SSH is a wonderful tool. It has many advanced features which can make your life easier as a developer, but they are not always well known or understood. So today, let's introduce one of these: aliases.
When you are working on a project, you often have to switch between different servers: a local server, a test/staging server and a production server. So you find yourself typing this all day:
ssh user@virtual-machine ssh email@example.com ssh firstname.lastname@example.org
Some people find a workaround with shell aliases:
alias test="ssh email@example.com"
That works alright in most cases, but what happens for example when you have to use
scp or a
rsync: you have to type the full command again...
# SSH to production server, quick and easy prod # Copy a file from test server. #FAIL scp firstname.lastname@example.org:/path .
Thankfully, SSH offers aliases too. They are defined in
Host foo User user Hostname example.com
With that configuration in place, you can now do all of the following:
# ssh email@example.com ssh foo # scp firstname.lastname@example.org:/some/path /bar scp foo:/some/path /bar # rsync email@example.com:/some/path /bar rsync foo:/some/path /bar
I follow a convention for all my servers and use suffixes to identify which server I'm connecting too. So let's say I want quick access to all the environments of my project example. Here is what my config would look like:
Host example.dev User deploy Hostname virtual-machine Host example.test User deploy Hostname test.example.com Host example.prod User deploy Hostname www.example.com
This way, I can quickly go to any of those servers, and I don't have to remember their exact name, IP address, login, etc.:
ssh example.dev # local vm ssh example.test # testing server ssh example.prod # production server
Of course, the following now works too:
rsync -avz example.test:/var/www path
You don't have to limit yourself to
Hostname, you can use the full range of SSH options. Here is a more advanced configuration:
Host example Port 678 User special Hostname 22.214.171.124 LocalForward 8000 127.0.0.1:80 PreferredAuthentications publickey IdentityFile ~/.ssh/id_example_dsa Compression yes
You can find more information about the options available and the general format of the file in the man:
SSH aliases can dramatically ease your life. Use them!
Until next time, Cheers!