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::dataplex_v1::CatalogServiceClient(
google::cloud::dataplex_v1::MakeCatalogServiceConnection(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"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, specifically within the context of the Dataplex service.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically rely on Application Default Credentials, but you can use \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e to override this, such as by loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eA list of client classes is provided, including \u003ccode\u003eCatalogServiceClient\u003c/code\u003e, \u003ccode\u003eContentServiceClient\u003c/code\u003e, \u003ccode\u003eDataScanServiceClient\u003c/code\u003e, \u003ccode\u003eDataTaxonomyServiceClient\u003c/code\u003e, \u003ccode\u003eDataplexServiceClient\u003c/code\u003e, and \u003ccode\u003eMetadataServiceClient\u003c/code\u003e, with links to examples of service account usage.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation covers Dataplex versions from 2.11.0 up to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe provided example demonstrates how to load a service account keyfile and create a \u003ccode\u003eCatalogServiceClient\u003c/code\u003e with the specified credentials.\u003c/p\u003e\n"]]],[],null,["Version 2.29.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/dataplex/latest/dataplex-override-authentication)\n- [2.41.0](/cpp/docs/reference/dataplex/2.41.0/dataplex-override-authentication)\n- [2.40.0](/cpp/docs/reference/dataplex/2.40.0/dataplex-override-authentication)\n- [2.39.0](/cpp/docs/reference/dataplex/2.39.0/dataplex-override-authentication)\n- [2.38.0](/cpp/docs/reference/dataplex/2.38.0/dataplex-override-authentication)\n- [2.37.0](/cpp/docs/reference/dataplex/2.37.0/dataplex-override-authentication)\n- [2.36.0](/cpp/docs/reference/dataplex/2.36.0/dataplex-override-authentication)\n- [2.35.0](/cpp/docs/reference/dataplex/2.35.0/dataplex-override-authentication)\n- [2.34.0](/cpp/docs/reference/dataplex/2.34.0/dataplex-override-authentication)\n- [2.33.0](/cpp/docs/reference/dataplex/2.33.0/dataplex-override-authentication)\n- [2.32.0](/cpp/docs/reference/dataplex/2.32.0/dataplex-override-authentication)\n- [2.31.0](/cpp/docs/reference/dataplex/2.31.0/dataplex-override-authentication)\n- [2.30.0](/cpp/docs/reference/dataplex/2.30.0/dataplex-override-authentication)\n- [2.29.0](/cpp/docs/reference/dataplex/2.29.0/dataplex-override-authentication)\n- [2.28.0](/cpp/docs/reference/dataplex/2.28.0/dataplex-override-authentication)\n- [2.27.0](/cpp/docs/reference/dataplex/2.27.0/dataplex-override-authentication)\n- [2.26.0](/cpp/docs/reference/dataplex/2.26.0/dataplex-override-authentication)\n- [2.25.1](/cpp/docs/reference/dataplex/2.25.1/dataplex-override-authentication)\n- [2.24.0](/cpp/docs/reference/dataplex/2.24.0/dataplex-override-authentication)\n- [2.23.0](/cpp/docs/reference/dataplex/2.23.0/dataplex-override-authentication)\n- [2.22.1](/cpp/docs/reference/dataplex/2.22.1/dataplex-override-authentication)\n- [2.21.0](/cpp/docs/reference/dataplex/2.21.0/dataplex-override-authentication)\n- [2.20.0](/cpp/docs/reference/dataplex/2.20.0/dataplex-override-authentication)\n- [2.19.0](/cpp/docs/reference/dataplex/2.19.0/dataplex-override-authentication)\n- [2.18.0](/cpp/docs/reference/dataplex/2.18.0/dataplex-override-authentication)\n- [2.17.0](/cpp/docs/reference/dataplex/2.17.0/dataplex-override-authentication)\n- [2.16.0](/cpp/docs/reference/dataplex/2.16.0/dataplex-override-authentication)\n- [2.15.1](/cpp/docs/reference/dataplex/2.15.1/dataplex-override-authentication)\n- [2.14.0](/cpp/docs/reference/dataplex/2.14.0/dataplex-override-authentication)\n- [2.13.0](/cpp/docs/reference/dataplex/2.13.0/dataplex-override-authentication)\n- [2.12.0](/cpp/docs/reference/dataplex/2.12.0/dataplex-override-authentication)\n- [2.11.0](/cpp/docs/reference/dataplex/2.11.0/dataplex-override-authentication) \n\nHow to Override the Authentication Credentials\n==============================================\n\nUnless otherwise configured, the client libraries use [Application Default Credentials](https://cloud.google.com/docs/authentication#adc) 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](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1UnifiedCredentialsOption.html) The following example shows how to explicitly load a service account key file: \n\n [](std::string const& keyfile) {\n auto is = std::ifstream(keyfile);\n is.exceptions(std::ios::badbit); // Minimal error handling in examples\n auto contents = std::string(std::istreambuf_iterator\u003cchar\u003e(is.rdbuf()), {});\n auto options =\n google::cloud::Options{}.set\u003cgoogle::cloud::UnifiedCredentialsOption\u003e(\n google::cloud::MakeServiceAccountCredentials(contents));\n return google::cloud::dataplex_v1::CatalogServiceClient(\n google::cloud::dataplex_v1::MakeCatalogServiceConnection(options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`dataplex_v1::CatalogServiceClient`](/cpp/docs/reference/dataplex/2.29.0/dataplex_v1_1_1CatalogServiceClient-service-account-snippet)\n- [`dataplex_v1::ContentServiceClient`](/cpp/docs/reference/dataplex/2.29.0/dataplex_v1_1_1ContentServiceClient-service-account-snippet)\n- [`dataplex_v1::DataScanServiceClient`](/cpp/docs/reference/dataplex/2.29.0/dataplex_v1_1_1DataScanServiceClient-service-account-snippet)\n- [`dataplex_v1::DataTaxonomyServiceClient`](/cpp/docs/reference/dataplex/2.29.0/dataplex_v1_1_1DataTaxonomyServiceClient-service-account-snippet)\n- [`dataplex_v1::DataplexServiceClient`](/cpp/docs/reference/dataplex/2.29.0/dataplex_v1_1_1DataplexServiceClient-service-account-snippet)\n- [`dataplex_v1::MetadataServiceClient`](/cpp/docs/reference/dataplex/2.29.0/dataplex_v1_1_1MetadataServiceClient-service-account-snippet)\n\nKeep in mind that we chose this as an example because it is relatively easy to understand. Consult the [Best practices for managing service account keys](https://cloud.google.com/iam/docs/best-practices-for-managing-service-account-keys) guide for more details.\n\n###### See Also\n\n[Authentication Components](https://cloud.google.com/cpp/docs/reference/common/latest/group__guac.html) - for more information on the factory functions to create [`google::cloud::Credentials`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1Credentials.html) objects."]]