HDHomerun is the commercial solution that is relatively painless assuming you have something that can run a client that supports it
Open source, you probably want to look at tvheadend and a USB DVB-T tuner (hauppauge still make decent ones I believe) attached as the next most straightforward option, it can take a little bit to get set up but it’s pretty seamless once it is. Same caveat about clients











Cortisol addicts, all of them