Getting a handle on testing requires you become comfortable writing test. The place to start is with the simplest test you can think of. Even though Make will notify you if a file is missing, learning how to write these simple test and to format useful output is a valuable skill to practice.

Helper variable for a timestamp:
​DTS = $(shell date +%Y-%m-%dT%H:%M:%S-%Z)

​The first rule of naming conventions is that there isn't, nor will there ever be, a single best way to define a host name. The best you can do it to pick a standard that seems to work for your particular situation and stick with it for as long as it is useful.

The ideal host name provides just enough information to help identify the device but not so much information that the name limits the flexibility to accommodate future requirements.