Canada is not compatible with Russia, so forming a military alliance is a crazy idea.
Putin is the aggressor who has invaded an European country just because their actions did not suit him.
There are no acceptable excuses for the invasion, it's a very dangerous game he is playing as Russia cannot live with the sanctions in the long run.
At the very best he can hope to get away with an agreement that Ukraine will never join EU or NATO, and will stay neutral forever.
Even then, there is no 100% guarantee that Ukraine will not go back on that deal in the future.