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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThe webpage provides documentation for Google Cloud's GKE Multi-Cloud C++ client library, showcasing multiple version releases from 2.11.0 to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eIt explains how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eA practical example demonstrates explicitly loading a service account key file to create and set credentials, offering a method for managing authentication beyond default settings.\u003c/p\u003e\n"],["\u003cp\u003eLinks are provided for other Client classes, including \u003ccode\u003eAttachedClustersClient\u003c/code\u003e, \u003ccode\u003eAwsClustersClient\u003c/code\u003e, and \u003ccode\u003eAzureClustersClient\u003c/code\u003e, to show how the service account can be implemented in other situations.\u003c/p\u003e\n"],["\u003cp\u003eThe document advises consulting the "Best practices for managing service account keys" guide for further details and refers to "Authentication Components" for additional information on creating \u003ccode\u003eCredentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
