migrate-database | A CLI for database migrations in Node.js | Runtime Evironment library

You should use flyway user parameter to do so: just add -Dflyway.user=racer to your maven command, that should work correctly! If you're using a flyway.properties file, just append flyway.user=racer to it.

Additionally users with postgres are supposed to be set as follows if using the url :

jdbc:postgresql://{$user}:{$optional_password}@{$host}:{$port}/{$db_name}{$GET_parameters}