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 2025-03-05 UTC."],[[["This document provides a list of versioned documentation for C++ optimization reference, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["The primary focus of this page is on how to override the default authentication credentials used by client libraries when interacting with Google Cloud Services."],["Users can override the default authentication using `UnifiedCredentialsOption`, demonstrated via an example of loading a service account key file."],["The example code utilizes `google::cloud::UnifiedCredentialsOption` and `google::cloud::MakeServiceAccountCredentials` to explicitly set authentication credentials, offering an alternative to Application Default Credentials."],["The document also points readers towards the \"Authentication Components\" section for creating `google::cloud::Credentials` and the \"Best practices for managing service account keys\" guide for further authentication details."]]],[]]
