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::publicca_v1::PublicCertificateAuthorityServiceClient(
google::cloud::publicca_v1::
MakePublicCertificateAuthorityServiceConnection(options));
}
[[["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 2025-03-21 UTC."],[[["This document provides information on how to override the default authentication credentials used by client libraries when interacting with Google Cloud Services."],["The default authentication method is the Application Default Credentials, but this can be overridden using the UnifiedCredentialsOption."],["An example is provided demonstrating how to explicitly load a service account key file to override the authentication."],["The document references the Best practices guide for managing service account keys for more detailed information on the subject."],["It provides a list of documentation links for versions 2.25.1 to 2.37.0, offering the ability to reference information specific to each of those releases."]]],[]]
