My understanding is that the national strike day is December 5 - a day where when you're in France you bettre stay at home (unless you want to go and demonstrate in the street), and where you avoid France if you're not there.
However, for subsequent days, the preview is that trains and Paris public transport (RATP) may continue to strike as their strike is an "extendable" one. At the same time, I understand, that things go back to normal on December 6th. Which de fact would mean that ground services in CDG should be up and running, whilst the AF network may still be very disturbed as AF planes and crews are in the wrong places.
Thus, for flying from/to France:
- on December 5, don't. No airline, no airport
- on December 6, don't fly Air France. Other airlines are hopefully OK