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::shell_v1::CloudShellServiceClient(
google::cloud::shell_v1::MakeCloudShellServiceConnection(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 2025-03-21 UTC."],[[["This page provides documentation for overriding default authentication credentials when using Google Cloud client libraries in C++."],["The latest release candidate version is 2.37.0-rc, with a list of all other available versions provided, ranging back to version 2.11.0."],["By default, client libraries use Application Default Credentials for authentication, but you can override this behavior."],["You can override the default authentication by providing a `UnifiedCredentialsOption`, such as explicitly loading a service account key file."],["For best practices in managing service account keys, refer to the linked guide, and for further information about creating `google::cloud::Credentials` objects, see the Authentication Components section."]]],[]]
