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::parallelstore_v1::ParallelstoreClient(
google::cloud::parallelstore_v1::MakeParallelstoreConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 document details how to override the default Application Default Credentials used by client libraries for Google Cloud Services.\u003c/p\u003e\n"],["\u003cp\u003eOverriding the default authentication can be achieved by providing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, as demonstrated with an example loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe example provided is intended to be easy to understand and users are advised to consult the guide on best practices for managing service account keys for further details.\u003c/p\u003e\n"],["\u003cp\u003eThe document provides a list of different versions, with the latest version being 2.37.0-rc, and going back until 2.31.0.\u003c/p\u003e\n"],["\u003cp\u003eAdditional information on the factory functions to create \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects can be found in the provided Authentication Components link.\u003c/p\u003e\n"]]],[],null,[]]
