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 2025-04-02 UTC."],[[["The latest version available is 2.37.0-rc, with numerous other versions from 2.36.0 down to 2.11.0 also documented."],["This documentation provides instructions on how to override the default authentication credentials used by client libraries with Google Cloud Services."],["You can override the default by using the `UnifiedCredentialsOption`, such as explicitly loading a service account key file."],["The example shows how to load a service account key file using `MakeServiceAccountCredentials`, and it's important to consult best practices for managing service account keys."],["The documentation includes a link to \"Authentication Components\" for further information on creating `google::cloud::Credentials` objects."]]],[]]
