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::apikeys_v2::ApiKeysClient(
google::cloud::apikeys_v2::MakeApiKeysConnection(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 webpage provides documentation for overriding default authentication credentials when using Google Cloud C++ client libraries, specifically referencing `apikeys-override-authentication`."],["The latest available version for reference is `2.37.0-rc`, and the page lists versions all the way down to `2.11.0` with corresponding links."],["The default client libraries utilize Application Default Credentials for authenticating with Google Cloud Services, but there are options to override these defaults."],["Users can override the default credentials by using `UnifiedCredentialsOption`, and the example provided demonstrates loading a service account key file."],["The page also includes a link to the \"Authentication Components\" documentation for further details on `google::cloud::Credentials` objects, and another to the \"Best practices for managing service account keys\" guide."]]],[]]
