Unable to push images to a docker registry started in test containers

[sainsaji]

I'm trying to push images to a registry started in the testcontainers. I'm using java docker api to push images, tried manually as well, but I'm getting the same error.
The first test case will check if the repository is running and it works, it's the second test that fails.
I'm also able to fetch the catalogue from the repository using curl.

curl http://localhost:57025/v2/_catalog
{"repositories":[]}

Here is how you can replicate the issue.

class DockerRegistryTest {
    @Rule
    public static GenericContainer registry;
    private static String registryAddress;
    private static String registryHost;
    private static int PORT = 5000;

    private static DockerClient dockerClient;
    @BeforeAll
    static void startRegistry() {
        System.setProperty("com.github.dockerjava.insecure", "true");
        registry = new GenericContainer(DockerImageName.parse("registry:2"))
                .withPrivilegedMode(true)
                .withExposedPorts(PORT);
        registry.start();
        registryHost = registry.getHost();
        assertTrue(registry.isRunning(), "Registry is running");
        System.out.println(registry.getFirstMappedPort());
        registryAddress = registryHost + ":" + registry.getMappedPort(PORT);


        DockerClientConfig config = DefaultDockerClientConfig.createDefaultConfigBuilder()
                .withRegistryUrl(registryAddress).build();
        dockerClient = DockerClientImpl.getInstance(config, new ApacheDockerHttpClient.Builder()
                .dockerHost(config.getDockerHost())
                .sslConfig(null)
                .build());
    }

    @AfterAll
    static void tearDown() {
        if (registry != null) {
            registry.stop();
        }
    }

    @Test
    void testRegistryIsRunning() {
        assertTrue(registry.isRunning(), "Registry is running");
        System.out.println("Docker registry available at: " + registry.getHost() + ":" + registry.getMappedPort(PORT));
    }

    @Test
    void testPushImageToRegistry() throws InterruptedException {
        if (!registry.isRunning()) {
            registry.start();
        }

        String localImage = "busybox:latest";
        dockerClient.pullImageCmd(localImage).start().awaitCompletion();


        String registryImageTag = registryAddress + "/busybox:latest";
        dockerClient.tagImageCmd(localImage, registryAddress + "/busybox", "latest").exec();


        dockerClient.pushImageCmd(registryImageTag)
                .withAuthConfig(new AuthConfig())
                .start()
                .awaitCompletion();

        System.out.println("Successfully pushed image to registry: " + registryImageTag);
        assertTrue(true);
    }
} 

when I run this I get the error

com.github.dockerjava.api.exception.DockerClientException: Could not push image: failed to do request: Head "https://localhost:57244/v2/busybox/blobs/sha256:31311c5853a22c04d692f6581b4faa25771d915c1ba056c74e5ec82606eefdfa": dial tcp [::1]:57244: connect: connection refused

I tried changing the host to
0.0.0.0 , the I get a different error

com.github.dockerjava.api.exception.DockerClientException: Could not push image: failed to do request: Head "https://0.0.0.0:60075/v2/busybox/blobs/sha256:9c0abc9c5bd3a7854141800ba1f4a227baa88b11b49d8207eadc483c3f2496de": http: server gave HTTP response to HTTPS client