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 up to the latest release candidate 2.37.0-rc."],["The default authentication method for the client libraries is Application Default Credentials, but users can override this by providing a `UnifiedCredentialsOption`."],["An example of overriding authentication credentials demonstrates loading a service account key file using `UnifiedCredentialsOption` and `MakeServiceAccountCredentials`."],["For detailed information on creating `google::cloud::Credentials` objects, refer to the Authentication Components documentation."],["Users are advised to consult the best practices guide for managing service account keys for enhanced security and management strategies."]]],[]]