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::migrationcenter_v1::MigrationCenterClient(
google::cloud::migrationcenter_v1::MakeMigrationCenterConnection(
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 2025-04-23 UTC."],[[["This page lists the available versions of the Migration Center C++ client library, ranging from version 2.13.0 to the latest release candidate 2.37.0-rc."],["By default, the client libraries utilize Application Default Credentials for Google Cloud Services authentication, but this can be overridden."],["To override the default authentication, you can supply a UnifiedCredentialsOption, such as loading a service account key file as demonstrated in the example."],["The provided example illustrates how to load a service account key file, which allows users to override default authentication credentials using the `UnifiedCredentialsOption`."],["More information on factory functions for creating `google::cloud::Credentials` objects can be found in the Authentication Components documentation."]]],[]]
