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."],[[["This webpage documents the available versions of the Essential Contacts C++ client library, ranging from version 2.12.0 up to the latest release candidate, 2.37.0-rc."],["The client libraries primarily use Application Default Credentials for authentication, but they provide flexibility to override this default behavior."],["You can override the default authentication by providing a UnifiedCredentialsOption, like loading a service account key file as shown in the provided code example."],["For further details on authentication, including creating `google::cloud::Credentials` objects, refer to the Authentication Components documentation."],["Consult the \"Best practices for managing service account keys\" guide for information on how to properly handle and secure your service account keys."]]],[]]
