Traverse through list of servers using ssh non-interactively.

Shell Programming and Scripting
1

I have 300 servers listed in servers.txt

I motto is to check if my id "user1" has sudo privileges on the 3000 servers. I m using sudo -l to check if I have privileges or not. If wish to check this either non-interactively; if not; interactively.

Below is the script I wrote:

newinput="server.txt"
while IFS= read -r var
do
echo " Variable is:"$var
sshpass -p mypassword ssh -t user1@$var 'echo "mypassword" | sudo -S -l; echo $?; exit'
 
done < "$newinput"

However; after returning non-zero for echo $? the script does not traverse through the list and checks only the first server.

Could you propose a feasible solution to the problem ?

2

Instead of this "pull" approach by polling all these servers; have you considered "pushing" the same data via crontab scripts?

3

There is only one way connection from the server i m running the script to the 300 servers. Hence my approach. Please help.

4

Sorry, I cannot help you.

It is a much better solutions, in my view, to run a cron script on each server and send the data back to a repository. Or at a minimum to run a cron script and to stage the data before it is "polled" from somewhere.

If you don't have control of your architecture and network systems engineering, I can't help you.

Perhaps someone else will ?

5

You would need to use a different file descriptor, since descriptor 0 (stdin) is needs by ssh.

while IFS= read -r var <&3
do
  [..]
done 3< "$newinput"
6

I know different systems may have different policies with respect to sudo-er lists, but would it be possible to check to see if you are in the sudo group on each system?

for h in $LIST_OF_HOSTS
do
printf "%s: %s\n" "${h}" "$(ssh ${uname}@{h} /usr/bin/groups)" 
done | grep sudo

This only works for systems that put users in the sudo, group and use the sudo group in the sudoers file, which will be the default, I imagine, but a decent, security-minded sysadmin may set up an alternative policy. Having said that, I once installed a SUSE (possibly openSUSE?) system where the user needed the root password to use sudo.

Andrew