Do I need SSL on discourse?

the green lock image on the address bar looks good and give awesome feeling to visitors
but I wanna know if SSL really required for discourse forum.

what I know about ssl is that normally required for ecommerce site?

It is not required technically. You can run the Discourse forum without SSL, but hey… it is simple and costs nothing to switch your forum to use free Lets’ Encrypt certificate Setting up HTTPS support with Let's Encrypt


ohhhhhhhhhhhhhhh it looks so many procedures to install ssl.
is it easy to follow tho?

If you have a standard, simple server configuration, with just Discourse running on the server then all it takes is couple of lines in the app.yml file.

There is one simple procedure in the link I have given, points 1-4 are all you need in ‘regular’ install (without CDN), few minutes of work.

Note that Google Chrome will start marking all HTTP sites insecure by default in July 2018.