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."],[[["The latest available version is 2.37.0-rc, with numerous other versions, including the current version 2.21.0, also available for reference."],["The default authentication for client libraries uses Application Default Credentials, but this can be overridden when necessary."],["You can override the default credentials using `UnifiedCredentialsOption`, such as explicitly loading a service account key file, as demonstrated in the provided code example."],["For detailed information on creating `google::cloud::Credentials` objects, you can refer to the Authentication Components documentation."],["Service account key management is vital, and you can consult the best practices guide for service account keys for more information on this."]]],[]]
