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 2025-03-14 UTC."],[[["This page provides a list of available versions for the Migration Center service, ranging from version 2.13.0 up to the release candidate 2.37.0-rc, with version 2.27.0 as the current default."],["The default authentication method for client libraries is Application Default Credentials, which can be overridden when necessary."],["Overriding default authentication can be achieved by utilizing the `UnifiedCredentialsOption`, as demonstrated by loading a service account key file."],["Users should refer to the \"Best practices for managing service account keys\" guide for detailed information on managing service account credentials."],["More information on creating `google::cloud::Credentials` objects can be found in the Authentication Components documentation."]]],[]]