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::osconfig_agentendpoint_v1::AgentEndpointServiceClient(
google::cloud::osconfig_agentendpoint_v1::
MakeAgentEndpointServiceConnection(options));
}
Follow these links to find examples for other *Client classes:
[[["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 C++ client libraries for OS Config."],["The latest release is version 2.37.0-rc, and the page contains links to versions ranging from 2.11.0 to 2.37.0-rc."],["The default authentication method utilizes Application Default Credentials, but the UnifiedCredentialsOption can be used to override this."],["An example demonstrates loading a service account key file to authenticate, and there are links for `AgentEndpointServiceClient`, `OsConfigServiceClient`, and `OsConfigZonalServiceClient` examples."],["Users are encouraged to consult the Best practices for managing service account keys guide and the Authentication Components page for more information."]]],[]]