Why can't I ssh-copy-id to an EC2 instance?

Question

I have a ubuntu Natty instance on EC2, and I can SSH into it by

ssh -v -i ec2-keypair ubuntu@ubuntu@XXXX.compute-1.amazonaws.com

But I'd like to set up password less sshing. So I tried these options and nothing is working:

 $ ssh-copy-id -i ~/.ssh/id_rsa.pub ubuntu@XXXX.compute-1.amazonaws.com
Permission denied (publickey).

 $ ssh-copy-id -i ~/.ssh/ec2-keypair ubuntu@XXXX.compute-1.amazonaws.com
/usr/bin/ssh-copy-id: ERROR: No identities found

 $ ssh-copy-id -i ~/.ssh/id_rsa.pub root@XXXX.compute-1.amazonaws.com
Permission denied (publickey).

Answer 1

I needed to run

ssh-add ~/.ssh/ec2-keypair

Answer 2

I had the same problem: ssh-copy-id gives the error Permission denied (publickey) on an AWS EC2 instance. I was sure that I set all the permissions correctly using chmod.

In addition, I needed to change this line in /etc/ssh/sshd_config from

PasswordAuthentication no

to

PasswordAuthentication yes

I guess that's because ssh-copy-id asks for your password.

Then the error disappeared.