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::storagetransfer_v1::StorageTransferServiceClient(
google::cloud::storagetransfer_v1::MakeStorageTransferServiceConnection(
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 2025-04-22 UTC."],[[["This page provides documentation for various versions of the Storage Transfer Service C++ client library, ranging from version 2.11.0 to the latest release candidate, 2.37.0-rc."],["The client libraries typically use Application Default Credentials for authentication, but they support overriding this default behavior when necessary."],["You can override the default authentication method by providing a UnifiedCredentialsOption, such as loading a service account key file explicitly, to the Storage Transfer Service client."],["The provided code example demonstrates how to load a service account key file to create a StorageTransferServiceClient with specific credentials."],["The Authentication Components guide offers further details on creating Credentials objects for use with Google Cloud services, if needed."]]],[]]
