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."],[[["This document provides a reference for various versions of service control, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["The default authentication with Google Cloud Services utilizes Application Default Credentials, but they can be overridden as needed."],["Overriding default authentication can be accomplished by using the `UnifiedCredentialsOption`, such as loading a service account key file."],["Examples for different client classes, including `QuotaControllerClient` and `ServiceControllerClient` for both `servicecontrol_v1` and `servicecontrol_v2`, are available for reference."],["For detailed guidance on service account key management, the document suggests referring to the \"Best practices for managing service account keys\" guide."]]],[]]
