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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 document provides versioned documentation for the Policy Troubleshooter, covering versions from 2.11.0 up to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe content details how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services using the UnifiedCredentialsOption.\u003c/p\u003e\n"],["\u003cp\u003eThe example demonstrates loading a service account key file explicitly to override authentication credentials, with best practices linked for guidance.\u003c/p\u003e\n"],["\u003cp\u003eExamples for other \u003ccode\u003e*Client\u003c/code\u003e classes, such as \u003ccode\u003epolicytroubleshooter_iam_v3::PolicyTroubleshooterClient\u003c/code\u003e and \u003ccode\u003epolicytroubleshooter_v1::IamCheckerClient\u003c/code\u003e, are also provided.\u003c/p\u003e\n"],["\u003cp\u003eThe document includes links to the "Authentication Components" section, which offers further information on factory functions to create \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
