Building an 'image' for install on many devices

[offsprey]

I have used openwrt to build a stand-alone wifi file server / file hub from a Rav Power travel router. I would like a method to capture an 'image' of the router so it can be quickly duplicated on dozens of routers.

I work as a IT specialist for a government emergency response team. We work on wildfires, hurricanes, floods, and other incidents where there is often little to no internet. We have used openwrt to customize a couple of travel routers as file servers to distribute digital information like maps, shift assignments, and operational briefings to the units in the field. I have been tasked to duplicate this functionality on 25+ routers. It would be time consuming and somewhat error prone to manually provision each device, especially since the current supported build is a snapshot, and not well configured for travel router.

I apologize if this is a newb question that has been covered in depth elsewhere.

[Degenerate]

This is exactly what the image builder is for:

https://openwrt.org/docs/guide-user/additional-software/imagebuilder

You just need to make note of any extra packages you installed, and you can build them into the image with the PACKAGES= option. You can also make a backup of the settings on your prototype and incorporate that into the image using the FILES= option.