MacOSX - how to automatically load ssh-key into RAM?

Question

SSH

Good day!
The situation is this - there is Mac OS X 10.10. An ssh-key has been created in the system to work with GitHub.
The problem is that every time I start my iMac again ( let's skip the topic of using sleep or hypernation for now ), I have to perform the following procedure:
$ ssh-add ~/.ssh/github_key
How can I automate this process? So that the system automatically loads the ssh key every time it starts?
PS
Even on Linux, when I try to connect to GitHub, my ssh key is automatically loaded and the system only asks for a password in the popup window. And here - all only handles. (

Answer 1

Strangely, the issue resolved itself. It was enough to create a new ssh-key for use on GitHub and leave it alone on the service ( up to this point I had two keys ).
Now my iMac Yosemite ( absolutely clean after reinstallation - no settings in this regard ) does not ask me anything - the key is loaded automatically. In this way, I can soon forget about the existence of this ssh-key at all )

Answer 2

in ~/.ssh/config we write

Host github.com
    HostName github.com
    IdentityFile ~/.ssh/github_key
    User ваш_для_гитхаба
    Port 22