I'd say it this way, 'Такая жизнь, приятель. Так всегда.' You can also say, 'Это жизнь, приятель. Так всегда.'
The literal translation of the last part of the phrase - 'Это просто путь, которым она (жизнь) идёт.' But we don't say like this, therefore it's better to convey the main meaning. If it goes this way, it means that it always goes this way, and it is always like this. So, 'Так всегда' is OK for this situation.
I hope I didn't confuse you. But if anything is unclear, please ask :).