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::baremetalsolution_v2::BareMetalSolutionClient(
google::cloud::baremetalsolution_v2::MakeBareMetalSolutionConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThe latest version available is 2.37.0-rc, with numerous other versions, including 2.36.0, 2.35.0, and so on, listed down to version 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eClient libraries typically use Application Default Credentials for Google Cloud service authentication, but this can be overridden.\u003c/p\u003e\n"],["\u003cp\u003eAuthentication can be overridden by utilizing the UnifiedCredentialsOption, as demonstrated in the provided example of loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eRefer to the "Best practices for managing service account keys" guide for enhanced security and details.\u003c/p\u003e\n"],["\u003cp\u003eFor more details on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, consult the Authentication Components section.\u003c/p\u003e\n"]]],[],null,[]]
