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 service."],["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 release."],["The example provided demonstrates how to explicitly load a service account key file using `UnifiedCredentialsOption` and `MakeServiceAccountCredentials` for authentication."],["Links to examples for overriding authentication in other client classes such as `servicecontrol_v1::QuotaControllerClient` and `servicecontrol_v1::ServiceControllerClient` and `servicecontrol_v2::ServiceControllerClient` are also provided."],["The page references the \"Best practices for managing service account keys\" guide and the \"Authentication Components\" documentation for further details on service account authentication."]]],[]]