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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 authentication.\u003c/p\u003e\n"],["\u003cp\u003eYou can override default credentials by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, which allows for explicit loading of a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe provided code example demonstrates loading a service account key file to create a \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e object.\u003c/p\u003e\n"],["\u003cp\u003eIt is advised to review the "Best practices for managing service account keys" guide for further security and best practices.\u003c/p\u003e\n"],["\u003cp\u003eAdditional information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects can be found in the "Authentication Components" documentation.\u003c/p\u003e\n"]]],[],null,[]]
