Order

This article mainly studies the appname attribute of eureka

Configuration

eureka.instance.appname

    {
      "sourceType": "org.springframework.cloud.netflix.eureka.EurekaInstanceConfigBean",
      "defaultValue": "unknown",
      "name": "eureka.instance.appname",
      "description": "Get the name of the application to be registered with eureka.",
      "type": "java.lang.String"
    }

You can see that the default is unknown.

EurekaInstanceConfigBean

spring-cloud-netflix-eureka-client-2.0.0.RC1-sources.jar! /org/springframework/cloud/netflix/eureka/EurekaInstanceConfigBean.java

@ConfigurationProperties("eureka.instance")
public class EurekaInstanceConfigBean implements CloudEurekaInstanceConfig, EnvironmentAware {
    //......
    /**
     * Get the name of the application to be registered with eureka.
     */
    private String appname = UNKNOWN;

    @Override
    public void setEnvironment(Environment environment) {
        this.environment = environment;
        // set some defaults from the environment, but allow the defaults to use relaxed binding
        String springAppName = this.environment.getProperty("spring.application.name", "");
        if(StringUtils.hasText(springAppName)) {
            setAppname(springAppName);
            setVirtualHostName(springAppName);
            setSecureVirtualHostName(springAppName);
        }
    }
    //......
}

You can see that the setEnvironment method of the EnvironmentAware interface is implemented here. according to the configuration of the spring.application.name attribute, if there is a value, it is set to the attribute of eureka.instance.appname

Use

Create

spring-cloud-netflix-eureka-client-2.0.0.RC1-sources.jar! /org/springframework/cloud/netflix/eureka/InstanceInfoFactory.java

public class InstanceInfoFactory {

    private static final Log log = LogFactory.getLog(InstanceInfoFactory.class);

    public InstanceInfo create(EurekaInstanceConfig config) {
        LeaseInfo.Builder leaseInfoBuilder = LeaseInfo.Builder.newBuilder()
                .setRenewalIntervalInSecs(config.getLeaseRenewalIntervalInSeconds())
                .setDurationInSecs(config.getLeaseExpirationDurationInSeconds());

        // Builder the instance information to be registered with eureka
        // server
        InstanceInfo.Builder builder = InstanceInfo.Builder.newBuilder();

        String namespace = config.getNamespace();
        if (!namespace.endsWith(".")) {
            namespace = namespace + ".";
        }
        builder.setNamespace(namespace).setAppName(config.getAppname())
                .setInstanceId(config.getInstanceId())
                .setAppGroupName(config.getAppGroupName())
                .setDataCenterInfo(config.getDataCenterInfo())
                .setIPAddr(config.getIpAddress()).setHostName(config.getHostName(false))
                .setPort(config.getNonSecurePort())
                .enablePort(InstanceInfo.PortType.UNSECURE,
                        config.isNonSecurePortEnabled())
                .setSecurePort(config.getSecurePort())
                .enablePort(InstanceInfo.PortType.SECURE, config.getSecurePortEnabled())
                .setVIPAddress(config.getVirtualHostName())
                .setSecureVIPAddress(config.getSecureVirtualHostName())
                .setHomePageUrl(config.getHomePageUrlPath(), config.getHomePageUrl())
                .setStatusPageUrl(config.getStatusPageUrlPath(),
                        config.getStatusPageUrl())
                .setHealthCheckUrls(config.getHealthCheckUrlPath(),
                        config.getHealthCheckUrl(), config.getSecureHealthCheckUrl())
                .setASGName(config.getASGName());

        // Start off with the STARTING state to avoid traffic
        if (!config.isInstanceEnabledOnit()) {
            InstanceInfo.InstanceStatus initialStatus = InstanceInfo.InstanceStatus.STARTING;
            if (log.isInfoEnabled()) {
                log.info("Setting initial instance status as: " + initialStatus);
            }
            builder.setStatus(initialStatus);
        }
        else {
            if (log.isInfoEnabled()) {
                log.info("Setting initial instance status as: "
                        + InstanceInfo.InstanceStatus.UP
                        + ". This may be too early for the instance to advertise itself as available. "
                        + "You would instead want to control this via a healthcheck handler.");
            }
        }

        // Add any user-specific metadata information
        for (Map.Entry<String, String> mapEntry : config.getMetadataMap().entrySet()) {
            String key = mapEntry.getKey();
            String value = mapEntry.getValue();
            // only add the metadata if the value is present
            if (value != null && !value.isEmpty()) {
                builder.add(key, value);
            }
        }

        InstanceInfo instanceInfo = builder.build();
        instanceInfo.setLeaseInfo(leaseInfoBuilder.build());
        return instanceInfo;
    }
}

When InstanceInfo was created here, the value of its appName was eurekainstanceinfo.getappname ()

Query

spring-cloud-netflix-eureka-client-2.0.0.RC1-sources.jar! /org/springframework/cloud/netflix/eureka/serviceregistry/EurekaServiceRegistry.java

    @Override
    public Object getStatus(EurekaRegistration registration) {
        String appname = registration.getInstanceConfig().getAppname();
        String instanceId = registration.getInstanceConfig().getInstanceId();
        InstanceInfo info = registration.getEurekaClient().getInstanceInfo(appname, instanceId);

        HashMap<String, Object> status = new HashMap<>();
        if (info != null) {
            status.put("status", info.getStatus().toString());
            status.put("overriddenStatus", info.getOverriddenStatus().toString());
        } else {
            status.put("status", UNKNOWN.toString());
        }

        return status;
    }

When getting getStatus here, geteurekaclient (). getinstanceinfo is passed into appname

Summary

Spring cloud eureka preferentially uses the spring.application.name value to override the value of eureka.instance.appname, while eureka.instance.appname defaults to unknown. If you find that your service’s appName in eureka is unknown, you need to see if spring.application.name is set.

doc

• Configuring Eureka