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::networksecurity_v1::NetworkSecurityClient(
google::cloud::networksecurity_v1::MakeNetworkSecurityConnection(
options));
}
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 document provides a reference for Network Security authentication overrides, with version details ranging from 2.13.0 to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe default method for authentication with Google Cloud Services is through Application Default Credentials, but it can be overridden if needed.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default authentication by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, such as by loading a service account key file, with an example being shown in the content.\u003c/p\u003e\n"],["\u003cp\u003eThe provided example uses a service account key file to create authentication, but users are encouraged to refer to the "Best practices for managing service account keys" guide for more secure implementation.\u003c/p\u003e\n"],["\u003cp\u003eMore information about the \u003ccode\u003eCredentials\u003c/code\u003e objects and how to create them can be found in the "Authentication Components" section.\u003c/p\u003e\n"]]],[],null,[]]
