If I arrive on china eastern on a domestic flight, how do I transfer to an international flight

Well, which terminal is your international flight in? Anyway, after arrival, you need to proceed with international flights transfer procedures at the D-I Transfer Counter , then check boarding pass and go through the Heath & Quarantine Inspection, pass through the Exit Frontier Inspection, as well as accept Security Inspection and Customs Inspection. Then wait for your flight.

I arrive on china eastern in terminal 2. I depart for the US on a Delta flight. I believe it is also in terminal 2.

As you will depart and leave at T2, here is the procedure for your transfer from Domestic or International:
1. Baggage Claim
2. Transfer Procedures
3.International Departure Procedures
Anything or location unclear, it is suggested to ask the staff there.

I have the same question. I didn't think that I would have to go to baggage since China Eastern would check it all the way through to my final stop in the US. Was hoping that I would get off one plane, walk to the new gate where my Delta flight is at.

Actually, it depends. The situation above is transit from Domestic to International. Is it the same as yours? Anyway, if you have had the baggage check-through on your airlines, there is no need to claim that by yourself.