SpringCloud的配置中心从数据库中获取config配置

在微服务中，服务的配置文件可以从

1. 本地获取
2. 远程git获取
3. 数据库获取。

本文主要讲解从数据库端获取配置信息。

Config服务端：

配置中心的config文件:

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.47</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>

配置文件如下：

server:
  port: 18080
spring:
  application:
    name: config-server
  datasource: #数据库数据
    url: jdbc:mysql://localhost:30176/config_service?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: test
    password: test
    driver-class-name: com.mysql.jdbc.Driver
  profiles:
    active: jdbc   #配置文件读取类型：从数据库读
  cloud:
    config:
      server:
        jdbc:   #查询SQL中的配置数据
          sql: select distinct cm.cnf_key,cm.cnf_value from applications app,configuration_mapping cm,environments env where 1=1 and cm.application_id = app.id and cm.env_id = env.id and env.enabled ='Y' and app.enabled ='Y' and cm.enabled ='Y' and ( app.application_code = ? or app.application_code = 'common' ) and env.environment_code = ? and cm.label_name = ?
        prefix: config-api
eureka:  #注册中心信息
  instance:
    preferIpAddress: true
    leaseRenewalIntervalInSeconds: 10
    leaseExpirationDurationInSeconds: 30
    metadata-map:
      VERSION: v1
  client:
    serviceUrl:
      defaultZone: http://localhost:8000/eureka/
    registryFetchIntervalSeconds: 10
security:
  basic:
    enabled: false
mybatis:
  mapperLocations: classpath*:/mapper/*.xml
  configuration: # 数据库下划线转驼峰配置
    mapUnderscoreToCamelCase: true

config配置文件也可以从git中获取，对应的配置文件如下，但是

  cloud:
    config:
      server:
        git:
          uri: https://github.com/tanchuntcc/config-repo.git
          username: tanchuntcc
          password: tanchun2016.
    bus:
      enabled: true
      trace:
        enabled: true

SpringBoot启动类注解：

@EnableConfigServer
@SpringBootApplication
@EnableEurekaClient
public class ControlServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ControlServerApplication.class, args);
    }
}

查询配置文件的接口如下：

    @GetMapping("/{applicationId}/{envId}")
    public ResponseEntity<Configurations> selectByConditon(@PathVariable("applicationId") Long applicationId,
                                                           @PathVariable("envId") Long envId) {
        ConfigurationMapping configurationMapping = new ConfigurationMapping();
        configurationMapping.setApplicationId(applicationId);
        configurationMapping.setEnvId(envId);
        configurationMapping.setEnabled("Y");
        List<ConfigurationMapping> configurationMappings = mapper.select(configurationMapping);
        Configurations configurations = new Configurations();
        if (!configurationMappings.isEmpty()){
            BeanUtils.copyProperties(configurationMappings.get(0), configurations);
            LinkedHashMap<String, String> configs = new LinkedHashMap<>();
            for (ConfigurationMapping c : configurationMappings
                    ) {
                configs.put(c.getCnfKey(), c.getCnfValue());
            }
            configurations.setConfigurations(configs);
        }
        LinkedHashMap<String, String> configurationsMap = configurations.getConfigurations();
        if (configurationsMap != null) {
            configurations.setText(convert2Yml(configurationsMap));
        }
        return Optional.ofNullable(configurations)
                .map(result -> new ResponseEntity<>(result, HttpStatus.OK))
                .orElseThrow(() -> new ConfigException("error.find.config"));

application_id表示应用的id，env_id表示环境的id,cnf_num表示不同的服务编码，cnf_key和cnf_value表示配置文件的每一行数据的key和value。数据库的数据如下:

调用接口获取到数据后，获取的数据如下：

获取到数据后,前端写一个简单的页面，就可以在界面上手动修改配置文件了。

当然还可以设置集中不同的环境，如dev,prod环境等。

Config客户端：

config的客户端就是各个服务，在没有配置SpringCloudConfig时,客户端会默认从classpath。当配置了config时,客户端会从Config服务端获取配置信息,因为SoringBoot配置文件的优先级bootstrap.yml大于其他配置文件。配置文件如下：

spring:
  application:
    name: yqcloud-itsm-service
  profiles:
    active: itsm
  cloud:
    config:
      failFast: true
      retry:
        maxAttempts: 6
        multiplier: 1.5
        maxInterval: 2000
      uri: http://localhost:8081  #config服务端地址
      label: default
      enabled: true
      profile: dev

客户端相关的maven包依赖：

      <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-undertow</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-client</artifactId>
        </dependency>