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::vmmigration_v1::VmMigrationClient(
google::cloud::vmmigration_v1::MakeVmMigrationConnection(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."],[[["This page provides documentation for various versions of the `vmmigration-override-authentication` feature, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["The client libraries typically use Application Default Credentials for Google Cloud Services authentication, but this behavior can be overridden."],["You can override the default authentication by providing the `UnifiedCredentialsOption`, as demonstrated by loading a service account key file."],["The example code provided shows how to load a service account key file using the `UnifiedCredentialsOption` and `MakeServiceAccountCredentials`."],["The `Authentication Components` section provides further information on the factory functions to create `google::cloud::Credentials` objects."]]],[]]
