Answer "yes" to ssh-copy-id first time run by script?

Question

The first time ssh-copy-id it will ask

# ssh-copy-id -i .ssh/id_dsa.pub [email protected]
The authenticity of host 'example.com (xxx.xxx.xxx.xxx)' can't be established.
RSA key fingerprint is 39:fb:5e:70:30:33:2b:18:17:e9:4f:2f:91:b5:d2:21.
Are you sure you want to continue connecting (yes/no)? 

Is it possible to script this, so the script just will answer yes?

Solution 1

If your ssh-copy-id doesn't support the StrictHostKeyChecking option, you can write a script that does:

1. Run ssh-keyscan against the target server to get the public key
2. Append that to the known_hosts file
3. Run ssh-copy-id

Solution 2

SSH has an option to automatically add any host keys to the trusted hosts file:

ssh-copy-id -i .ssh/id_dsa.pub -o StrictHostKeyChecking=no [email protected]

As an alternative, you could do the following:

echo "yes \n" | ssh-copy-id -i .ssh/id_dsa.pub [email protected]

Edit: since it appears these solutions don't work with ssh-copy-id, you could always create a ~/.ssh/config file with the following option in it:

StrictHostKeyChecking no

This should work with all SSH connections, regardless if they are invoked through a script or not.

Comments

[Sandra]

Sadly doesn't work, and ssh-copy-id doesn't have -o

[brain99]

Weird, it does report that switch when issuing ssh-copy-id -?

[ewwhite]

@sandra ssh-copy-id is a script. You can modify it to add -o StrictHostKeyChecking=no or disable that parameter in the ssh_config file.

[ewwhite]

Also, you don't need to specify the key location... ssh-copy-id servername works fine.

[Greg Petersen]

sudo sed -i.bak 's/ssh \$/ssh -o StrictHostKeyChecking=no \$/' $(which ssh-copy-id).

[ImranRazaKhan]

there is no -y option