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::ids_v1::IDSClient(
google::cloud::ids_v1::MakeIDSConnection(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."],[[["This page lists various versions of the C++ library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc, providing links to documentation for each version's authentication override details."],["The default authentication method for client libraries is Application Default Credentials, but you can override it using `UnifiedCredentialsOption`."],["Overriding default authentication can be done by loading a service account key file, as demonstrated in the provided C++ example code using `MakeServiceAccountCredentials`."],["The guide recommends reviewing the best practices for managing service account keys, and the documentation on Authentication Components for more information on creating `google::cloud::Credentials` objects."]]],[]]
