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++ Essential Contacts client library, ranging from version 2.12.0 to 2.37.0-rc, with 2.37.0-rc being the latest release candidate."],["The default authentication for the client libraries is through Application Default Credentials, but this can be overridden when needed, for instance when a specific service account key file must be used."],["Authentication credentials can be overridden by providing the `UnifiedCredentialsOption`, which is demonstrated with an example that details the process of loading credentials from a service account key file."],["The `Best practices for managing service account keys` guide provides detailed information for managing service account keys, which may be necessary depending on the specific use case."],["Additional information regarding the creation of `google::cloud::Credentials` objects can be found in the `Authentication Components` section."]]],[]]
