JHipster micro-services unable to register properly to Eureka on AWS - spring-boot

Question

I have a Spring Cloud application working well on AWS.
I decided to add JHipster generated micro-services (the JHipster gateway and UAA).
Both of these services register to an existing Eureka Server, like all the previous ones.
Things work fine on a local machine, or running in Docker containers deployed on a EC2 instance on AWS.
However, when deploying on different EC2 instances, the JHipster generated services are not registering correctly. The Eureka UI displays :
Application AMIs Availability Zones Status
HELLO-SERVICE ami-809f84e6 (2) eu-west-1b (1), eu-west-1a (1) UP (2) - i-02eg07053a672ea37 , i-083c2f2204d01f4ba
UAA n/a (2) (2) UP (2) - 97b39345fb59:uaa:9999 , ga6831e52701:uaa:9999
"HELLO-SERVICE" is a simple spring boot app. Eureka displays AWS information, and links it to a private ip/port which is working.
"UAA" is generated by Jhipster. Eureka is missing AWS information for this service, and links it to a 172.17.x.x.x address which is not working.
What bothers me is that both services share the same eureka configuration files :
eureka:
datacenter: cloud
instance:
preferIpAddress: true
client:
healthcheck:
enabled: true
registerWithEureka: true
fetchRegistry: true
region: eu-west-1
preferedSameZone: true
availabilityZones:
eu-west-1: eu-west-1a,eu-west-1b
serviceUrl:
eu-west-1a: http://[eurekainstance]:8761/eureka/
eu-west-1b: http://[eurekainstance]:8761/eureka/
Why would a JHipster generated app and a simple Spring Boot app behave differently while sharing the same configuration ?
I have run out of ideas, any help would be much appreciated!

Answer 1

I'll anwser my own question in case it's useful to someone.
The issue had nothing to do with JHipster or AWS, but with Docker.
Adding an EurekaInstanceConfigBean solved it:
public EurekaInstanceConfigBean eurekaInstanceConfig(InetUtils inet) {
EurekaInstanceConfigBean config = new EurekaInstanceConfigBean(inet);
AmazonInfo info = AmazonInfo.Builder.newBuilder().autoBuild("eureka");
config.setDataCenterInfo(info);
info.getMetadata().put(AmazonInfo.MetaDataKey.localHostname.getName(), info.get(AmazonInfo.MetaDataKey.localIpv4));
config.setHostname(info.get(AmazonInfo.MetaDataKey.localHostname));
config.setIpAddress(info.get(AmazonInfo.MetaDataKey.localIpv4));
config.setNonSecurePort(port);
return config;
}
See the documentation for more information.