Precautions for Apollo use

1. Introduce client dependency

<dependency>
		  <groupId>com.ctrip.framework.apollo</groupId>
		  <artifactId>apollo-client</artifactId>
		  <version>1.5.1</version>
</dependency>

notes ：

If there are multiple internal applications to be used at the same time Apollo, Can be Apollo Encapsulated in a single Jar in , For these applications . And the environment can be （DEV、UAT、TEST、PRD）Meta Server Written under the name apollo-env.properties In profile , As shown below ：

dev.meta=http://1.1.1.1:8080
fat.meta=http://apollo.fat.xxx.com
uat.meta=http://apollo.uat.xxx.com
pro.meta=http://apollo.xxx.com

And put it in classpath Next , these Meta Server Is the default value for each environment , You can also follow up by java Start parameter of -Dapollo.meta=metaServerHost, perhaps spring boot Configuration file for application.properties By designation apollo.meta=metaServerHost Methods such as , Make changes .

And then in java The startup parameters only need to pass -Denv=DEV Equal parameter ,apollo Will choose a specific environment Meta Server.

See ：apollo meta server Configuration of

 

2、 The parameter hot update configuration that introduces other variables in the configuration

Apollo It has the function of hot updating parameters , however Apollo Middle configuration Key Must be application.properties or application.yml Medium key, Instead of introducing... In other configuration files key, Otherwise, the hot update will not work , Here are some examples .

The project includes two configuration files ：

application-config.properties
application.properties

The contents are as follows ：

application-config.properties

TEST_KEY=It's a test value

application.properties

spring.profile.active = config
test.key=${TEST_KEY:default_value}

If in apollo The configuration item in is

TEST_KEY=new value

Then modify the configuration item TEST_KEY, Although the application can receive the notification of configuration item modification , But introduce test.key The value of the attribute in the object does not change , Only restart the application will take effect .

In order for the configuration to take effect immediately ,Apollo The configuration item in should be application.properties Medium test.key, Modify configuration item test.key Value , Then introduce test.key The value of the attribute in the object will take effect immediately .

 

3、Apollo About ＠ConfigurationProperties Dynamic refresh of

Comments are used for ＠ConfigurationProperties Configuration injection mode , The following example class ：

@ConfigurationProperties(prefix = "redis.cache")
public class SampleRedisConfig {
  private int expireSeconds;
  private int commandTimeout;

  public void setExpireSeconds(int expireSeconds) {
    this.expireSeconds = expireSeconds;
  }
  public void setCommandTimeout(int commandTimeout) {
    this.commandTimeout = commandTimeout;
  }
}

In view of this Bean, Need to use spring cloud Of EnvironmentChangeEvent and RefreshScope, The implementation is as follows ：

1） rely on spring cloud context, Such as ：

<dependency>
		    <groupId>org.springframework.cloud</groupId>
		    <artifactId>spring-cloud-context</artifactId>
		    <version>2.0.4.RELEASE</version><!-- The version depends on the actual scenario -->
</dependency>

2） stay spring boot Add the following configuration items to the configuration file of ：

spring.boot.enableautoconfiguration=true

3） Realization ApplicationContextAware

import com.ctrip.framework.apollo.model.ConfigChangeEvent;
import com.ctrip.framework.apollo.spring.annotation.ApolloConfigChangeListener;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
import org.springframework.cloud.context.scope.refresh.RefreshScope;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * apollo  Automatically refresh 
 *
 * @author qubianzhong
 * @Date 20:32 2019/11/11
 */
@Component
@Slf4j
public class ApolloRefreshConfig implements ApplicationContextAware {

    ApplicationContext applicationContext;

    @Autowired
    RefreshScope refreshScope;

	// Designated here Apollo Of namespace, It's very important , If you don't specify , By default, only application
    @ApolloConfigChangeListener(value = {ConfigConsts.NAMESPACE_APPLICATION,"business","everything"})
    public void onChange(ConfigChangeEvent changeEvent) {
        for (String changedKey : changeEvent.changedKeys()) {
            log.info("apollo changed namespace:{} Key:{} value:{}", changeEvent.getNamespace(), changedKey, changeEvent.getChange(changedKey));
        }
        refreshProperties(changeEvent);
    }

    public void refreshProperties(ConfigChangeEvent changeEvent) {
        this.applicationContext.publishEvent(new EnvironmentChangeEvent(changeEvent.changedKeys()));
        refreshScope.refreshAll();
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
}

4、 The project startup script on the server boot.sh Add startup parameters

 

java \ 
-Dapollo.autoUpdateInjectedSpringProperties=true \ 
-Dapp.id=apollo-demo  \ 
-Denv=DEV \ 
-Dapollo.meta=http://192.168.10.235:8071 \ 
-Dapollo.bootstrap.enabled=true \ 
-Dapollo.bootstrap.eagerLoad.enabled=true \ 
-Dapollo.bootstrap.namespaces=application \ 
-Dapollo.cacheDir=/opt/data/some-cache-dir \
-jar apollo-demo.jar   

apollo.autoUpdateInjectedSpringProperties： Whether to update the configuration automatically , If you do not want to update automatically, set this value to false, The default value is true

app.id： Project AppId

env： Environment settings , Test environment DEV, Pre release environment UAT, Production environment PRO, There are three ways （ Launch parameters 、 Operating system environment variables and configuration files ） Appoint , See documentation

apollo.meta：apollo Service address , For example, the test environment is http://192.168.10.235:8071

apollo.bootstrap.enabled： Whether the configuration is injected in the startup phase

apollo.bootstrap.eagerLoad.enabled： Whether or not to apollo Before the loading of the log system , So you can get through apollo To manage log related configurations , Such as log level settings , If true, At this stage apollo There will be no log output

apollo.bootstrap.namespaces： Configuration item , This is the same as the Apollo configuration properties The documents correspond to each other , For example, Apollo configured application.properties、db.properties and dubbo.properties Three configuration files , Here we set the value to application,db,dubbo

apollo.cacheDir： Custom cache path

 

Script namespaces The default value is application, So the default reading is Apollo application.properties The configuration file .

If there are too many parameters , Or other needs , If you need to add multiple configuration files , It is necessary to contact the operation and maintenance students to cooperate in modifying the project jenkins To configure , modify namespaces Parameters . Under normal circumstances, it is recommended to use only one application.properties The configuration file

 

Details see Apollo Java Official documents used ：Apollo Java Client user guide