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 focusing on the `UnifiedCredentialsOption`."],["The latest release candidate version is 2.37.0-rc, and a range of other versions, from 2.36.0 down to 2.11.0, are also documented, all of which include instructions for overriding the authentication."],["The page demonstrates how to explicitly load a service account key file using the `UnifiedCredentialsOption` and the `MakeServiceAccountCredentials` function within the `google::cloud` namespace."],["Examples are available for different client classes like `QuotaControllerClient` and `ServiceControllerClient` within various `servicecontrol_v` namespaces, with links to each being provided on the webpage."],["Users are directed to the \"Best practices for managing service account keys\" guide for more in-depth details on service account key management and the \"Authentication Components\" page to better understand the `google::cloud::Credentials` objects."]]],[]]