800 Scrambler WHAT'S THIS? mystery part & oil

Hi All,
Was trying to change the front drive sprocket but could not get it off with chain attached, so undid a black screw on a black plastic assembly (which had a plinger shaft behind) and pulled it out to get more clearance.
Problem: Green oil stated running out the hole, (not engine oil I don’t think). I quickly refitted the plunger, but now am worried what the oil is from, or for or whatever.
Could this be a Ducati chain oiler concept?
Any clues greatly accepted and photo attached.