There were no indications that the Soviet regime had any inclination of starting a war with Germany, though ti would probably not have joined the Axis either.

The Soviets actually tried to join the Axis in October-November 1940. The sticking point was that the Germans wanted the Soviets to agree to a split in spheres of influence along the Dardanelles and Bosporus, while the Soviets wanted a share of the Balkans.

Throw in things like Basis Nord, the massive amount of war-critical natural resources the Soviets shipped the Nazis 1939-1941, the German shipments of weapon systems (cruisers, aircraft, naval guns) and technical drawings to the Soviets, German diplomatic support for the invasion of Finland . . . well. The Soviets and Germans were awfully cooperative until Barbarossa, even if one stops short of saying they were allied.