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::datacatalog_lineage_v1::LineageClient(
google::cloud::datacatalog_lineage_v1::MakeLineageConnection(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 C++ client libraries, specifically within the Data Catalog service."],["The latest release candidate version is 2.37.0-rc, and there are multiple prior versions of the Data Catalog documented on this page, going back to version 2.11.0."],["The default authentication mechanism uses Application Default Credentials, but can be overridden by using `UnifiedCredentialsOption`, and the page provides an example of loading a service account key file."],["Examples are provided for several `*Client` classes, including `datacatalog_lineage_v1::LineageClient`, `datacatalog_v1::DataCatalogClient`, `datacatalog_v1::PolicyTagManagerClient`, and `datacatalog_v1::PolicyTagManagerSerializationClient`."],["The \"See Also\" section provides a link to the \"Authentication Components\" guide, which contains factory functions for creating `google::cloud::Credentials` objects, and also references best practices for managing service account keys."]]],[]]
