Ukraine wants EU integration and NATO membership, and there is nothing wrong with that. However in order to achieve it, I believe Ukraine should be prepared to permanently release its control over the Donbass region. It cannot defeat Russian-backed separatists in military conflict because Russia is simply too strong. But the Ukraine government should also avoid Putin's plan of the Donbass remaining an autonomous region within Ukraine, because he would use his influence over this region to politically interfere with the country's ambitions to join NATO, and thus preventing its future territorial security.
It would be much better if Ukraine insists that the Donbass region should become a weak little country of its own, which Russia may or may not annex in future to its own economic cost, especially as it will continue to incur further sanctions from the West.
Ukraine nationalists may balk at this kind of action, or see it as a defeat, but I think the prospect of free sovereignty, European economic integration, and the security of NATO membership is something that is ultimately worth paying a high price for, and could actually be seen as a victory against Putin's dictatorship in a moral sense. After all, Ukraine would still remain a fairly large country and its number of remaining Russian speakers - which Putin claims to be 'protecting' - would be considerably less.
Let's not forget that Putin's number one political goal is not really to re-construct the Soviet Union - but more simply to hold on to the Russian presidency for life and to have influence over others. He's much more of a self-centered right-wing fascist dictator, than a left-wing empire-building communist. Continued isolation and a severely weakened Russian economy would probably eventually lead to his political demise.
For some reason 
