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::datamigration_v1::DataMigrationServiceClient(
google::cloud::datamigration_v1::MakeDataMigrationServiceConnection(
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 overriding authentication credentials when using the client libraries to interact with Google Cloud Services, with a focus on Data Migration."],["The default authentication method utilizes Application Default Credentials, but users can override this by employing the `UnifiedCredentialsOption`."],["The provided code example demonstrates how to load a service account key file explicitly to override the default credentials."],["The page also contains a list of previous versions of the Data Migration document, starting from 2.11.0 all the way to 2.37.0-rc."],["The Authentication Components documentation is suggested as a resource for further information regarding the creation of `google::cloud::Credentials` objects."]]],[]]
