0

To login into my database the following are the steps I follow every time:

ssh unix_id@something.com 
password: 

Once I am connected, I log in into a local database server in the same terminal:

ssh database_name 
password:

Then I do an su as:

su - appuser

And next I do the actual connection to sqlplus:

sqlplus ..

I am trying to automate this using a unix script, but I am not able to figure out the following:

  1. how do I use 2 SSH in the same script
  2. I could go as far as "ssh database_name" and entered the password, but then control returns to the terminal and rest of the script is not executed
  3. I understand that after the second ssh I have to pass in the rest of the commands, starting with the su command as a parameter; but I don't know how to do the same.
  • you have to configure ssh-keygen so that you can login. – Mongrel Mar 8 '16 at 17:06
  • Are you using passwordless login (i.e. using keypairs with empty passphrases) or are you trying to hardcode passwords into the scripts ? Or you are just typing the password as they get asked ? – MelBurslan Mar 8 '16 at 17:07
  • Thank you for your comment :) I am typing the password as they are asked. I have to do this as the passwords keep getting changed often and this script will be used by people having different unix ids and passwords; so I am not sure if I can use ssh-keygen. – user1741642 Mar 8 '16 at 17:40
0

My approach to this would be two-fold. One, configure password-less keyed login for SSH via ssh-keygen as @Avinash mentions in a comment. Second, make use of expect to step through the two SSH sessions and the launch of sqlplus, then return control to the terminal.

  • Thank you John. Can you give a small example for this, since I am new to unix and not sure about how to use the expect to step through the SSH sessions. I did try to use the expect command and using expect *$ and then giving the password, but I was getting authentication failed everytime. – user1741642 Mar 8 '16 at 17:43
  • It would be helpful if you could please put an example or point me someplace where this is already answered. – user1741642 Mar 8 '16 at 17:45
0

Something like this, plus passphrase-less pubkey auth should do the trick:

# create an ssh connection for tunneling only, in the background (this assumes tunneling is allowed... usually is)
ssh -N -L 9999:database_name:22 unix_id@something.com &
pid=$!

# connect to the 2nd machine directly, using the tunnel, also run only the sqlplus command. (this assumes sudo is installed)
ssh -oPort 9999 localhost sudo -u appuser sqlplus ..

kill $pid

The first command can be replaced by a special config in ~/.ssh/config. Here's an example:

Host mytunnel
    User unix_id
    Hostname something.com
    LocalForward 9999 localhost:22

Host sqlviatunnel
    User unix_id
    Hostname localhost
    Port 9999
    ProxyCommand ssh -q -W %h:%p mytunnel

And then

ssh sqlviatunnel

Rename sqlviatunnel to something shorter.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.