How can I get a Kubernetes authentication token from AWS EKS using the AWS Java SDK v2? An authentication token that can then be used to authenticate with Kubernetes using a Kubernetes SDK. In other words I want to get an authentication token from EKS to use for authentication with Kubernetes so that I don't have to create a "kube config".

I actually got a solution working with AWS Java SDK v1 (not v2) looking at the code examples in the following open issue. There is also a Python code example here BUT I'm not having any success with AWS Java SDK v2. My attempt at doing it with AWS Java SDK v2:

public static String getAuthenticationToken(AwsCredentialsProvider awsAuth, Region awsRegion, String clusterName) {
    try {
        SdkHttpFullRequest requestToSign = SdkHttpFullRequest
                .builder()
                .method(SdkHttpMethod.GET)
                .uri(new URI("https", String.format("sts.%s.amazonaws.com", awsRegion.id()), null, null))
                .appendHeader("x-k8s-aws-id", clusterName)
                .appendRawQueryParameter("Action", "GetCallerIdentity")
                .appendRawQueryParameter("Version", "2011-06-15")
                .build();

        ZonedDateTime expirationDate = DateUtil.addSeconds(DateUtil.now(), 60);
        Aws4PresignerParams presignerParams = Aws4PresignerParams.builder()
                .awsCredentials(awsAuth.resolveCredentials())
                .expirationTime(expirationDate.toInstant())
                .signingName("sts")
                .signingRegion(awsRegion)
                .build();

        SdkHttpFullRequest signedRequest = Aws4Signer.create().presign(requestToSign, presignerParams);

        String encodedUrl = Base64.getUrlEncoder().withoutPadding().encodeToString(signedRequest.getUri().toString().getBytes(CharSet.UTF_8.getCharset()));
        return ("k8s-aws-v1." + encodedUrl);
    } catch (Exception e) {
        String errorMessage = "A problem occurred generating an Eks token";
        logger.error(errorMessage, e);
        throw new RuntimeException(errorMessage, e);
    }
}

It generates a token, but when I use the token in my Kubernetes client (the official Java Kubernetes SDK) I get back an "Unauthorized" response - so I'm missing something I can't put my finger on...

The AWS Java SDK v1 version looks something like this: (From the open issue mentioned earlier)

I got it working, but I'm struggling to get something similar to work in AWS Java SDK v2.

private String generateToken(String clusterName,
                                 Date expirationDate,
                                 String serviceName,
                                 String region,
                                 AWSSecurityTokenServiceClient awsSecurityTokenServiceClient,
                                 AWSCredentialsProvider credentialsProvider,
                                 String scheme,
                                 String host) throws URISyntaxException {
        try {
            DefaultRequest<GetCallerIdentityRequest> callerIdentityRequestDefaultRequest = new DefaultRequest<>(new GetCallerIdentityRequest(), serviceName);
            URI uri = new URI(scheme, host, null, null);
            callerIdentityRequestDefaultRequest.setResourcePath("/");
            callerIdentityRequestDefaultRequest.setEndpoint(uri);
            callerIdentityRequestDefaultRequest.setHttpMethod(HttpMethodName.GET);
            callerIdentityRequestDefaultRequest.addParameter("Action", "GetCallerIdentity");
            callerIdentityRequestDefaultRequest.addParameter("Version", "2011-06-15");
            callerIdentityRequestDefaultRequest.addHeader("x-k8s-aws-id", clusterName);

            Signer signer = SignerFactory.createSigner(SignerFactory.VERSION_FOUR_SIGNER, new SignerParams(serviceName, region));
            SignerProvider signerProvider = new DefaultSignerProvider(awsSecurityTokenServiceClient, signer);
            PresignerParams presignerParams = new PresignerParams(uri,
                    credentialsProvider,
                    signerProvider,
                    SdkClock.STANDARD);

            PresignerFacade presignerFacade = new PresignerFacade(presignerParams);
            URL url = presignerFacade.presign(callerIdentityRequestDefaultRequest, expirationDate);
            String encodedUrl = Base64.getUrlEncoder().withoutPadding().encodeToString(url.toString().getBytes());
            log.info("Token [{}]", encodedUrl);
            return "k8s-aws-v1." + encodedUrl;
        } catch (URISyntaxException e) {
            log.error("could not generate token", e);
            throw e;
        }
    }