Netfilx eureka server - client booth in docker at gitlab ci; 400 bad request

Question

I'm working with two apps, one of them is server-app (Netflix eureka server) and the other is the client-app, they works perfectly on my machine, client registers on server w/o probs, but when I upload them to gitlab and a pipeline starts, booth apps works but the registry is not successfully made. They are in the same network, the server doesn't register itself, the client-app has its configs, I think, fine, the apps work fine, one by one, I really don't know what to do, I've looked on the official spring docs, official eureka docs, on gitlabs docs, yt videos, here, google but nothing..

So, let's go with the data

<!-- This is the dependency I'm using on server-app (Eureka server) -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    <version>3.1.2</version>
</dependency>

And

<!-- This is the dependency I'm using on client-app -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    <version>3.1.2</version>
</dependency>

The server-app configs

spring:
  application:
    name: registry-app

server:
  port: 5160
eureka:
  server:
    hostname: ${HOST_IP} # This is the server ip, whit hostname the services didn't find between them
    prefer-ip-address: false # I've tried in true and false, same error
  client:
    register-with-eureka: false
    fetch-registry: false

The client-app configs

spring:
  application:
    name: client-app
server:
  port: 5161
eureka:
  server:
    hostname: ${HOST_IP}
    prefer-ip-address: false
  client:
    register-with-eureka: true
    fetch-registry: false
    service-url:
      defaultZone: http://${HOST_IP}:5160/eureka

server-app Main Class

@SpringBootApplication
@EnableEurekaServer
public class RegistryServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(RegistryServerApplication.class, args);
    }

}

client-app Main Class

@SpringBootApplication
@EnableEurekaClient
@EnableConfigServer
public class ConfigServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(ConfigServerApplication.class, args);
    }

}

The first error that the client-app throws is

WARN 1 --- [nfoReplicator-0] c.n.d.s.t.d.RetryableEurekaHttpClient    : Request execution failure with status code 400; retrying on another server if available

And then...

com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server
    at com.netflix.discovery.shared.transport.decorator.RetryableEurekaHttpClient.execute(RetryableEurekaHttpClient.java:112) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$1.execute(EurekaHttpClientDecorator.java:59) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.SessionedEurekaHttpClient.execute(SessionedEurekaHttpClient.java:77) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.DiscoveryClient.register(DiscoveryClient.java:876) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.InstanceInfoReplicator.run(InstanceInfoReplicator.java:121) [eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.InstanceInfoReplicator$1.run(InstanceInfoReplicator.java:101) [eureka-client-1.10.17.jar!/:1.10.17]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_322]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_322]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_322]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [na:1.8.0_322]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_322]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_322]
    at java.lang.Thread.run(Thread.java:750) [na:1.8.0_322]

2022-05-12 17:18:18.657  WARN 1 --- [nfoReplicator-0] c.n.discovery.InstanceInfoReplicator     : There was a problem with the instance info replicator

com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server
    at com.netflix.discovery.shared.transport.decorator.RetryableEurekaHttpClient.execute(RetryableEurekaHttpClient.java:112) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$1.execute(EurekaHttpClientDecorator.java:59) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.SessionedEurekaHttpClient.execute(SessionedEurekaHttpClient.java:77) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.DiscoveryClient.register(DiscoveryClient.java:876) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.InstanceInfoReplicator.run(InstanceInfoReplicator.java:121) ~[eureka-client-1.10.17.jar!/:1.10.17]
    at com.netflix.discovery.InstanceInfoReplicator$1.run(InstanceInfoReplicator.java:101) [eureka-client-1.10.17.jar!/:1.10.17]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_322]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_322]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_322]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [na:1.8.0_322]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_322]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_322]
    at java.lang.Thread.run(Thread.java:750) [na:1.8.0_322]

2022-05-12 17:18:18.727  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 5161 (https) with context path ''
2022-05-12 17:18:18.729  INFO 1 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 5161
2022-05-12 17:18:18.754  INFO 1 --- [           main] c.h.o.servidor.ConfigServerApplication   : Started ConfigServerApplication in 7.26 seconds (JVM running for 8.154)
2022-05-12 17:18:48.044  INFO 1 --- [tbeatExecutor-0] c.n.d.s.t.d.RedirectingEurekaHttpClient  : Request execution error. endpoint=DefaultEndpoint{ serviceUrl='http://{HOST_IP}:5160/eureka/}, exception=Could not extract response: no suitable HttpMessageConverter found for response type [class com.netflix.appinfo.InstanceInfo] and content type [text/plain;charset=UTF-8] stacktrace=org.springframework.web.client.UnknownContentTypeException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.netflix.appinfo.InstanceInfo] and content type [text/plain;charset=UTF-8]
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:126)
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:1037)
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:1020)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:778)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:711)
    at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:602)
    at org.springframework.cloud.netflix.eureka.http.RestTemplateEurekaHttpClient.sendHeartBeat(RestTemplateEurekaHttpClient.java:99)
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$3.execute(EurekaHttpClientDecorator.java:92)
    at com.netflix.discovery.shared.transport.decorator.RedirectingEurekaHttpClient.executeOnNewServer(RedirectingEurekaHttpClient.java:121)
    at com.netflix.discovery.shared.transport.decorator.RedirectingEurekaHttpClient.execute(RedirectingEurekaHttpClient.java:80)
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.sendHeartBeat(EurekaHttpClientDecorator.java:89)
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$3.execute(EurekaHttpClientDecorator.java:92)
    at com.netflix.discovery.shared.transport.decorator.RetryableEurekaHttpClient.execute(RetryableEurekaHttpClient.java:120)
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.sendHeartBeat(EurekaHttpClientDecorator.java:89)
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$3.execute(EurekaHttpClientDecorator.java:92)
    at com.netflix.discovery.shared.transport.decorator.SessionedEurekaHttpClient.execute(SessionedEurekaHttpClient.java:77)
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.sendHeartBeat(EurekaHttpClientDecorator.java:89)
    at com.netflix.discovery.DiscoveryClient.renew(DiscoveryClient.java:893)
    at com.netflix.discovery.DiscoveryClient$HeartbeatThread.run(DiscoveryClient.java:1457)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:750)

2022-05-12 17:18:48.044  WARN 1 --- [tbeatExecutor-0] c.n.d.s.t.d.RetryableEurekaHttpClient    : Request execution failed with message: Could not extract response: no suitable HttpMessageConverter found for response type [class com.netflix.appinfo.InstanceInfo] and content type [text/plain;charset=UTF-8]
2022-05-12 17:18:48.047 ERROR 1 --- [tbeatExecutor-0] com.netflix.discovery.DiscoveryClient    : DiscoveryClient_CLIENT-APP/6d68d6b84f02:CLIENT-APP:5161 - was unable to send heartbeat!

Note that I've changed the host ip for a pleceholder, but the other stuff is exact the error, the error replicates and keeps looping, as I told, server-app woks perfectly, client-app works perfectly, but it's not registering on the eureka server (server-app)

What I've done:

• Register in the same network
• User prefer-ip-address on true and false
• Work with and without eureka.instance.hostname
• Work with eureka.client.register-with-eureka on false (No errors, but I need to register the client-app, then this config has no point)
• I've deployed first server-app and then client-app
• Updated eureka server and client versions
• Use same version on server and client of Java, Maven, Springboot and Eureka
• User @EnableEurekaClient of @EnableDiscoveryClient

And that's it, I hope you can help me!

Thak all of you.