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 2025-04-09 UTC."],[[["The latest release candidate version is 2.37.0-rc, with multiple previous versions, ranging from 2.36.0 down to 2.11.0, also available for review."],["By default, client libraries use Application Default Credentials for Google Cloud Services authentication, but this can be overridden if needed."],["You can override default credentials by providing the UnifiedCredentialsOption, such as loading a service account key file."],["The provided code example demonstrates how to explicitly load a service account key file for authentication using `UnifiedCredentialsOption`."],["For further details on creating Credentials objects and best practices for managing service account keys, users can refer to the \"Authentication Components\" and \"Best practices for managing service account keys\" documentation links."]]],[]]
