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 page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, with a focus on versions 2.11.0 through 2.37.0-rc."],["By default, client libraries utilize Application Default Credentials (ADC) for authenticating with Google Cloud Services, but this can be customized when necessary."],["The `UnifiedCredentialsOption` is the mechanism used to override the default credentials, allowing you to set credentials such as loading a service account key file."],["A code example is provided to illustrate how to load a service account key file to override the default credentials, although users are advised to consult best practices for managing service account keys."],["The \"See Also\" section links to more information on the factory functions for creating `google::cloud::Credentials` objects, providing further details on authentication components."]]],[]]
