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 2025-04-02 UTC."],[[["This webpage provides a list of available versions for the Storage Transfer service, ranging from the latest release candidate, version 2.37.0-rc, down to version 2.11.0."],["The default authentication for client libraries uses Application Default Credentials, but these can be overridden when necessary."],["Overriding the default authentication can be done by setting the `UnifiedCredentialsOption`, with an example provided that shows how to load a service account key file."],["For best practices on managing service account keys, it's recommended to consult the linked guide."],["Additional information on creating `google::cloud::Credentials` objects can be found in the \"Authentication Components\" section linked on this page."]]],[]]