Unless otherwise configured, the client libraries use Application Default Credentials to authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing the UnifiedCredentialsOption The following example shows how to explicitly load a service account key file:
[](std::string const& keyfile) {
auto is = std::ifstream(keyfile);
is.exceptions(std::ios::badbit); // Minimal error handling in examples
auto contents = std::string(std::istreambuf_iterator<char>(is.rdbuf()), {});
auto options =
google::cloud::Options{}.set<google::cloud::UnifiedCredentialsOption>(
google::cloud::MakeServiceAccountCredentials(contents));
return google::cloud::gkemulticloud_v1::AttachedClustersClient(
google::cloud::gkemulticloud_v1::MakeAttachedClustersConnection(
"us-west1" /* regional service region */, options));
}
Follow these links to find examples for other *Client classes:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThe latest version available for gkemulticloud is 2.37.0-rc, and the page provides access to multiple historical versions, down to version 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eClient libraries typically use Application Default Credentials for authentication, but this can be overridden when needed.\u003c/p\u003e\n"],["\u003cp\u003eAuthentication credentials can be overridden by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e to explicitly load a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples are provided for how to override authentication for \u003ccode\u003eAttachedClustersClient\u003c/code\u003e, \u003ccode\u003eAwsClustersClient\u003c/code\u003e, and \u003ccode\u003eAzureClustersClient\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe proper use of service account keys is important, so it's recommended to consult the guide for best practices, and to look into Authentication Components.\u003c/p\u003e\n"]]],[],null,[]]
