Unless otherwise configured, the client libraries useApplication Default Credentialsto 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 theUnifiedCredentialsOptionThe 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::ContentServiceClient(
google::cloud::dataplex_v1::MakeContentServiceConnection(options));
}
Follow these links to find examples for other*Clientclasses:
[[["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 2025-09-04 UTC."],[[["\u003cp\u003eThe page provides documentation for overriding default authentication credentials in the Google Cloud C++ client libraries for Dataplex services.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version documented is 2.37.0-rc, and the content also lists available documentation for versions ranging from 2.11.0 up to 2.36.0, all of which pertain to overriding authentication for Dataplex services.\u003c/p\u003e\n"],["\u003cp\u003eIt details how to override default credentials using \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, with a specific example of loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eExamples of how to override credentials are provided for \u003ccode\u003eContentServiceClient\u003c/code\u003e, \u003ccode\u003eDataplexServiceClient\u003c/code\u003e, and \u003ccode\u003eMetadataServiceClient\u003c/code\u003e classes.\u003c/p\u003e\n"],["\u003cp\u003eIt references best practices for service account key management and offers a link to further information on authentication components within the C++ client library.\u003c/p\u003e\n"]]],[],null,["Version 2.11.0keyboard_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::ContentServiceClient(\n google::cloud::dataplex_v1::MakeContentServiceConnection(options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`dataplex_v1::ContentServiceClient`](/cpp/docs/reference/dataplex/2.11.0/dataplex_v1_1_1ContentServiceClient-service-account-snippet)\n- [`dataplex_v1::DataplexServiceClient`](/cpp/docs/reference/dataplex/2.11.0/dataplex_v1_1_1DataplexServiceClient-service-account-snippet)\n- [`dataplex_v1::MetadataServiceClient`](/cpp/docs/reference/dataplex/2.11.0/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."]]