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::networkservices_v1::NetworkServicesClient(
google::cloud::networkservices_v1::MakeNetworkServicesConnection(
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 2025-03-21 UTC."],[[["The latest version available is 2.37.0-rc, with numerous other versions, down to 2.12.0, also listed."],["Client libraries typically use Application Default Credentials (ADC) for authentication with Google Cloud Services."],["You can override the default authentication by using the `UnifiedCredentialsOption`, such as loading a service account key file."],["The provided example demonstrates how to load a service account key file, which can be used as an override, and this is done for its ease of understanding."],["For more details on how to create `google::cloud::Credentials` objects, refer to the Authentication Components section."]]],[]]
