We bought the LED lights from IKEA that they have for use in their PAX wardrobe units. They have the sensor that makes them go on/off when the door is open/closed. You can string them together and they plug into a regular outlet. They work great and were very inexpensive. We put them up and down the sides and the light angles back into the storage area, so the shelving doesn't block the light.

A motion detector aimed at the door?

They are usually sold as light switches, but I have seen add-ons for entry lights that screw into the sockets.

Good ideas - we haven't bought the lighting yet either so have flexibility on what to use - have access to basement do can run direct wire or have transformer accessible in basement under floor. Maybe something for undercab like lights? Recommendations? Experience with hafele loox? Others? Would prefer something not just plugged into outlet

If the pantry is classified as a closet you'll be limited as to the type of lighting you can install.

There are many styles of LED lighting that have a simple occupancy sensor that can be aimed at the door. You must have either low voltage, or a covered or recessed fixture if it's line voltage.

My contractor replaced the ceiling light with a canned light connected to a motion detector switch. The light comes on when the door is opened. Love it.

It will have fixed shelves on one recessed side and large pull out shelves directly behind door. So won't be able to walk in anymore - sized just right for those huge packages of paper towels etc. anyone have specific brands you'd recommend?

My builder put it a plunger type switch in the hinge side of the door. We open the door and the light comes on. Close the door and the light goes off.