How to retrieve EKS services programatically?

Question

I'm trying to get the list of services from EKS using Spring boot and Kotlin. I was able to make it work with the following using fabric8:

@Configuration
class AwsConfig {
  @Bean
  fun kubernetesClient(): KubernetesClient {
    return KubernetesClientBuilder()
      .withConfig(
        ConfigBuilder()
          .withMasterUrl("master-url")
          .withOauthToken(
            "hard-coded-oauth-token"
          )
          .withTrustCerts()
          .build(),
      )
      .build()


  }
}

and then:

@Service
class EksService(val kubernetesClient: KubernetesClient) {
  fun getServices() {
    val services = kubernetesClient.services().list()
    println(services)

  }
}

I generated the "hard-coded-oauth-token" via cli command: aws eks get-token --cluster-name <cluster-name>

I'm trying to figure out how I can generate this oauth token progrematically, I couldn't find any documentation on that

Answer 1

I finally figured it out, with the help of this answer: https://stackoverflow.com/a/60204304

The code is in kotlin:

@Configuration
class AwsConfig {
  @Bean
  fun kubernetesClient(): KubernetesClient {
    return KubernetesClientBuilder()
      .withConfig(
        ConfigBuilder()
          .withMasterUrl("https://<clusterId>.<region>.eks.amazonaws.com")
          .withTrustCerts()
          .withOauthTokenProvider { getToken() }
          .build(),
      )
      .build()
  }

  fun getToken(): String {
    val stsUri = URI("https", "sts.${<region>}.amazonaws.com", "/", null)
    val requestToSign = SdkHttpFullRequest
      .builder()
      .method(SdkHttpMethod.GET)
      .uri(stsUri)
      .appendHeader("x-k8s-aws-id", "<cluster_name>")
      .appendRawQueryParameter("Action", "GetCallerIdentity")
      .appendRawQueryParameter("Version", "2011-06-15")
      .build()

    val presignerParams = Aws4PresignerParams.builder()
      .awsCredentials(
        AwsSessionCredentials.create(.....),
      )
      .signingRegion(EU_CENTRAL_1)
      .signingName("sts")
      .signingClockOverride(Clock.systemUTC())
      .expirationTime(Instant.now().plus(60, ChronoUnit.SECONDS))
      .build()

    val signedRequest = Aws4Signer.create().presign(requestToSign, presignerParams)

    val encodedUrl: String = Base64.getUrlEncoder().withoutPadding().encodeToString(
      signedRequest.uri.toString().toByteArray(),
    )
    return ("k8s-aws-v1.$encodedUrl")
  }