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."],[[["The latest release candidate version is 2.37.0-rc, and the current version displayed on the page is 2.35.0, with several previous versions accessible."],["Client libraries use Application Default Credentials by default for Google Cloud Services, but this can be overridden using `UnifiedCredentialsOption`."],["You can load a service account key file explicitly by setting `google::cloud::UnifiedCredentialsOption` with service account credentials."],["The page provides examples on how to override authentication credentials for `servicecontrol_v1::QuotaControllerClient`, `servicecontrol_v1::ServiceControllerClient`, and `servicecontrol_v2::ServiceControllerClient`."],["The page directs you to further resources for authentication components and best practices for managing service account keys."]]],[]]
