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 the library being for Google Cloud Essential Contacts."],["The default authentication method for the client libraries is Application Default Credentials, but it is also possible to override this using the UnifiedCredentialsOption."],["To override the default authentication, you can use the provided example, which shows how to explicitly load a service account key file, though it's suggested to use it only as a basic example."],["The UnifiedCredentialsOption can be set within the Options object, allowing you to customize the authentication method for your Google Cloud service connections."],["For more detailed information on creating Credentials objects, you can refer to the Authentication Components documentation."]]],[]]
