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::serviceusage_v1::ServiceUsageClient(
google::cloud::serviceusage_v1::MakeServiceUsageConnection(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 various versions of the Service Usage C++ client library, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["The client libraries typically use Application Default Credentials for authentication, but these defaults can be overridden when needed."],["You can override the default authentication by utilizing the UnifiedCredentialsOption and providing service account credentials, such as by loading a service account key file, as shown in the example."],["The provided example showcases a method to load credentials from a service account key file, but there are many other ways, and you should consult the best practices guide for managing service account keys for more information."],["The linked \"Authentication Components\" section can be used for more information regarding the factory functions to create `google::cloud::Credentials` objects."]]],[]]
