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::apikeys_v2::ApiKeysClient(
google::cloud::apikeys_v2::MakeApiKeysConnection(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 2025-04-02 UTC."],[[["The webpage provides documentation for overriding default authentication credentials when using Google Cloud C++ client libraries."],["It details how to use `UnifiedCredentialsOption` to override the default Application Default Credentials (ADC) and load credentials from a service account key file."],["The documentation includes versioned reference links for API keys, ranging from the latest release candidate `2.37.0-rc` down to version `2.11.0`."],["It references external documentation for additional details on authentication components and best practices for managing service account keys."]]],[]]
