用docker images查看已经不是本地的镜像列表了（别担心该命令只改变了当前会话下的docker命令，关闭或重新开户会话就正常了）
然后按正常逻辑构建镜像即可
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docker build -t xxx . |
最后在写部署文件的Deployment.yaml中将imagePullPolicy设置为IfNotPresent或Never（不去远程拉取，使用本地）
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apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: service-customer
spec:
replicas: 1
template:
metadata:
labels:
app: service-customer
spec:
containers:
- name: service-customer
image: service-customer
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8080
|
二、创建项目
eureka项目：注册中心
service-provider： 服务提供方
service-customer：服务调用方
下面挑重点说一下，完事代码文末有github地址
1）eureka注册中心
pom.xml:
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.... |
主要是引入eureka-server依赖
application.yaml
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spring:
application:
name: eureka
server:
port: 8080
eureka:
client:
register-with-eureka: true
fetch-registry: false
service-url:
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
instance:
hostname: localhost
instance-id: eureka-8080
|
Dockerfile:
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FROM openjdk:8-alpine COPY target/eureka.jar . CMD java -jar eureka.jar |
k8s部署及创建service k8s.yaml:
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apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: eureka
spec:
replicas: 1
template:
metadata:
labels:
app: eureka
spec:
containers:
- name: eureka
image: eureka
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
name: eureka
spec:
type: NodePort
selector:
app: eureka
ports:
- protocol: TCP
port: 8080
targetPort: 8080
|
2) service-provider服务提供方
pom.xml
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.... |
引入eureka client依赖
application.yaml:
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spring:
application:
name: service-provider
eureka:
instance:
instance-id: service-provider
hostname: service-provider
client:
service-url:
# eureka地址使用 k8s的service地址
defaultZone: http://eureka:8080/eureka/
server:
port: 8080
|
Dockerfile:
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FROM openjdk:8-alpine COPY target/service-provider.jar . CMD java -jar service-provider.jar |
k8s部署及创建service k8s.yaml:
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apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: service-provider
spec:
replicas: 1
template:
metadata:
labels:
app: service-provider
spec:
containers:
- name: service-provider
image: service-provider
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
name: service-provider
spec:
selector:
app: service-provider
ports:
- protocol: TCP
port: 8080
targetPort: 8080
|
提供接口服务 HelloController.java:
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@RestController
@RequestMapping("/")
public class HelloController {
@RequestMapping("/hello")
public String hello(){
return "hello world";
}
}
|
3) service-customer服务调用方
pom.xml
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.... |
引入eureka client依赖
application.yaml:
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spring:
application:
name: service-customer
eureka:
client:
service-url:
# eureka地址使用 k8s的service地址
defaultZone: http://eureka:8080/eureka/
instance:
instance-id: service-customer
hostname: service-customer
server:
port: 8080
feign:
hystrix:
enabled: true
|
Dockerfile:
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FROM openjdk:8-alpine COPY target/service-customer.jar . CMD java -jar service-customer.jar |
k8s部署及创建service k8s.yaml:
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apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: service-customer
spec:
replicas: 1
template:
metadata:
labels:
app: service-customer
spec:
containers:
- name: service-customer
image: service-customer
imagePullPolicy: IfNotPresent
ports:
- containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
name: service-customer
spec:
selector:
app: service-customer
type: NodePort
ports:
- protocol: TCP
port: 8080
targetPort: 8080
|
测试接口IndexController.java:
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@RestController
@RequestMapping("/")
public class IndexController {
@Resource
private HelloService helloService;
@RequestMapping("/index")
public String index(){
return helloService.hello();
}
}
|
HelloService.java:
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/**
* 通过feignClient调用服务提供者
*/
@FeignClient(name = "service-provider", fallback = HelloServiceFallback.class)
public interface HelloService {
@RequestMapping("/hello")
String hello();
}
|
HelloServiceFallback.java:
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@Service
public class HelloServiceFallback implements HelloService{
@Override
public String hello() {
return "fallback....";
}
}
|
三、构建部署
首先保证当前终端已经使用的是minikube的docker（可以docker images看一下，镜像列表不是本地环境的就对了）
首先构建部署eureka(进入eureka项目目录):
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# 构建 docker build -t eureka . # 查看镜像 docker images # 部署k8s kubectl apply -f k8s.yaml # 查看deployment kubectl get deployment NAME READY UP-TO-DATE AVAILABLE AGE eureka 1/1 1 1 29s # 查看Service kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE eureka NodePort 10.101.11.23 |
可以看到service映射到nodeport的 30512 可以使用命令查看minikube的ip:
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minikube ip 192.168.64.2 |
在浏览器访问 http://192.168.64.2:30512 就可以打开eureka注册中心了
部署service-provider服务提供方（进入service-provider项目目录）：
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# 构建 docker build -t service-provider . # 查看镜像 docker images # 部署k8s kubectl apply -f k8s.yaml # 查看deployment kubectl get deployment NAME READY UP-TO-DATE AVAILABLE AGE eureka 1/1 1 1 4m18s service-provider 1/1 1 1 7s # 查看Service kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE eureka NodePort 10.101.11.23 |
部署service-customer服务调用方（进入service-customer项目目录）：
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# 构建 docker build -t service-customer . # 查看镜像 docker images # 部署k8s kubectl apply -f k8s.yaml # 查看deployment kubectl get deployment NAME READY UP-TO-DATE AVAILABLE AGE eureka 1/1 1 1 10m service-customer 1/1 1 1 8s service-provider 1/1 1 1 6m18s # 查看Service kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE eureka NodePort 10.101.11.23 |
pod都Running之后，测试一下接口调用 跟上边eureka一样，customer映射到node的prot为 32357
使用浏览器访问 http://192.168.64.2:32357/index 返回：
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hello world |
删除服务提供者的pod:
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kubectl delete pod service-provider-57d69f46c-lltgw |
再次请求： http://192.168.64.2:32357/index 返回：
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fallback.... |
过一会新的pod启动成功后再访问就恢复正常了