public String[] getDockerAdditionalArgs() {
        return new String[] {"-p", "5432:5432",
            "-e", "POSTGRES_PASSWORD=" + getRootPassword(),
            "-e", "POSTGRES_USER=" + getRootUser(),
            "-e", "POSTGRES_DB=" + dbName,
            "-d"
        };
    }
MySQLExternalDB is a extension of abstractExternalDB
Designed for MySQL external database connection
itests/util/src/main/java/org/apache/hadoop/hive/ql/externalDB/PostgresExternalDB.java