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 2025-03-14 UTC."],[[["This page provides documentation for overriding default authentication credentials when using Google Cloud client libraries, with version-specific information available from 2.11.0 up to the latest release candidate 2.37.0-rc."],["Client libraries typically use Application Default Credentials for Google Cloud service authentication, but this can be overridden when needed."],["You can override authentication by using the UnifiedCredentialsOption, which allows for explicitly loading a service account key file."],["The example code demonstrates how to load a service account key file using `google::cloud::UnifiedCredentialsOption` and `google::cloud::MakeServiceAccountCredentials`, with a note to consult best practices for service account key management."],["There are also external resources to find more information, such as the application default credentials, the unified credentials options, best practices for managing service account keys, and other authentication components."]]],[]]
