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 2025-03-14 UTC."],[[["This page provides documentation for overriding default authentication credentials when using Google Cloud C++ client libraries, specifically within the context of the Dataproc Metastore service."],["The latest release candidate version is 2.37.0-rc, and the page lists numerous past versions, going as far back as version 2.13.0, each with its own set of documentation on authentication override."],["The page explains how to override the default Application Default Credentials (ADC) by using the `UnifiedCredentialsOption` and provides a code snippet demonstrating how to load a service account key file."],["Examples are available for both `metastore_v1::DataprocMetastoreClient` and `metastore_v1::DataprocMetastoreFederationClient`, with links provided to the corresponding code snippets."],["The documentation directs users to consult the \"Best practices for managing service account keys\" guide for further details on credential management and also refers to \"Authentication Components\" for details on creating `google::cloud::Credentials` objects."]]],[]]