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."],[[["The latest version of the Storage Transfer C++ client library is 2.37.0-rc, with a variety of previous versions available, ranging from 2.36.0 down to 2.11.0."],["The client libraries use Application Default Credentials for authentication with Google Cloud Services unless explicitly configured."],["You can override the default authentication by providing a `UnifiedCredentialsOption`, such as loading a service account key file using the provided example code."],["The example provided shows how to explicitly load a service account key file, but it is suggested to consult the guide for best practices for managing these keys."],["For further information on creating `google::cloud::Credentials` objects, you can refer to the Authentication Components documentation."]]],[]]
