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::batch_v1::BatchServiceClient(
google::cloud::batch_v1::MakeBatchServiceConnection(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 2025-03-05 UTC."],[[["This webpage provides documentation for various versions of the C++ Batch API, ranging from version 2.11.0 up to the release candidate 2.37.0-rc."],["The primary focus of the content is how to override the default authentication credentials used by the C++ client libraries when interacting with Google Cloud services."],["Overriding the default authentication is accomplished using `UnifiedCredentialsOption`, which allows for specifying a service account key file."],["The example code demonstrates loading a service account key file and creating a `BatchServiceClient` with custom credentials."],["For advanced authentication methods and security best practices, users are directed to the \"Best practices for managing service account keys\" and the \"Authentication Components\" documentation."]]],[]]
