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 2025-03-14 UTC."],[[["This page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, specifically for the Service Control API."],["The latest version documented is `2.37.0-rc`, and the content provides access to documentation for multiple versions, ranging from `2.11.0` up to the latest version, `2.37.0-rc`."],["Client libraries typically use Application Default Credentials, but this can be overridden by providing the `UnifiedCredentialsOption`, as shown in the provided example using a service account key file."],["The documentation includes examples for the `servicecontrol_v1::QuotaControllerClient`, `servicecontrol_v1::ServiceControllerClient`, and `servicecontrol_v2::ServiceControllerClient` classes, regarding service account authentication."],["Users can find more information on creating `google::cloud::Credentials` objects in the linked \"Authentication Components\" documentation and further details in the \"Best practices for managing service account keys\" guide."]]],[]]
