How to auto login (ssh) to every server and search logs.

For example: if the environment set up like following
There are 9 boxes from usppre11 to usppre19
logs are stored in /tmp
$ ls -ltr
-rw-r--r--   1 admin atg      16455232 Sep 28 17:15 wls_XXX_AdminServer_XXX_stdout.txt.4728104734
-rw-r--r--   1 admin atg      17439042 Sep 29 08:44 wls_XXX_AdminServer_XXX_stdout.txt.1628171655
-rw-r--r--   1 admin atg      20182090 Sep 29 16:31 wls_XXX_AdminServer_XXX_stdout.txt.4629084624
-rw-r--r--   1 admin atg      26107020 Oct  1 15:04 wls_XXX_AdminServer_XXX_stdout.txt.3329163306
-rw-r--r--   1 admin atg      41899784 Oct  6 13:31 wls_XXX_AdminServer_XXX_stdout.txt.1501171516

grepall.sh

#!/usr/bin/expect -f
#!/bin/bash

# search string
set searchstring  [lrange $argv 0 0]
# month MMM format example: Aug
set month [lrange $argv 1 1]
# day dd example  28 or 1
set day [lrange $argv 2 2]
# to list lines - l or just to know the count c
set arg1 [lrange $argv 3 3]
# set password
set pass wlsview
if {${arg1} == "c"} {
  set cmd "grep -i ${searchstring} \$(ls -ltr | grep -i '${month}.*${day}.*wls.*AdminServer.*stdout' | sed -n 's/^.*wls/wls/p') | wc -l"
}
if {${arg1} == "l"} {
  set cmd "grep -i ${searchstring} \$(ls -ltr | grep -i '${month}.*${day}.*wls.*AdminServer.*stdout' | sed -n 's/^.*wls/wls/p')"
}
for {set i 1} {$i < 10} {incr i 1} {
 spawn ssh -o StrictHostKeyChecking=no username@usppre1$i
 expect -re "Password:"
 send "${pass}\r"
 send "cd /tmp\r"
 send "${cmd}\r"
 send "\r"
 send "\r"
 send "exit\r"
 expect eof
}