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::tasks_v2::CloudTasksClient(
google::cloud::tasks_v2::MakeCloudTasksConnection(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 2025-04-17 UTC."],[[["The webpage provides documentation for overriding default authentication credentials in the context of Google Cloud C++ client libraries."],["The latest version available for the documentation is version 2.37.0-rc, with a full range of versions available down to 2.11.0."],["Users can override the default authentication using `UnifiedCredentialsOption`, as demonstrated in the provided C++ example."],["The best practices guide for managing service account keys should be consulted for a secure implementation, and there is also a link for more information on authentication components."]]],[]]
