Display Popup from postgis db over WMS layer file using leaflets

[Ahsan Abbas]

i want to display popup information over WMS service file that i published from geoserver and using it in Leaflets. Below is the picture for illustration. 

Now i just want when user click any polygon the information related to it will be display as popup from postgis database, what are the possible ways to fetch information from db and display over each polygon ? right now i don't know how to do that, i am new to WebGIS, if someone share some good example it will be great for me.

Thanks...