mjhjmtu

I wrote a script that shut down all servers in our environment. But if some server is not reachable to begin with or if it is already down, my script just hangs and nothing happens. How may I make it move ahead if some server is unreachable?

#!/bin/bash
#script for Shutting down all VM & BM.
Region=$1
user=$2
region_file_path="/region/$Region.txt"
host=`cat $region_file_path`
key_path="/root/.ssh/id_rsa_adminpod"
for i in $host
do
# echo "Shutting down Host in $Region with ip addrss $i"
 ssh -i $key_path -p 2222 $user@$i "sudo init 0" &> /dev/null
 if [ $? -ne 0 ]; then
 echo "$i is shutdown!"
 else
 echo "There is some issue, try again"
 exit 1
 fi
done

The simplest solution is to set connection timeout to some reasonable amount of time.

ssh -o ConnectTimeout=10 -i $key_path -p 2222 $user@$i "sudo init 0" &> /dev/null

10 seconds should be enough.

You could also use some other tools for automating tasks - i.e. Ansible.

Solution using Ansible is following.

0) Make sure you have enable SSH passwordless access between management node and nodes to be shutdown.

1) prepare simple inventory file with your nodes which should be shutdown. There is example content:

[local]
localhost ansible_connection=local

[nodes]
192.168.1.30
192.168.1.40

2) Run ansible shell module with your inventory file specified as parameter and shutdown command:

ansible -i /tmp/hosts -m shell -a "/usr/sbin/shutdown +1" nodes

The shutdown has 1 minute delay specified, so the connection isn't killed immediately. But maybe it's not needed.

This is just example, you may use any other command you want to run in parallel on multiple nodes.

If u have an 'not responding' dependency you could just go ahead without exit 1, with some more times to retry the ssh connection:

for i in $host
do
 counter=0
 while [ $counter -ne 3 ]; do
 # echo "Shutting down Host in $Region with ip addrss $i"
 ssh -o ConnectTimeout=10 -i $key_path -p 2222 $user@$i "sudo init 0" &> /dev/null
 if [ $? -ne 0 ]; then
 echo "$i is shutdown!"
 counter=3
 else
 echo "There is some issue, try again"
 counter=$(($counter+1))
 fi
 done
done