Here is the link to the thigh holster referred to above:
The pictures all show it with a snub nosed revolver, but as noted above it does come for a Glock 26 and the frame that goes into the holster is the same for a 17 and a 26. I have no guarantee that the 17 will fit (you should probably ask them) but I bet it does. I have a Galco ankle glove (an ankle holster) for the 26, and the 17 fits in it just fine. Odds are the body of the holster used for the thigh holster is the same as the ankle holster. In fact, you could probably use an ankle holster if you had really skinny legs.