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::logging_v2::ConfigServiceV2Client(
google::cloud::logging_v2::MakeConfigServiceV2Connection(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 a guide on how to override default authentication credentials when using Google Cloud Client Libraries, allowing the user to use service account keys."],["The latest version documented is 2.37.0-rc, with a comprehensive list of previous versions available, from 2.36.0 down to 2.11.0, for reference."],["The example code demonstrates overriding the default credentials by loading a service account key file via the `UnifiedCredentialsOption`, then applying it to the client."],["The documentation lists specific client classes (`logging_v2::ConfigServiceV2Client`, `logging_v2::LoggingServiceV2Client`, `logging_v2::MetricsServiceV2Client`) with links to examples on how to override the authentication for each."],["It is recommended to consult the \"Best practices for managing service account keys\" guide for more information, and to also read the Authentication Components documentation for more information on the factory functions to create credentials objects."]]],[]]
