It doesnt get the server roles but i use this

SELECT'CREATE LOGIN [' + name + '] WITH PASSWORD = ' +

sys.fn_varbintohexstr(password_hash) +

' HASHED, SID = ' + sys.fn_varbintohexstr(sid) +

', DEFAULT_DATABASE = ' + QUOTENAME(default_database_name) +

', DEFAULT_LANGUAGE = ' + default_language_name +

', CHECK_EXPIRATION = ' +

CASE

WHEN is_expiration_checked = 0 THEN 'OFF'

ELSE 'ON'

END +

', CHECK_POLICY = ' +

CASE

WHEN is_policy_checked = 0 THEN 'OFF'

ELSE 'ON'

END +

CASE is_disabled

WHEN 0 THEN ''

ELSE '; ALTER LOGIN [' + name + '][ DISABLE;'

END

FROM master.sys.sql_logins

WHERE name not like '##%' and name <> 'sa'