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::servicedirectory_v1::LookupServiceClient(
google::cloud::servicedirectory_v1::MakeLookupServiceConnection(
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 document provides guidance on overriding default authentication credentials when interacting with Google Cloud Services."],["The document highlights the use of `UnifiedCredentialsOption` to explicitly load a service account key file for authentication."],["Client libraries typically use Application Default Credentials, but this can be overridden using service account credentials."],["Examples for overriding credentials are provided for `servicedirectory_v1::LookupServiceClient` and `servicedirectory_v1::RegistrationServiceClient` classes."],["The document offers links to documentation on Authentication Components and Best practices for managing service account keys."]]],[]]
