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::servicecontrol_v1::QuotaControllerClient(
google::cloud::servicecontrol_v1::MakeQuotaControllerConnection(
options));
}
Follow these links to find examples for other *Client classes:
[[["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."],[[["The latest version of the service control documentation is 2.37.0-rc, with many prior versions available, ranging down to version 2.11.0."],["By default, the client libraries use Application Default Credentials for authentication with Google Cloud Services, but this can be overridden."],["Authentication can be overridden by utilizing the `UnifiedCredentialsOption`, as demonstrated by the example code showing how to load a service account key file."],["The documentation provides examples for overriding authentication in `servicecontrol_v1::QuotaControllerClient`, `servicecontrol_v1::ServiceControllerClient`, and `servicecontrol_v2::ServiceControllerClient` classes."],["The documentation links to additional information regarding `Authentication Components` and `Best practices for managing service account keys`."]]],[]]
