How to work with file system isolation in Docker?

Question

System administration

I started getting acquainted with Docker, but I still don’t understand its principle of working with the file system.
Let's say I deployed nginx in Docker, so I need to throw /etc/nginx/ + /var/www/ + /etc/ssl/ (there are ssl keys for the site/sites).
And how to throw them correctly? Or is it completely different? Help to understand, please.

Answer 1

In order to mount a /home/User/WebApps/Site1/apphost machine directory to a directory /var/www/htmlin a container, add the following to the container run command:

[...] -v /home/User/WebApps/Site1/app:/var/www/html [...]

Answer 2

Docker hole. There is no isolation there.