I am trying to add free and used memory (so that i can compute percentage used)of remote nodes using shell script. I use the openssh-server,expect tool and ssh script.
1)login.txt (info of nodes):
ip1|username|password
ip2|username|password
.
.
.
3)sshlogin.sh
#!/bin/bash
FILE=login.txt
CONNECT=./sshlogin.exp
exec 0<$FILE
while read line
do
MyServer=$(echo $line | cut -d'|' -f1)
MyUser=$(echo $line | cut -d'|' -f2)
MyPassword=$(echo $line | cut -d'|' -f3)
$CONNECT $MyPassword $MyServer MyUser>$MyServer.txt
grep buffers/cache $MyServer.txt>mem.txt
MEMFILE=mem.txt
exec 0<$MEMFILE
while read line
do
used=$(echo $line | cut -d' ' -f3)
free=$(echo $line | cut -d' ' -f4)
total='expr $used + $free' #This is my headache can't see
# what is the problem
echo $used
echo $free
echo $total
done
done
3)sshlogin.exp:
#!/usr/bin/expect -f
# set Variables
set password [lrange $argv 0 0]
set ipaddr [lrange $argv 1 1]
set username [lrange $argv 2 2]
set timeout -1
# now connect to remote UNIX box (ipaddr) with given script to execute
spawn ssh $username@$ipaddr
match_max 100000
# Look for passwod prompt
expect "*?assword:*"
# Send password aka $password
send -- "$password\r"
# send blank line (\r) to make sure we get back to gui
#send -- "\r"
expect "$"
send -- "free -k\r"
expect "$"
send -- "exit\r"
expect "logout"
I am using this to determine if the nodes should be turned off if the memory utilization is below certain threshold.