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 documents different versions of the Google Cloud C++ client library, specifically for overriding authentication credentials, spanning from version 2.11.0 up to the latest release candidate 2.37.0-rc."],["The latest stable version documented is 2.36.0, while 2.37.0-rc is the most recent release candidate available for overriding authentication."],["The default method for client libraries to authenticate is via Application Default Credentials, but the UnifiedCredentialsOption can be used to override this."],["Overriding authentication can be done by loading a service account key file, which is demonstrated by the provided C++ code example."],["For best practices regarding managing service account keys and more information on creating Credentials objects, refer to the provided links to Google Cloud documentation."]]],[]]