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 version-specific documentation for overriding authentication in the C++ client library, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["The client libraries use Application Default Credentials by default, but these can be overridden using the `UnifiedCredentialsOption` for specific cases."],["A service account key file can be explicitly loaded to override the default authentication method, as demonstrated in the example code provided."],["The provided example uses a service account key file, it should be noted that it is chosen for its simplicity and readers should consult best practices when managing service account keys."],["Further information on creating `google::cloud::Credentials` objects can be found in the Authentication Components section."]]],[]]
