Alestic.com - A Personal AWS Blog by Eric Hammond

configure your own ssh username in user-data

The official Ubuntu AMIs create a default user with the username ubuntu which is used for the initial ssh access, i.e.:

ssh ubuntu@<HOST>

You can create other users with your preferred usernames using standard Linux commands, but it is difficult to change the ubuntu username while you are logged in to that account since that is one of the checks made by usermod:

$ usermod -l myname ubuntu
usermod: user ubuntu is currently logged in

There are a couple ways to change the username of the default user on a new Ubuntu instance; both passing in special content for the user-data.

Approach 1: CloudInit cloud-config

Each AMI publisher on EC2 decides what user (or users) should have ssh access enabled by default and what ssh credentials should allow you to gain access as that user.

For the second part, most AMIs allow you to ssh in to the system with the ssh keypair you specified at launch time. This is so common, users often assume that it is built in to EC2 even though it must be enabled by each AMI provider.

Unfortunately, there is no standard ssh username that is used to access EC2 instances across operating systems, distros, and AMI providers.

Here are some of the ssh usernames that I am aware of at this time: