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::profiler_v2::ProfilerServiceClient(
google::cloud::profiler_v2::MakeProfilerServiceConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page provides documentation for overriding authentication credentials when using Google Cloud client libraries, with a focus on the profiler service.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate for the profiler service is version 2.37.0-rc, while version 2.14.0 is displayed on the page as the default version selected, and various other version are also available.\u003c/p\u003e\n"],["\u003cp\u003eUsers can override the default Application Default Credentials by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e to specify alternative authentication methods, such as loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation provides an example demonstrating how to load a service account key file to authenticate, but it also refers to the best practices guide for managing service account keys for more in depth details.\u003c/p\u003e\n"],["\u003cp\u003eAdditional information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects can be found in the Authentication Components section.\u003c/p\u003e\n"]]],[],null,[]]
