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::resourcemanager_v3::FoldersClient(
google::cloud::resourcemanager_v3::MakeFoldersConnection(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 details how to override the default authentication credentials used by the client libraries when interacting with Google Cloud Services, which typically rely on Application Default Credentials."],["You can override the default credentials by providing the `UnifiedCredentialsOption`, as demonstrated in the example that shows how to load a service account key file."],["Versioned documentation is available from 2.11.0 to the latest release candidate 2.37.0-rc, where you may find the most relevant information depending on your version."],["Examples for overriding authentication are available for various client classes, including `FoldersClient`, `OrganizationsClient`, `ProjectsClient`, and several others, all of which are linked in this document."],["The page directs users to refer to the \"Best practices for managing service account keys\" guide and the \"Authentication Components\" section for further details on handling service account credentials and creating `google::cloud::Credentials` objects."]]],[]]
