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."],[[["The webpage provides a list of available versions for the `vmmigration-override-authentication` documentation, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc."],["The default authentication method for client libraries is Application Default Credentials, but this can be overridden if necessary for specific use cases."],["Users can override the default credentials by providing the `UnifiedCredentialsOption`, demonstrated with an example using a service account key file."],["The provided documentation is for `vmmigration`, which users can access the API by using the `VmMigrationClient`."],["For additional information on creating `google::cloud::Credentials` objects, you may refer to the Authentication Components section."]]],[]]
