Microservices communication with a spring gateway

Question

I'm very new in springboot and I'm trying to explore this world.

I was creating three microservices that communicates to each other. Everything seems working except the Spring gateway that I just added.

The API call returns:

Error: Socket hang up

This is the configuration that I made but for sure I think it is not 100% correct. Can You help me to discover the bad config?

This is the docker-compose:

version: '3.4'

x-common-variables: &common-variables
  DATASOURCE_USER: ${DB_USER}
  DATASOURCE_PASSWORD: ${DB_PASSWORD}
  DATASOURCE_PORT: ${DB_PORT}

services:
  apigateway:
    build:
      context: .
      dockerfile: APIgateway/Dockerfile
    ports:
      - "4444:4444"
    restart: always

  paymysqldb:
    container_name: paymysqldb
    image: mysql
    ports:
      - "3313:3306"
    environment:
      - MYSQL_DATABASE=${DB_DATABASE_PAY}
      - MYSQL_USER=${DB_USER}
      - MYSQL_PASSWORD=${DB_PASSWORD}
      - MYSQL_ROOT_PASSWORD=${DB_ROOT_PASSWORD}
    volumes:
      - paystorage:/var/lib/mysql


  usermysqldb:
    container_name: usermysqldb
    image: mysql
    ports:
      - "3311:3306"
    environment:
      - MYSQL_DATABASE=${DB_DATABASE_USER}
      - MYSQL_USER=${DB_USER}
      - MYSQL_PASSWORD=${DB_PASSWORD}
      - MYSQL_ROOT_PASSWORD=${DB_ROOT_PASSWORD}
    volumes:
      - userstorage:/var/lib/mysql

  catalogmysqldb:
    container_name: catalogmysqldb
    image: mysql
    ports:
      - "3312:3306"
    environment:
      - MYSQL_DATABASE=${DB_DATABASE_CATALOG}
      - MYSQL_USER=${DB_USER}
      - MYSQL_PASSWORD=${DB_PASSWORD}
      - MYSQL_ROOT_PASSWORD=${DB_ROOT_PASSWORD}
    volumes:
      - catalogstorage:/var/lib/mysql

  paymanager:
    container_name: paymanager
    image: arausa/payimage
    build:
      context: .
      dockerfile: MicroServices/PaymentManager/Dockerfile
    depends_on:
      - paymysqldb
    ports:
      - "3333:3333"
    restart: always
    environment:
      <<: *common-variables
      PM_DATASOURCE_HOST: ${DB_HOST_PAY}
      PM_DATASOURCE_NAME: ${DB_DATABASE_PAY}

  usermanager:
    container_name: usermanager
    image: arausa/userimage
    build:
      context: .
      dockerfile: MicroServices/UserManager/Dockerfile
    depends_on:
      - usermysqldb
    ports:
      - "1111:1111"
    restart: always
    environment:
      <<: *common-variables
      UM_DATASOURCE_HOST: ${DB_HOST_USER}
      UM_DATASOURCE_NAME: ${DB_DATABASE_USER}
    expose:
      - "1111"

  catalogmanager:
    container_name: catalogmanager
    image: arausa/catalogimage
    build:
      context: .
      dockerfile: MicroServices/CatalogManager/Dockerfile
    depends_on:
      - catalogmysqldb
    ports:
      - "2222:2222"
    restart: always
    environment:
      <<: *common-variables
      CM_DATASOURCE_HOST: ${DB_HOST_CATALOG}
      CM_DATASOURCE_NAME: ${DB_DATABASE_CATALOG}



#kafka usa zookeeper tiene traccia dei broker, topologia della network e info per la sincronizzazione
  zookeeper:
    image: wurstmeister/zookeeper

#identifica il broker kafka
  kafka:
    image: wurstmeister/kafka
    ports:
      - "9092:9092"  #porta di default per il broker kafka
    environment:
      KAFKA_ADVERTISED_HOST_NAME: kafka
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181  #serve a dire dove sta girando zookeeper


volumes:
  userstorage:
  catalogstorage:
  paystorage:

This is the API gateway class

package com.example.apigateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
@EnableDiscoveryClient
public class APIgatewayApplication {

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


    @Bean
    public RouteLocator myRoutes(RouteLocatorBuilder builder) {
        return builder.routes()
                .route(p -> p
                        .path("/user/**")
                        .uri("http://usermanager:1111"))
                .route(p -> p
                        .path("/catalog/**")
                        .uri("http://catalogmanager:2222"))
                .route(p -> p
                        .path("/payment/**")
                        .uri("http://paymanager:3333"))
                .build();
    }
}

This is the application.properties:

spring.application.name=apigateway
server.port=4444

And finally this is the .env even if I don't think it is usefull for this problem:

DB_DATABASE_PAY=PayDB
DB_HOST_PAY=paymysqldb

DB_DATABASE_USER=UserDB
DB_HOST_USER=usermysqldb

DB_DATABASE_CATALOG=CatalogDB
DB_HOST_CATALOG=catalogmysqldb


DB_USER=db_user
DB_PASSWORD=ale2022
DB_ROOT_PASSWORD=user
DB_PORT=3306

My bad. I forgot to recreate the image of the API.

The error is now :

500 Server Error for HTTP POST "/user/addUser"
apigateway_1      | 
apigateway_1      | io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: usermanager/172.18.0.10:1111