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 2025-03-21 UTC."],[[["This webpage provides documentation for overriding default authentication credentials when interacting with Google Cloud Services."],["The most current version of the documentation is for version 2.37.0-rc, with a full listing available back to version 2.13.0."],["Authentication is typically handled by Application Default Credentials, but users can override this by utilizing the `UnifiedCredentialsOption`."],["A service account key file can be used to override default credentials by using the `MakeServiceAccountCredentials` function."],["The page contains links to the general documentation for Authentication Components and best practices for managing service account keys for further reading."]]],[]]
