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::domains_v1::DomainsClient(
google::cloud::domains_v1::MakeDomainsConnection(options));
}
[[["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 2025-04-17 UTC."],[[["This page provides documentation for various versions of the C++ client library, ranging from version 2.12.0 to the latest release candidate 2.37.0-rc, for managing authentication in Google Cloud services."],["The client libraries typically utilize Application Default Credentials for authentication, but users can override these defaults when required."],["The process to override default authentication utilizes the `UnifiedCredentialsOption`, and a detailed example demonstrates explicitly loading credentials from a service account key file."],["Users are advised to refer to the provided guide on managing service account keys for best practices when overriding default authentication methods."],["Further information on creating `google::cloud::Credentials` objects can be found in the linked \"Authentication Components\" section."]]],[]]
