Visit Our UNIX and Linux User Community


Prevent wrong user from using shell script for multiple remote servers


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Prevent wrong user from using shell script for multiple remote servers
# 1  
Old 06-08-2011
Question Prevent wrong user from using shell script for multiple remote servers

Hi,

I am running a shell script from a central server to multiple remote servers using the following code:

Code:
application_check()
{
# Linux/UNIX box with ssh key based login
SERVERS=`cat /tmp/server-details`
# SSH User name
USR="user"
# create new file
> /tmp/abc.log
 
# connect each host and pull up user listing
for host in SERVERS
do
echo "--------------------------------" >> /tmp/abc.log
echo "HOST: $host " >> /tmp/abc.log
echo "--------------------------------" >> /tmp/abc.log
 
ssh -q $USR@$host '
       command 1
      command 2
      echo "EOF"
         ' >> /tmp/abc.log
}

Now, when someone runs this script using another user for which the ssh keys are not shared in the remote servers, the script gets stuck initially asking for authentication or password.

Code:
 The authenticity of host '10.1.1.1 (10.1.1.1)' can't be established.
RSA key fingerprint is 32:f8:ac:a4:af:ab:dc:3a:02:29:e8:0e:36:2d:06:e4.
Are you sure you want to continue connecting (yes/no)?

or
Code:
 $hosts's password:

I want to have a check within my script that if it encounters the above two outputs on screen, then it should exit the script by giving an error.

I cannot use expect.

Please suggest a resolution.

Thanks in advance//
# 2  
Old 06-08-2011
Use the following: first check for the existence of the key in the known_hosts file and if it is there then run ssh with publickey as the only authentication option:
Code:
if grep "$host" ~/.ssh/known_hosts > /dev/null; then
   ssh -q -o PreferredAuthentications=publickey $USR@$host '
      command 1
      command 2
      echo "EOF"
    ' >> /tmp/abc.log
fi

ssh will exit with an error exit code (!=0) if the publickey authentication is not possible. Your script will not be interrupted.
This User Gave Thanks to ciupinet For This Post:
# 3  
Old 06-08-2011
Hammer & Screwdriver

Thanks, The code given by you resolves the issue.

Previous Thread | Next Thread
Test Your Knowledge in Computers #272
Difficulty: Easy
Alan Turing, while working at Bletchley, occasionally ran the 40 miles to London when he was needed for meetings there.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Shell script to ping multiple servers

Hi I did the following script to ping multiple servers, but I keep on receiveing duplicate emails for one server that is down: #!/bin/bash date cat /var/tmp/servers.list | while read output do ping -c 1 "$output" > /dev/null if ; then echo "node $output is up" else ... (10 Replies)
Discussion started by: fretagi
10 Replies

2. Shell Programming and Scripting

Shell script for remote servers

Hi , I have written a small script : set -x #!/bin/ksh for i in `cat /tmp/list` ( list contains remove servers ) do ssh -t $i << EOF uname -a cd ~user echo "Enter the dir >" read dir path=`ll -ld /home/user/"$dir"` if ; then echo "Dir exists " read rm $path else echo "no such... (9 Replies)
Discussion started by: kpatel786
9 Replies

3. Shell Programming and Scripting

Running set of commands in remote servers in shell script

Hi Wishing to all. I am very new joined in an organization as a unix system administrator. I need a help in preparing a script for a report. i have a file contains all of the linux/ubuntu servers line by line around 140 servers. vi servers.txt nh01 nh02 nh03 bh01 bh04 - - :wq (3 Replies)
Discussion started by: kumaraswamy
3 Replies

4. Shell Programming and Scripting

Script To Delete User Accounts On Multiple Servers

Hello All, The servers in question are AIX/Unix servers. I was hoping to find a scripting solution where I could use one server as a jump server and run a script that would check each server for a user account (the source file for the user accounts would be a text file or csv file) , and delete... (4 Replies)
Discussion started by: k45bryant
4 Replies

5. Shell Programming and Scripting

Remote login and running a script on multiple servers

Hi all, I am baffled on this. Solaris Irix system.:confused: I have 4 servers all connected to one another, :b: I need to write a script line that would login on to server 1-3 ($HOST) start a script in the back ground and log off while the back ground script runs over a length of time.:eek: ... (10 Replies)
Discussion started by: weddy
10 Replies

6. Solaris

Remote execution of a local script on multiple servers

So I have a scriptlet called solaris_command: for i in \ server1 server2 server3 do echo $i ssh $i $1 echo "" done I then use that as a command in multiple scripts to allow for data gathering for all virtual hosts in the environment thusly: solaris_command "cat... (3 Replies)
Discussion started by: os2mac
3 Replies

7. Shell Programming and Scripting

Shell script to connect to multiple ssh servers

Hello, I have access to several linux servers (mostly centos based) located in a DC in another country. from day to day I need to login to each of them to do some work (they dont have gui/window manager installed, I work only from console), or even to just do a check like df -h for disc usage.... (3 Replies)
Discussion started by: MaRiOsGR
3 Replies

8. UNIX for Dummies Questions & Answers

Running the same remote script on multiple servers

Experts, Im trying to remote into a server, run a script that resides on that server and capture the information displayed & store in a local file. I struggled with this yesterday & finally that script is working now. Now, here is a scope creep and the script that I wrote for 1 remote... (2 Replies)
Discussion started by: OMLEELA
2 Replies

9. Shell Programming and Scripting

script to change passwords for the same user on multiple servers

I am trying to write a script to change passwords for the same user on multiple servers. My environment runs purely ssh / scp not rsh / rcp and therefore coping using rcp is not an option. I have been playing with expect to perform tasks but think there must be a better way. Has anyone got... (7 Replies)
Discussion started by: stolz
7 Replies

10. Shell Programming and Scripting

unix shell script which inserts some records into a file located in remote servers...

All, I need to write an unix shell script which inserts some records into a file located in remote servers. * Get the input from the user and insert according the first row. It should be in ascending order. 123451,XA,ABA 123452,XB,ABB 123453,XC,ABC 123455,XE,ABE 123456,XF,ABF 123458,XG,ABG... (2 Replies)
Discussion started by: techychap
2 Replies

Featured Tech Videos