Connecting to an Ubuntu instance fails

[snay2]

Describe the bug
When using simple-ec2 connect to log in to an EC2 instance using an AMI that is not a flavor of Amazon Linux, user encounters an SSH error "Permission denied (publickey)". This is because our EC2 Instance Connect helper code hardcodes the username of ec2-user, which is not correct for Ubuntu. The username in that case should be ubuntu. Red Hat and SUSE instances also fail to connect, but I'm not sure if they are because of the username or something else.

Steps to reproduce

1. Launch an instance with any configuration and an Ubuntu AMI, using simple-ec2 launch
2. Attempt to connect to that instance with simple-ec2 connect

Expected outcome
simple-ec2 connect should open an SSH connection and present the user with a shell to the instance. These steps work correctly for instances based on an Amazon Linux AMI.

Application Logs

Connecting to instance failed: exit status 255Warning: Permanently added 'ec2-3-143-5-51.us-east-2.compute.amazonaws.com' (ED25519) to the list of known hosts.
ec2-user@ec2-3-143-5-51.us-east-2.compute.amazonaws.com: Permission denied (publickey).

Environment

• App Version: 0.8.2
• OS/Arch: macOS 12.4

[fddayan]

please fix this ! +1