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 2025-03-14 UTC."],[[["The latest version available is 2.37.0-rc, with a series of previous versions listed, ranging down to version 2.20.0."],["Client libraries typically use Application Default Credentials for Google Cloud Services authentication, but this can be overridden."],["You can override the default authentication by using `UnifiedCredentialsOption`, as demonstrated by explicitly loading a service account key file."],["The provided code example details how to set the authentication credentials using a service account key file's content."],["For further details and alternative methods, you can refer to the \"Authentication Components\" section, which includes information on `google::cloud::Credentials` objects."]]],[]]
