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 2025-03-05 UTC."],[[["This document details how to override the default authentication credentials used by client libraries when interacting with Google Cloud Services."],["The client libraries primarily use Application Default Credentials for authentication, but this can be overridden when needed."],["Overriding default credentials can be achieved by using the `UnifiedCredentialsOption`, as demonstrated with an example using a service account key file."],["There are various available versioned pages of this document, all the way down to version 2.25.1, with the latest release candidate at 2.37.0-rc."]]],[]]
