2.1 项目代码 引入依赖:
org.springframework.boot spring-boot-starter-web org.springframework.cloud spring-cloud-starter-kubernetes-config 只需要Springboot Web和Spring Cloud Kubernetes Config即可,很简单。Springboot启动类:
@SpringBootApplication public class ConfigMapMain { public static void main(String[] args) { SpringApplication.run(ConfigMapMain.class, args); } } 准备一个EndPoint来展示所读到的配置信息:
@RestController public class PkslowController { @Value("${pkslow.age:0}") private Integer age;
@Value("${pkslow.email:null}") private String email; @Value("${pkslow.webSite:null}") private String webSite; @Value("${pkslow.password:null}") private String password; @GetMapping("/pkslow") public Map<String, String> getConfig() { Map<String, String> map = new HashMap<>(); map.put("age", age.toString()); map.put("email", email); map.put("webSite", webSite); map.put("password", password); return map; }} 默认是为空的,password是从Secret读取,其它从ConfigMap读取。
应用的配置文件如下:
server: port: 8080 spring: application: name: spring-cloud-kubernetes-configmap cloud: kubernetes: config: name: spring-cloud-kubernetes-configmap 这里的spring.cloud.kubernetes.config.name是重点,后续要通过它来找ConfigMap。
加密密码:
$ echo -n “pkslow-pass” | base64 cGtzbG93LXBhc3M= 创建Kubernetes Secret:
kind: Secret apiVersion: v1 metadata: name: spring-cloud-kubernetes-secret namespace: default data: pkslow.password: cGtzbG93LXBhc3M= type: Opaque ConfigMap的内容如下:
kind: ConfigMap apiVersion: v1 metadata: name: spring-cloud-kubernetes-configmap namespace: default labels: app: scdf-server data: application.yaml: |- pkslow: age: 19 email: admin@pkslow.com webSite: www.pkslow.com 要注意的是,这里的名字与前面配置的是一致的,都是spring-cloud-kubernetes-configmap。
接着完成Dockerfile和K8s部署文件就可以了。注意要将Secret的值映射到环境变量:
env: - name: PKSLOW_PASSWORD valueFrom: secretKeyRef: name: spring-cloud-kubernetes-secret key: pkslow.password 2.2 启动与测试 应用会在启动时就去Kubernetes找相应的ConfigMap和Secret:
. ____ _ __ _ _ /\ / ’ __ _ () __ __ _ \ \ \ ( ( )__ | '_ | '| | ’ / ` | \ \ \ \/ )| |)| | | | | || (| | ) ) ) ) ’ || .__|| ||| |__, | / / / / =|_|======|/=//// :: Spring Boot :: (v2.2.5.RELEASE)
2020-08-25 00:13:17.374 INFO 7 — [ main] b.c.PropertySourceBootstrapConfiguration : Located property source: CompositePropertySource {name=‘composite-configmap’, propertySources=[ConfigMapPropertySource {name=‘configmap.spring-cloud-kubernetes-configmap.default’}]} 2020-08-25 00:13:17.376 INFO 7 — [ main] b.c.PropertySourceBootstrapConfiguration : Located property source: CompositePropertySource {name=‘composite-secrets’, propertySources=[]} 访问spring-cloud-kubernetes-configmap.localhost/pkslow,可以正确读取配置,ConfigMap和Secret的内容都获取到了:
3 自动刷新配置 3.1 原理介绍与代码变更 我们需要在Web运行过程中修改配置并使配置生效,有多种模式。修改配置文件如下:
server: port: 8080 spring: application: name: spring-cloud-kubernetes-configmap cloud: kubernetes: config: name: spring-cloud-kubernetes-configmap namespace: default secrets: name: spring-cloud-kubernetes-secret namespace: default enabled: true reload: enabled: true monitoring-config-maps: true monitoring-secrets: true strategy: restart_context mode: event management: endpoint: restart: enabled: true endpoints: web: exposure: include: restart (1) spring.cloud.kubernetes.reload.enabled=true需要打开刷新功能;
(2) 加载策略strategy:
refresh:只对特定的配置生效,有注解@ConfigurationProperties 或 @RefreshScope。 restart_context:整个Spring Context会优雅重启,里面的所有配置都会重新加载。 需要打开actuator endpoint,所以要配置management.endpoint。还要增加依赖:
org.springframework.boot spring-boot-actuator org.springframework.boot spring-boot-actuator-autoconfigure 深圳网站建设www.sz886.com