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::backupdr_v1::BackupDRClient(
google::cloud::backupdr_v1::MakeBackupDRConnection(options));
}
[[["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 2025-04-17 UTC."],[[["The latest release candidate version is 2.37.0-rc, with version 2.28.0 being the main page version."],["The client libraries primarily use Application Default Credentials for Google Cloud service authentication, but this can be overridden."],["Authentication credentials can be overridden by providing the UnifiedCredentialsOption."],["A service account key file can be explicitly loaded to override default credentials, as demonstrated in the provided code example."],["The Authentication Components documentation section provides information on factory functions for creating `google::cloud::Credentials` objects."]]],[]]
