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::scheduler_v1::CloudSchedulerClient(
google::cloud::scheduler_v1::MakeCloudSchedulerConnection(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 2025-04-02 UTC."],[[["This page provides documentation for overriding default authentication credentials when using Google Cloud C++ client libraries with various versions available."],["The latest version documented is 2.37.0-rc, and historical versions are available back to 2.11.0."],["By default, client libraries authenticate with Google Cloud Services using Application Default Credentials, however the default can be overriden."],["You can override the default credentials by providing the `UnifiedCredentialsOption`, demonstrated by loading a service account key file."],["The page references additional documentation on \"Authentication Components\" and \"Best practices for managing service account keys\" for further information on credentials."]]],[]]