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::parametermanager_v1::ParameterManagerClient(
google::cloud::parametermanager_v1::MakeParameterManagerConnection(
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 2025-04-09 UTC."],[[["This page provides instructions on how to override the default authentication credentials used by client libraries to interact with Google Cloud Services."],["By default, client libraries use Application Default Credentials, but users can override this by supplying the `UnifiedCredentialsOption`."],["The example code demonstrates how to load authentication credentials from a service account key file."],["The `Authentication Components` section has additional information about the factory functions to create `google::cloud::Credentials` objects."],["It is advised to check the \"Best practices for managing service account keys\" guide for in-depth information on credential management."]]],[]]
