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 is 2.37.0-rc, and this page details version information for network management, starting with that version and descending to version 2.11.0."],["The client libraries default to using Application Default Credentials for Google Cloud Services authentication, but this can be overridden."],["You can override the default authentication by utilizing the UnifiedCredentialsOption, like loading a service account key file as demonstrated in the example code provided."],["The provided example shows how to override authentication by explicitly loading a service account key file, which can be set as an option and can be used with the `MakeReachabilityServiceConnection` method."],["Refer to the \"Best practices for managing service account keys\" guide for more detailed information on managing keys, as well as \"Authentication Components\" for more information on creating `Credentials` objects."]]],[]]
