Really good option - FAB Defense Scorpus Covert Polymer IWB Appendix Holster

Let's be honest here, it's very difficult to actually conceal a Glock 17, this does do a pretty close job of it though. It's not terribly comfortable, but this isn't because of the design, mostly the necessary size of. Basically impossible to wear in a seated position. This holster has some really nice features though overall, retains well, draws well, fits suppressor sights, and accommodates polymer 80 frames, at least the gen 3 Glock style ones