consul client must be configured to serve instance name and ID micro, micro service starts when the need to register the name and ID to the registry, follow-up call between micro-services also need to use.
Name can be configured in two ways, highest to lowest priority. Neither configure the default service name for the application
spring.cloud.consul.discovery.service-name
spring.application.name
ID can be a plurality of configuration items configuration, the following configuration can be five, highest to lowest priority.
spring.cloud.consul.discovery.instance-id
vcap.application.instance_id
spring.application.name和spring.application.instance_id搭配,'-'分隔
spring.application.name和server.port搭配,'-'分隔
spring.application.name
spring.application.instance_id
If no start being given, the following relevant log, the log can also be seen, the configuration requirements must start with a letter, an alphanumeric or end.
Caused by: java.lang.IllegalArgumentException: Consul service ids must not be empty, must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen: 8081
at org.springframework.cloud.consul.serviceregistry.ConsulAutoRegistration.normalizeForDns(ConsulAutoRegistration.java:179) ~[spring-cloud-consul-discovery-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.cloud.consul.serviceregistry.ConsulAutoRegistration.getInstanceId(ConsulAutoRegistration.java:170) ~[spring-cloud-consul-discovery-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.cloud.consul.serviceregistry.ConsulAutoRegistration.registration(ConsulAutoRegistration.java:78) ~[spring-cloud-consul-discovery-2.0.1.RELEASE.jar:2.0.1.RELEASE]
See Codeorg.springframework.cloud.consul.serviceregistry.ConsulAutoRegistration
public static ConsulAutoRegistration registration(AutoServiceRegistrationProperties autoServiceRegistrationProperties, ConsulDiscoveryProperties properties, ApplicationContext context, List<ConsulRegistrationCustomizer> registrationCustomizers, HeartbeatProperties heartbeatProperties) {
NewService service = new NewService();
//注册到consul服务端时显示的微服务名称,优先级从高到低:
//配置项spring.cloud.consul.discovery.service-name
//配置项spring.application.name
//默认值application
String appName = getAppName(properties, context.getEnvironment());
//注册到consul服务端时显示的微服务Id,优先级从高到低:
//配置项spring.cloud.consul.discovery.instance-id
//配置项vcap.application.instance_id
//配置项spring.application.name和spring.application.instance_id,用':'拼接
//配置项spring.application.name和server.port,用':'拼接
//配置项spring.application.name
//配置项spring.application.instance_id
//注意,内部的normalizeForDns方法,用于规范化应用名称、ID等,把非数字字符串转换成'-'连接符
//比如spring.application.name=sc--test,server.port=8080,拼成的id为sc--test:8080,经过normalizeForDns方法就转换成了sc-test-8080
service.setId(getInstanceId(properties, context));
if(!properties.isPreferAgentAddress()) {
service.setAddress(properties.getHostname());
}
//微服务应用名称也必须符合规范,字母开始,字母或数字结尾
service.setName(normalizeForDns(appName));
//设置标签,spring.cloud.consul.discovery.tags
service.setTags(createTags(properties));
if(properties.getPort() != null) {
service.setPort(properties.getPort());
setCheck(service, autoServiceRegistrationProperties, properties, context, heartbeatProperties);
}
ConsulAutoRegistration registration = new ConsulAutoRegistration(service, autoServiceRegistrationProperties, properties, context, heartbeatProperties);
customize(registrationCustomizers, registration);
return registration;
}
//字符串不能为空,首字符必须为字母,尾字符必须为字母或数字,所有非字母数字的字符统一转换成'-'连接符,同时多个连续连接符转换成一个'-'.
public static String normalizeForDns(String s) {
if(s != null && Character.isLetter(s.charAt(0)) && Character.isLetterOrDigit(s.charAt(s.length() - 1))) {
StringBuilder normalized = new StringBuilder();
Character prev = null;
char[] var3 = s.toCharArray();
int var4 = var3.length;
for(int var5 = 0; var5 < var4; ++var5) {
char curr = var3[var5];
Character toAppend = null;
if(Character.isLetterOrDigit(curr)) {
toAppend = Character.valueOf(curr);
}
//不为数字和字母的字符转换成'-'分隔符,连续多个非字母数字字符转换成一个'-'分隔符
//这里做了一层判断,只有在前一个字符为字母数字的时候,才把当前的字符转换成'-'; 如果前一个为'-'则这个字符忽略不拼接.
//其实这里的prev只有在第一次的时候为null但是第一次的时候走不到else if这个条件
else if(prev == null || prev.charValue() != 45) {
toAppend = Character.valueOf('-');
}
if(toAppend != null) {
normalized.append(toAppend);
prev = toAppend;
}
}
return normalized.toString();
} else {
throw new IllegalArgumentException("Consul service ids must not be empty, must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen: " + s);
}
}