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, and the content provides documentation for multiple versions of the Storage Transfer service, ranging from 2.11.0 to 2.37.0-rc."],["The client libraries typically use Application Default Credentials for authentication with Google Cloud Services, but this can be overridden."],["Overriding default authentication can be accomplished by providing the UnifiedCredentialsOption, for example, to explicitly load a service account key file."],["For more information on creating `google::cloud::Credentials` objects, refer to the Authentication Components documentation."],["The provided example demonstrates loading a service account key file to override default authentication, and users should refer to the \"Best practices for managing service account keys\" guide for additional details."]]],[]]
