This is basically an E Blues tune.
Therefore you can use the E minor pentatonic scale.
The only deviation is the G chord.
This is not really a problem since the G note is in the E minor pentatonic scale.
Therefore, you can simply use the Em Pentatonic scale.
It is not the only thing you can use, but everything you need to solo is in the Em pentatonic
If you are having trouble soloing over this tune, just use the Em pentatonic, and learn to hit the right notes thru the chord progression.
(Hint: hit the G note on the G chord)
After 10,000 repetitions you will have it down.