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::essentialcontacts_v1::EssentialContactsServiceClient(
google::cloud::essentialcontacts_v1::
MakeEssentialContactsServiceConnection(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."],[[["The webpage provides documentation for various versions of the C++ client library, ranging from version 2.12.0 up to the release candidate 2.37.0-rc, with 2.37.0-rc being the latest."],["The content demonstrates how to override the default authentication credentials, typically Application Default Credentials, used by the client libraries."],["Users can override the default credentials by utilizing the `UnifiedCredentialsOption`, such as loading a service account key file, as shown in the provided example code."],["The example uses the `MakeServiceAccountCredentials` function to load the service key file, however, users are advised to follow the best practices for managing service account keys for a production environment."],["The page references additional documentation on the Authentication components for more details on the creation of `google::cloud::Credentials` objects."]]],[]]
