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 page provides documentation for overriding default authentication credentials in Google Cloud C++ client libraries, starting with version 2.17.0 and listing versions up to 2.37.0-rc."],["Client libraries typically use Application Default Credentials, but you can override this by employing the `UnifiedCredentialsOption` with service account key files or other authentication methods."],["The example provided demonstrates how to load a service account key file to explicitly set authentication credentials using `google::cloud::MakeServiceAccountCredentials`."],["Specific examples are available for `logging_v2::ConfigServiceV2Client`, `logging_v2::LoggingServiceV2Client`, and `logging_v2::MetricsServiceV2Client` demonstrating how to handle service accounts."],["For further information on managing service account keys and creating `google::cloud::Credentials` objects, consult the best practices guide and the authentication components section, respectively."]]],[]]
