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::functions_v1::CloudFunctionsServiceClient(
google::cloud::functions_v1::MakeCloudFunctionsServiceConnection(
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 2025-03-05 UTC."],[[["This page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, which typically rely on Application Default Credentials."],["The latest version documented here is 2.37.0-rc, and documentation exists for versions dating back to 2.11.0, providing a historical overview of the feature's implementation."],["Users can override the default authentication by using `UnifiedCredentialsOption` and providing a service account key file, with a provided example demonstrating how to load such a file."],["The page highlights the `functions_v1::CloudFunctionsServiceClient` and `functions_v2::FunctionServiceClient` classes as examples and provides links to service account snippets for them."],["Additional information and best practices for managing service account keys and authentication components are linked for further reference."]]],[]]
