Initialize connection arguments for postgres commands.

def initialize_db_args(self, settings, db_key):
        """ Initialize connection arguments for postgres commands. """
        self.print_message("Initializing database settings for %s" % db_key, verbosity_needed=2)

        db_member = self.databases[db_key]

        db_name = settings.get('NAME')
        if db_name and not db_member['name']:
            db_member['name'] = db_name

        db_member['password'] = settings.get('PASSWORD')

        args = []
        for key in ['USER', 'HOST', 'PORT']:
            value = settings.get(key)
            if value:
                self.print_message("Adding parameter %s" % key.lower, verbosity_needed=2)
                args.append('--%s=%s' % (key.lower(), value))

        db_member['args'] = args