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::privateca_v1::CertificateAuthorityServiceClient(
google::cloud::privateca_v1::MakeCertificateAuthorityServiceConnection(
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 2025-03-14 UTC."],[[["The latest version available is 2.37.0-rc, with numerous preceding versions down to 2.11.0 also accessible."],["The client libraries generally use Application Default Credentials for Google Cloud service authentication, but this can be overridden."],["Authentication can be overridden by using the `UnifiedCredentialsOption` to load specific credentials, such as those from a service account key file."],["The provided code demonstrates how to explicitly load credentials from a service account key file as an example of credential override."],["For best practices regarding service account keys and creating `google::cloud::Credentials` objects, consult the linked guides on managing service account keys and authentication components, respectively."]]],[]]