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::ExperimentalTag{},
google::cloud::datacatalog_lineage_v1::MakeLineageConnection(
google::cloud::ExperimentalTag{}, 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 2025-03-21 UTC."],[[["This document provides guidance on overriding default authentication credentials when interacting with Google Cloud Services, particularly within the context of C++ client libraries for Data Catalog."],["The latest available version is 2.37.0-rc, and there is a list of previous versions that ranges from 2.36.0 down to version 2.11.0, with the ability to view documentation for each."],["The `UnifiedCredentialsOption` class allows you to override the default credentials, as demonstrated by loading a service account key file, allowing users to manage their own authentication method."],["Examples are provided for several client classes, including `datacatalog_lineage_v1::LineageClient`, `datacatalog_v1::DataCatalogClient`, `datacatalog_v1::PolicyTagManagerClient`, and `datacatalog_v1::PolicyTagManagerSerializationClient`, demonstrating how to apply this credential override."],["Users can refer to the \"Authentication Components\" section for information on creating `google::cloud::Credentials` objects, and \"Best practices for managing service account keys\" for more details regarding service accounts."]]],[]]
