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::metastore_v1::DataprocMetastoreClient(
google::cloud::metastore_v1::MakeDataprocMetastoreConnection(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 2025-04-17 UTC."],[[["This page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, specifically for the Metastore service."],["The client libraries typically use Application Default Credentials for authentication, but users can override this by using the `UnifiedCredentialsOption` and providing a service account key file."],["The latest release candidate version for this service is 2.37.0-rc, with multiple older versions, all the way down to version 2.13.0, that are also available."],["Examples are available for `DataprocMetastoreClient` and `DataprocMetastoreFederationClient` to demonstrate how to override authentication using service account key files."],["Users can refer to the \"Best practices for managing service account keys\" guide and the \"Authentication Components\" section for more details on managing service account keys and creating `google::cloud::Credentials` objects."]]],[]]
