Puppet manifest for multiple servers

Puppet supports regular expressions.

E.g.
Run puppet manifest on all the web servers:
node /^web.*$/ {
  class { 'server_web': }
}

Run on a few (db0-9)
node /^db[0-9]\..*$/ {
  class { 'server_db': }
}

bash script sum

Bash script exercise.
Add variable to the result of the sum.  E.g.
1 1 2 3 5 8 13 21, etc.


#!/bin/bash
x=1
y=1
ans=0

while [ $ans -lt 100 ]
#while true
do
  ans=$(( x + y ))
  echo $x + $y = $ans
  x=$y
  y=$ans
done

Bash "for loop"
How to ping multiple selected servers in selected multiple racks.

for rack in 1 3 4 6 9 {14..27}; do echo $rack; for server in {46..48}; do fping "serv"$server"rack"$rack |grep unreachable |tee -a /tmp/down; done; done

Number of hits from server in bash

Let's say I have a list of servers and I want to calculate how many hits did I have from "client.com" on April 28, 2014

#!/bin/bash
total=0

for server in $(cat server_list)
  do
    echo $server
    echo "Current count = "$total
    servercount=$(ssh $server "zcat /var/log/httpd/access.2014-04-28.log.gz |grep client.com |wc -l")
    echo "Server count ="$servercount
    total=$(($total + $servercount))
done

echo "Total count = "$total