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."],[[["This page provides documentation for overriding default authentication credentials when interacting with Google Cloud Services using C++ client libraries."],["The latest version of the documentation is 2.37.0-rc, and there is an array of previous versions ranging from 2.36.0 down to 2.11.0 available."],["The client libraries typically rely on Application Default Credentials for authentication, but they can be overridden by providing the `UnifiedCredentialsOption`, as shown in the example with a service account key file."],["For in-depth information on managing service account keys, one can refer to the provided guide, and for further details on creating credentials objects, consult the \"Authentication Components\" documentation."]]],[]]
