getting multiple issues while creating a script to update hostnames in /etc/hosts file?

Question

We've around 3000 VMs & 450 Physical servers which are Linux based servers (few of then ubuntu starting from 9.x & few of them are Susu starting 8.X & majority of them are RHEL starting from 4.x till 7.4) on all of them I need to add few hostname entries with IP details into their respective /etc/hosts files.

I've different users on each server with full sudoers access which I can use Hence I've created a CSV file with hostname, username & password format. which contains required details to log in. Filename is "hostname_logins.csv"

I need to upload a file (i.e. hostname_list to each of these servers and then update those same details in each of the servers host files.

I'll be running this script using one RHEL 6 server. (All of the other hosts are resolvable from this server & are reachable, I've confirmed it already.)

The script is working but it's asking for accepting the host key once and also asked for the password 2 times however the 3rd time it does not asked for a password it worked automatically I guess, but need to ensure it does not askes to accept the host key or passwords.:

#!/bin/bash
runing_ssh()
{
while read hostname_login user_name user_password
do ssh -vveS -ttq rishee:[email protected] "sudo -S -ttq < ./.pwtmp cp -p /etc/hosts /etc/hosts.$(date +%Y-%m-%d_%H:%M:%S).bkp && sudo -S bash -c 'cat ./hostname_list >> /etc/hosts' && rm -f ./.pwtmp ./hostname_list"
done < hostname_logins.csv
}

while read hostname_login user_name user_password
do  echo $user_password > ./.pwtmp
    cat ./.pwtmp
    scp -p ./.pwtmp ./hostname_list $user_name@$hostname_login:
    runing_ssh
done < hostname_logins.csv

I need to make this as a single script which will work on all these servers. thanks in advance.

before the while loop do IFS=, so you split up the data properly during the read command — MostWanted
– MostWanted, Commented Oct 18, 2017 at 10:05

Paul Hodges · Accepted Answer · 2017-10-24 13:39:30Z

2

+50

You are executing the original copy from /tmp with sudo, but nothing else.

while read hostname_login user_name user_password
do  echo $myPW >.pwtmp
    scp -p ./.pwtmp ./hostname_list $user_name:$user_password@$hostname_login:
    ssh -etS $user_name:$user_password@$hostname_login "sudo -S <.pwtmp cp -p /etc/hosts /etc/hosts.bkp && sudo -S <.pwtmp cat ./hostname_list >> /etc/hosts && rm -f ./.pwtmp ./hostname_list"
done < hostname_logins.csv

I dropped the explicit send to /tmp and the cp back to your home dir, and defaulted the location (to $user_name's home dir) by not passing anything to scp after the colon. Fix that if it doesn't work for you.

I created a password file for improved security and code reuse, and sent it along with the hosts list. I added a sudo -S to each relevant command, reading from the password file.

That [bash -c ...] syntax doesn't work on my implementation, so I took it out.

Hope that helps.

Update

Added -t to ssh call. Try that.

edited Oct 24, 2017 at 13:39

answered Oct 18, 2017 at 14:36

Paul Hodges

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17 Comments

Hrish Over a year ago

I tried your script but this is what the error I got

Hrish Over a year ago

[root@node2 ~]# ./script1.sh ssh: connect to host rishee port 22: No route to host lost connection rishee:[email protected]'s password: bash: .pwtmp: No such file or directory [root@node2 ~]#

Hrish Over a year ago

while read hostname_login user_name user_password do echo $myPW > .pwtmp scp -p ./.pwtmp ./hostname_list $user_name@$hostname_login: ssh -eS $user_name:$user_password@$hostname_login "sudo -S <.pwtmp cp -p /etc/hosts /etc/hosts.bkp && sudo -S <.pwtmp cat ./hostname_list >> /etc/hosts && rm -f ./.pwtmp ./hostname_list" done < hostname_logins.csv

Hrish Over a year ago

[root@node2 ~]# ./script1.sh [email protected]'s password: .pwtmp 100% 1 0.0KB/s 00:00 hostname_list 100% 122 0.1KB/s 00:00 rishee:[email protected]'s password: sudo: sorry, you must have a tty to run sudo [root@node2 ~]#

shellter Over a year ago

pluse uno for tech support (and helpful answer). Good luck to all.

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