Unless otherwise configured, the client libraries useApplication Default Credentialsto 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 theUnifiedCredentialsOptionThe 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::cloudbuild_v1::CloudBuildClient(
google::cloud::cloudbuild_v1::MakeCloudBuildConnection(options));
}
Follow these links to find examples for other*Clientclasses:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThis page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, specifically focusing on the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version available is 2.37.0-rc, with documentation also available for multiple prior versions, ranging down to 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eUsers can explicitly load a service account key file to override the default credentials using \u003ccode\u003egoogle::cloud::MakeServiceAccountCredentials\u003c/code\u003e, providing greater control over authentication.\u003c/p\u003e\n"],["\u003cp\u003eExamples are provided for \u003ccode\u003ecloudbuild_v1::CloudBuildClient\u003c/code\u003e and \u003ccode\u003ecloudbuild_v2::RepositoryManagerClient\u003c/code\u003e, demonstrating the application of service account overrides in different client contexts.\u003c/p\u003e\n"],["\u003cp\u003eFor more details and alternative authentication methods, the document recommends consulting the "Best practices for managing service account keys" guide and the "Authentication Components" section.\u003c/p\u003e\n"]]],[],null,[]]
