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 release candidate version is 2.37.0-rc, with multiple previous versions ranging down to 2.11.0 available."],["Client libraries primarily use Application Default Credentials for authentication with Google Cloud Services unless otherwise configured."],["Users can override default credentials by providing the UnifiedCredentialsOption, as shown in the example of loading a service account key file."],["The provided example demonstrates how to explicitly load a service account key file, but users should refer to the \"Best practices for managing service account keys\" guide for comprehensive information."],["For more details on creating `google::cloud::Credentials` objects, refer to the \"Authentication Components\" documentation."]]],[]]
