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::config_v1::ConfigClient(
google::cloud::config_v1::MakeConfigConnection(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 2025-03-05 UTC."],[[["This page provides documentation for overriding default authentication credentials when interacting with Google Cloud Services."],["The latest release candidate version available is 2.37.0-rc, with versions ranging down to 2.16.0, each with its own documentation link for overriding authentication."],["The default authentication method utilizes Application Default Credentials, but users can override this with the `UnifiedCredentialsOption`."],["An example is given showing how to explicitly load a service account key file for authentication purposes, though users should consult best practice documentation for account key management."],["The page directs users to find further information on how to create credentials objects in the Authentication Components section."]]],[]]
