Locked out of EC2 ubuntu instance

Question

root access worked on my EC2 instance for a couple of weeks until I did

sudo aptitude update

sudo aptitude upgrade

and now sudo asks for a password (which I have never been given). I can't log in as root (says "Please login as the user "ubuntu" rather than the user "root".").

Does anyone know a way out of this mess ?

SOLVED: the solution is here in the accepted response: Amazon EC2 asking me to move AMI, how to go about doing it?

Yes I'm using the .pem key generated from the ec2 management console — abcde123483, Mar 31 '11 at 19:30
And you're connecting with the ubuntu user? e.g. ssh -i ubuntu@ ? — Steve Mayne, Mar 31 '11 at 19:32
Sounds like your sudoers file might have changed - do you have permission to see it? /etc/sudoers — Steve Mayne, Mar 31 '11 at 19:39
Can you see when it was last updated? ls -l /etc | grep sudoers — Steve Mayne, Mar 31 '11 at 19:48
So that looks like a possible cause of the problem. Unfortunately there's no way to boot into single user mode on AWS. I think you might have to restore from a snapshot. I'm going to re-snapshot my EC2 machines right now! — Steve Mayne, Mar 31 '11 at 20:03
Thanks for the help. Nothing substantial was lost but it still stings a little. — abcde123483, Mar 31 '11 at 20:12
Can you set your own password using passwd? Not sure why I didn't think of this before! — Steve Mayne, Apr 02 '11 at 14:52

score 0 · Accepted Answer · answered Apr 02 '11 at 14:58

Set your password by typing passwd when logged in as user ubuntu. Once you've done this, you should be able to sudo using the same password - assuming the ubuntu user is still present in the sudoers file.

It sounds as though your sudoers file no longer allows sudo to operate without specifying a password. Once you've got sudo access again, you can change the behaviour in the sudoers file:

/etc/sudoers

Uncomment the line which says:

%sudo ALL=NOPASSWD: ALL

Locked out of EC2 ubuntu instance

1 Answers1