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."],[[["The latest version of the documentation is 2.37.0-rc, with a range of versions available from 2.36.0 down to 2.25.1."],["Client libraries typically use Application Default Credentials for Google Cloud Services authentication, but this default can be overridden."],["Overriding the default authentication can be achieved by supplying the `UnifiedCredentialsOption`, as demonstrated with the example of loading a service account key file."],["The provided example uses a service account key file for overriding authentication, which is easy to understand but users should see the best practices for managing service account keys."],["Additional information on creating `google::cloud::Credentials` objects can be found in the Authentication Components documentation."]]],[]]
