SSH asks password when invoke it in script

Question

I have one master and four slave computers. I generated rsa public/private key on master PC. Then I copied publickey (id_rsa.pub) to slave machines as authorized_keys.

It doesn't ask password when I invoke SSH like this on master PC's terminal:

ssh –o UserKnownHostsFile=/dev/null –o StrictHostKeyChecking=no hduser@slave1

I wrote this script to automatically login slave machines without asking password.

SERVER_LIST=`cat /home/hduser/slaves` # slave1, slave2 ...
USERNAME=hduser
for host in $SERVER_LIST; do 
ssh –t –o UserKnownHostsFile=/dev/null –o StrictHostKeyChecking=no -l ${USERNAME} ${host}; 
done

SSH is asking slaves passwords when I use this script. I'm getting this message when use SSH with -vv option:

-vv option

I changed permissions on master PC and slave PC.

sudo chmod 700 -R ~/.ssh
sudo chown hduser ~/.ssh

It still asking password. What am I missing? How can I fix it?

It can ask me slave1's password without `hduser@`. I thought same thing and added it to script but nothing change. — Eyüp Alemdar, Mar 21 '14 at 16:08
Try to use add `-v` or `-vv` flag to ssh in the two cases, and compare the output --- maybe you can spot the problem that way. — Rmano, Mar 21 '14 at 16:12
see if any of [these answers](http://askubuntu.com/q/110814/184942) help. — Registered User, Mar 21 '14 at 16:14
I mean, try `ssh -v -o ...` from terminal (when it works), save the verbose output. Do the same for the `ssh ` in the script. Save it too. Normally this is sufficient to help you spot the problem, otherwise put the output in the question. — Rmano, Mar 21 '14 at 16:15
And also check that you have set the correct permissions, probably you need to have the same permissions for the key file and your script. — Registered User, Mar 21 '14 at 16:16
One more thing, use `@` to reply to users, otherwise we won't be notified. — Registered User, Mar 21 '14 at 16:18
your ssh is trying to login to root user (it is reading the /root/.ssh/ directory --- retry with hduser@$host in the script. — Rmano, Mar 21 '14 at 18:07
Thk you @Rmano . It works after copied `id_rsa` and `id_rsa.pub` under `/home/hduser/.ssh/` directory to `/root/.ssh/` directory — Eyüp Alemdar, Mar 21 '14 at 18:18
So my first comment is the solution... you are still logging into the "slave" root account, not hduser, because you are calling the script from root (maybe with sudo?) — Rmano, Mar 21 '14 at 18:20

score 0 · Accepted Answer · answered Mar 21 '14 at 18:20

Try to use the -i argument. From the man:

-i identity_file
         Selects a file from which the identity (private key) for RSA or
         DSA authentication is read.  The default is ~/.ssh/identity for
         protocol version 1, and ~/.ssh/id_rsa and ~/.ssh/id_dsa for pro-
         tocol version 2.  Identity files may also be specified on a per-
         host basis in the configuration file.  It is possible to have
         multiple -i options (and multiple identities specified in config-
         uration files).

Then you can specify the key to use for each host.

`-i` option works too. I pointed hduser ssh directory and it works without copying private key to root ssh directory. I changed this line: `ssh –t –o UserKnownHostsFile=/dev/null –o StrictHostKeyChecking=no -i "/home/hduser/id_rsa" -l ${USERNAME} ${host};` — Eyüp Alemdar, Mar 21 '14 at 18:51

score 0 · Answer 2 · answered Mar 21 '14 at 18:32

The script somehow looks to root directory to send private key. It works after copied id_rsa and id_rsa.pub under /home/hduser/.ssh/ directory to /root/.ssh/ directory.

sudo cp -av /home/hduser/.ssh/id_rsa /root/.ssh/
sudo cp -av /home/hduser/.ssh/id_rsa.pub /root/.ssh/

SSH asks password when invoke it in script

2 Answers2