Friday, June 10, 2016

How to create an SSH shortcut

If you are constantly needing to SSH into multiple servers, it can real daunting to remember all the different usernames, hostnames, IP addresses, and even sometimes custom private keys to connect to them. It’s actually extremely easy to create command line shortcuts to solve this problem. There’s two major ways to do it, and we’ll discuss the pros and cons of each.
SSH on *NIX machines, such as Linux or Mac, have default shortcut functionality right out of the box. It’s very straight forward to setup, too. For those two reasons, this is my preferred way of setting up SSH shortcuts. The first step is to navigate to your .ssh folder:

cd ~/.ssh

Following this, you’ll need to create a file calledconfig. Here’s how to do it with Vim:

vim config

From here, you can now create shortcuts. You can specify the hostname, username, port, and the private key. For a full list of options, please visit the official docs. Here’s an example of how to structure the file:

Host scotch
    HostName scotch.io
    User nick
<br>
Host example2
    HostName example.com
    User root
<br>
Host example3
    HostName 64.233.160.0
    User userxyz123
    Port 56000
<br>
Host amazon1
    HostName ec2.amazon.com
    User ec2-user
    IdentityFile /path/to/special/privatekey/amazon.pem

Now, you can simply SSH into any of these servers with these simple commands:

ssh scotch
ssh example2
ssh example3
ssh amazon1

If this isn't working for you, trying changing the permissions of the config file like this:

chmod 600 ~/.ssh/config

#Method 2: Create aliases for your shell

This method involves creating an alias for your shell (or terminal). You can use this for creating any type of shortcut you want, but a lot of people use them for SSH shortcuts. To set this up, you'll need to navigate to your.bash_aliases file (or some people do this in .bashrcor .bash_profile). The following command will create the .bash_aliases file if it doesn't exist or just edit it if it already does using Vim.

vim ~/.bash_aliases

Here you can add as many shortcuts as you want. Here's how to add the same SSH shortcuts from above:

alias scotch='ssh nick@scotch.io'
alias example2='ssh root@example.com'
alias example3='ssh userxyz123@64.233.160.0 -p 56000'
alias amazon1='ssh ec2-user@ec2.amazon.com -i /path/to/special/privatekey/amazon.pem'

After you add those and save the file, you'll need to "reboot" the aliases file with:

source ~/.bash_aliases

Once that is completed, you can now SSH into all of those same boxes by just typing the following:

scotch
example2
example3
amazon1

This method provides additional flexibility that the first method might not be able to provide, but it really comes down to a matter of preference for most use cases.

No comments: