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 2025-04-09 UTC."],[[["This page details how to override the default authentication credentials for Google Cloud client libraries, which typically use Application Default Credentials."],["You can override the default credentials by using the `UnifiedCredentialsOption`, as demonstrated through the process of loading a service account key file."],["The example demonstrates setting the `UnifiedCredentialsOption` using a service account key file, but the best practices for managing service accounts keys should be consulted for more details."],["There are examples for overriding authentication for specific clients, including `datacatalog_lineage_v1::LineageClient`, `datacatalog_v1::DataCatalogClient`, `datacatalog_v1::PolicyTagManagerClient`, and `datacatalog_v1::PolicyTagManagerSerializationClient`."],["The page provides a version history for the DataCatalog C++ documentation, ranging from version 2.11.0 to 2.37.0-rc (latest)."]]],[]]
