[Bug]: Two custom containers can't connect on docker using testcontainers

[dbraun1991]

Module

Core

Testcontainers version

1.19.8

Using the latest Testcontainers version?

Yes

Host OS

MacOS

Host Arch

ARM

Docker version

Client:
 Cloud integration: v1.0.35+desktop.13
 Version:           26.1.1
 API version:       1.45
 Go version:        go1.21.9
 Git commit:        4cf5afa
 Built:             Tue Apr 30 11:44:56 2024
 OS/Arch:           darwin/arm64
 Context:           desktop-linux

Server: Docker Desktop 4.30.0 (149282)
 Engine:
  Version:          26.1.1
  API version:      1.45 (minimum version 1.24)
  Go version:       go1.21.9
  Git commit:       ac2de55
  Built:            Tue Apr 30 11:48:04 2024
  OS/Arch:          linux/arm64
  Experimental:     false
 containerd:
  Version:          1.6.31
  GitCommit:        e377cd56a71523140ca6ae87e30244719194a521
 runc:
  Version:          1.1.12
  GitCommit:        v1.1.12-0-g51d5e94
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

What happened?

=== First ===
Java code from the testcontainers library behaves differently.

• MacOS on "MacBook Pro from 2023" with "Apple M2 Pro Silicon" fails
• Gitlab Pipeline with linux runner executes successfully

=== Second ===
The bookingEndpoint gets an IP that is not sufficient for connecting.
Neither of the following ...

• http://localhost:Port (obviously wrong)
• http://authEndpoint:Port (not rerouted by docker)
• http://HostIpAddress:Port (Given IP not leading to the authEndpoint)
  ... leads to a connection.
  Needed solution for:
  bookingEndpoint.withEnv("AUTH_URL", authEndpointBaseURL);

=== Third ===
Executing the JARs without Testcontainers locally -> works as a charm, just as in gitlab pipeline

`
// Static definitions which are lifted before all tests

// Define the NATS & MySql
@ClassRule
public static GenericContainer<?> natsContainer =
        new GenericContainer<>(
                DockerImageName.parse("nats:alpine3.19"))
                .withExposedPorts(4222) // Default MQTT port
                .withNetwork(network)
                .withNetworkAliases("natsmb")
                .waitingFor(Wait.forListeningPort());

@ClassRule
public static MySQLContainer<?> mysqlContainer =
        new MySQLContainer<>("mysql:8.2")
                .withDatabaseName("testdb")
                .withUsername("test")
                .withPassword("test")
                // Adjust the service network
                .withNetwork(network)
                .withNetworkAliases("mysqldb");

// Define the container for the AuthEndpoint using the built image
@ClassRule
public static GenericContainer<?> authEndpoint =
        new GenericContainer<>(authEndpointDockerImage)
                .withExposedPorts(authEndpointPort)
                // Adjust the service network
                .withNetwork(network)
                .withNetworkAliases("authEndpoint")

                // Adjust the 'infrastructure'-connections
                .withEnv("DB_URL", "jdbc:mysql://mysqldb:3306/testdb")
                .withEnv("DB_USERNAME", "test")
                .withEnv("DB_PASSWORD", "test")
                .withEnv("NATS_URL", "nats://natsmb:4222")
                .withEnv("INSTANCE_INDICATOR", "AUTH")
                .withEnv("INITIAL_DELAY", "130000")
                .withEnv("FIXED_INTERVAL", "12000000")

                // Add a wait strategy for the AuthEndpoint, ensuring the mysqlContainer is up first
                .dependsOn(mysqlContainer, mysqlContainer)
                // AuthEndpoint is ready => actuator is open for connection:
                .waitingFor(Wait.forHttp("/actuator").forStatusCode(200));

// Define the container for BookingEndpoint using the built image
@ClassRule
public static GenericContainer<?> bookingEndpoint =
        new GenericContainer<>(bookingEndpointDockerImage)
                .withExposedPorts(bookingEndpointPort)
                // Adjust the service network
                .withNetwork(network)
                .withNetworkAliases("bookingEndpoint")

                // Adjust the 'infrastructure'-connections
                .withEnv("DB_URL", "jdbc:mysql://mysqldb:3306/testdb")
                .withEnv("DB_USERNAME", "test")
                .withEnv("DB_PASSWORD", "test")
                .withEnv("NATS_URL", "nats://natsmb:4222")
                .withEnv("INSTANCE_INDICATOR", "BOOKING")
                .withEnv("AUTH_URL", "")
                .withEnv("INITIAL_DELAY", "1000")
                .withEnv("FIXED_INTERVAL", "5000")

                // Add a wait strategy for the BookingEndpoint, ensuring the AuthEndpoint is up first
                .dependsOn(authEndpoint)
                // BookingEndpoint is ready => actuator is open for connection:
                .waitingFor(Wait.forHttp("/actuator").forStatusCode(200));


static {
    OffsetDateTime start = OffsetDateTime.now();
    logger.info(String.format("Setup start at: %s", start));

    logger.info("==============================================");
    logger.info("=====     Starting the message broker    =====");
    logger.info("==============================================");
    // Start the message broker
    natsContainer.start();
    // === Set system properties ===
    // --> MessageQueue
    String natsURL = String.format("nats://%s:%s",
            natsContainer.getHost(),
            natsContainer.getMappedPort(4222));
    System.setProperty("NATS_URL", natsURL);

    // Start the database
    logger.info("==============================================");
    logger.info("=====        Starting the database       =====");
    logger.info("==============================================");
    mysqlContainer.start();
    // === Set system properties ===
    // --> Database
    System.setProperty("DB_URL", mysqlContainer.getJdbcUrl());
    System.setProperty("DB_USERNAME", mysqlContainer.getUsername());
    System.setProperty("DB_PASSWORD", mysqlContainer.getPassword());

    // Start the AuthEndpoint
    logger.info("==============================================");
    logger.info("=====     Starting the Auth-Endpoint     =====");
    logger.info("==============================================");
    authEndpoint.start();
    authEndpointBaseURL =
            "http://" + getHostIp(authEndpoint) + ":" + authEndpoint.getMappedPort(authEndpointPort);
    // authEndpointBaseURL2 = "http://authEndpoint:" + authEndpoint.getMappedPort(authEndpointPort);

    bookingEndpoint.withEnv("AUTH_URL", authEndpointBaseURL);
    logger.info("AuthUrl given to BookingEndpoint definition via ENV:   " + authEndpointBaseURL);

    bookingEndpoint.start();

    // === Set general system properties ===
    System.setProperty("INSTANCE_INDICATOR", "VALIDATOR");

    Duration duration = Duration.between(start, OffsetDateTime.now());
    logger.info(String.format("Setup took %s seconds", duration.getSeconds()));

    // Known startup duration is ~30 seconds locally and ~60 seconds in pipeline.
    // It shall be known if Environment startup-time drastically changes.
    // assertTrue(duration.getSeconds() < 90);
}

private static String getHostIp(GenericContainer<?> authEndpoint) {

    if (authEndpoint.getHost().equals("localhost")) {
        try {
            // Get IP from Host-Machine 
            return InetAddress.getLocalHost().getHostAddress();
        } catch (UnknownHostException e) {
            throw new RuntimeException(e);
        }
    }
    return authEndpoint.getHost();
}

`

Relevant log output

Custom Log Output:

• I/O error on GET request for "http://RecentIP:TempPort/v1/publickey": null
• I/O error on GET request for "http://RecentIP:TempPort/actuator": null

Additional Information

https://stackoverflow.com/questions/78352477/testcontainers-container-gethost-is-behaving-differently-locally-vs-gitlab-pi