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 2025-03-21 UTC."],[[["The latest version available is 2.37.0-rc, with numerous other versions from 2.36.0 down to 2.11.0 also being accessible."],["The content explains how to override default authentication credentials, which typically rely on Application Default Credentials, using the `UnifiedCredentialsOption`."],["You can load a service account key file explicitly by creating a `google::cloud::Options` object and setting the `UnifiedCredentialsOption` with the service account key file contents using `MakeServiceAccountCredentials`."],["The example code demonstrates how to load a service account key file and use it for authentication, and it is suggested that you should reference the \"Best practices for managing service account keys\" guide for more details."],["The document \"Authentication Components\" is provided for additional information about creating `google::cloud::Credentials` objects."]]],[]]
