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"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, specifically focusing on the \u003ccode\u003egkemulticloud\u003c/code\u003e service.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically use Application Default Credentials, but users can override this by providing a \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as demonstrated with loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples for overriding authentication are available for \u003ccode\u003eAttachedClustersClient\u003c/code\u003e, \u003ccode\u003eAwsClustersClient\u003c/code\u003e, and \u003ccode\u003eAzureClustersClient\u003c/code\u003e classes within the \u003ccode\u003egkemulticloud_v1\u003c/code\u003e namespace.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version documented is 2.37.0-rc, and prior versions are also accessible, with the current default version being 2.32.0.\u003c/p\u003e\n"],["\u003cp\u003eThe best practices guide for managing service account keys is recommended for further details, and additional information on authentication components is provided via a link.\u003c/p\u003e\n"]]],[],null,[]]
