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::gkebackup_v1::BackupForGKEClient(
google::cloud::gkebackup_v1::MakeBackupForGKEConnection(options));
}
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 various versions of the \u003ccode\u003egkebackup\u003c/code\u003e library, ranging from version 2.12.0 up to the latest release candidate, 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe default authentication for the client libraries uses Application Default Credentials, but you can override this by providing the UnifiedCredentialsOption.\u003c/p\u003e\n"],["\u003cp\u003eOverriding the default authentication can be achieved by loading a service account key file, as demonstrated in the provided example using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe provided example demonstrates overriding the default credentials by reading a service account key file and using \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e and \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eFor more details on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects and factory functions, refer to the Authentication Components section.\u003c/p\u003e\n"]]],[],null,[]]
