I currently provide technical support for a very niche product sold by a relatively big-name company (at least within this particular industry).
However, they are planning on ending support in a few years, and there will be dozens of clients (each themselves a company) who still use this product because changing to something else will either be prohibitively expensive, or just not technically feasible.
My question is this: would it be legal for me to provide support, documentation, and software (all written 100% by me, with nothing copyrighted by my employer) to these former clients at a small fee, as long as I do it "off the clock" with my current employer (the same employer who originally provided support for the product)?
The customers are aware of the end of official support, so it would be clear to them that I am offering my services on the side, and not as a representative of my employer.
My chief concerns are whether this would get me fired if my employer found out, and whether I could face legal action. I signed a non-compete agreement when I was hired, but I don't know if this counts as competition if I'm providing a service which the company explicitly no longer provides.
I understand it might be difficult to give accurate advice without knowing more about the product/employer, but I'm not comfortable naming anything here. I appreciate any advice that can be offered in spite of that.
Update 1: For clarification, my current employer is the large company which created and previously supported the product. They are discontinuing support because the product is about a decade old, and no longer has enough clients with enough problems for the project to remain profitable.