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::optimization_v1::FleetRoutingClient(
google::cloud::optimization_v1::MakeFleetRoutingConnection(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 2025-03-14 UTC."],[[["This page provides documentation for various versions of the C++ optimization library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc."],["The primary focus of this documentation is on how to override the default authentication credentials used by the client libraries when interacting with Google Cloud Services."],["Users can override default credentials by using the `UnifiedCredentialsOption` and explicitly loading a service account key file as demonstrated in the provided code example."],["The documentation highlights the importance of proper key management and directs readers to the \"Best practices for managing service account keys\" guide for more in-depth information."],["Additional details on creating `google::cloud::Credentials` objects can be found in the linked \"Authentication Components\" documentation."]]],[]]
