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::datafusion_v1::DataFusionClient(
google::cloud::datafusion_v1::MakeDataFusionConnection(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 2025-03-05 UTC."],[[["This page provides documentation for overriding default authentication credentials when interacting with Google Cloud Services."],["The latest release candidate version is 2.37.0-rc, with a comprehensive list of previous versions from 2.36.0 down to 2.13.0 provided."],["Overriding authentication is done using the `UnifiedCredentialsOption`, which allows you to explicitly load a service account key file."],["The page includes an example demonstrating how to load a service account key file and use it for authentication, highlighting that this example is for simplicity."],["For a more in-depth look at creating `google::cloud::Credentials` objects, there is a link provided to the \"Authentication Components\" guide."]]],[]]