My ideal ssh client config set-up

Recently I was asked how I’d managed to set up alias’s for all of the development servers I use on a day to day basis on my work laptop (a MacBook Pro), and how I had managed to set a default username for all outgoing connections. To which I replied I’d just set up my most commonly used connections in my ssh config file. What follows is a sample of my ssh config, which will hopefully help you to write your own.

If you do want to set up your own ssh config then first things first, let’s make sure you have the correct directories set up with the correct permissions.

$ mkdir ~/.ssh/
$ touch ~/.ssh/config

Make sure that only your user can read your .ssh directory and the config file.

$ chmod -R 600 ~/.ssh

Now that you have your config file, you can put some values in it. The main things you’ll need to put in the file are:

• Host  – The alias(s) you wish to use
• User  – The usename you connect with
• HostName  – The fully qualified domain name of the server

E.g.

Host carlcasbolt blog
User ccasbolt
HostName 216.239.32.10 

Host dev
User ccasbolt
HostName dev.example.com 

Host *
User ccasbolt

The example above shows that the value for Host can contain more then one option. This is for people who want to have more then one alias for a connection. I find this useful at times as I sometimes forget what alias I’ve set up at work because we have so many machines. Once you’ve set up your config you can go from using this:

$ ssh dev.example.com -l ccasbolt

To using something far nicer like:

$ ssh dev

Using scp becomes a lot easier with these alias’s set up.

Without ssh config

$ scp filename ccasbolt@dev.example.com:./path/to/put/file

With ssh config

$ scp filename dev:./path/to/put/file

The wildcard ‘*’ also comes in handy when I’m using my work machine as it has a different username to my hosting. If I was to use just ssh dev.example.com then it would use the same username I use on my laptop. To fix this you can set the default username with Host * and it will use that rather the username on your local machine.

Host *
User ccasbolt