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::resourcesettings_v1::ResourceSettingsServiceClient(
google::cloud::resourcesettings_v1::
MakeResourceSettingsServiceConnection(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 2025-03-21 UTC."],[[["This document provides a reference for overriding authentication credentials in Google Cloud C++ client libraries, covering versions from 2.11.0 up to the latest release candidate 2.37.0-rc."],["By default, the client libraries utilize Application Default Credentials for authentication, but you can override this using the UnifiedCredentialsOption."],["The document demonstrates an example of overriding default credentials by explicitly loading a service account key file."],["Users should refer to the \"Best practices for managing service account keys\" guide for detailed information on managing credentials securely."],["The \"Authentication Components\" section provides further details on factory functions for creating `google::cloud::Credentials` objects."]]],[]]