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::networkmanagement_v1::ReachabilityServiceClient(
google::cloud::networkmanagement_v1::MakeReachabilityServiceConnection(
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 release candidate version for this documentation is 2.37.0-rc, with the full list of versions ranging from this all the way back to 2.11.0."],["The documentation primarily focuses on how to override the default authentication credentials used by client libraries when interacting with Google Cloud Services."],["By utilizing the `UnifiedCredentialsOption`, you can explicitly specify and load a service account key file for authentication, allowing you to bypass Application Default Credentials."],["The provided example showcases how to load a service account key file and create a `ReachabilityServiceClient` with the specified credentials, which is highlighted as a simplified example for understanding."],["For further details on managing service account keys and authentication components, you can consult the linked \"Best practices for managing service account keys\" guide and the \"Authentication Components\" section."]]],[]]
