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::cloudquotas_v1::CloudQuotasClient(
google::cloud::cloudquotas_v1::MakeCloudQuotasConnection(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 links provided for other recent versions ranging from 2.36.0 down to 2.20.0."],["The client libraries typically authenticate using Application Default Credentials, but you can override this with the UnifiedCredentialsOption."],["To override the default authentication, you can provide a service account key file via the UnifiedCredentialsOption, as shown in the example code using MakeServiceAccountCredentials."],["For detailed information on creating Credentials objects, refer to the Authentication Components documentation."],["There is a recommended best practices guide for managing service accounts keys that users should consult."]]],[]]
