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::policytroubleshooter_iam_v3::
PolicyTroubleshooterClient(
google::cloud::policytroubleshooter_iam_v3::
MakePolicyTroubleshooterConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 the Policy Troubleshooter service, with specific examples on how to override default authentication credentials in C++.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate for the Policy Troubleshooter is version 2.37.0-rc, while version 2.22.1 is specifically being highlighted with authentication examples.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default Application Default Credentials by using \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and loading a service account key file as shown in the C++ code example.\u003c/p\u003e\n"],["\u003cp\u003eThere are various versions of the Policy Troubleshooter documented here, spanning from version 2.11.0 to 2.37.0-rc, each with their own specific documentation.\u003c/p\u003e\n"],["\u003cp\u003eAdditional details and best practices for managing service account keys are available in the linked guide.\u003c/p\u003e\n"]]],[],null,[]]
