Collection of Bash Scripts for Server Operations and Automation

1. Detect file consistency between two servers

#!/bin/bash
######################################
# Detect file consistency between two servers
#####################################
# Compare MD5 values of files in a directory on both servers

dir=/data/web
b_ip=192.168.88.10
# Generate MD5 list on server A
find $dir -type f | xargs md5sum > /tmp/md5_a.txt
# Generate MD5 list on server B via SSH
ssh $b_ip "find $dir -type f | xargs md5sum > /tmp/md5_b.txt"
scp $b_ip:/tmp/md5_b.txt /tmp
# Compare file names and MD5 values
for f in `awk '{print $2}' /tmp/md5_a.txt`
do
  if grep -qw "$f" /tmp/md5_b.txt
  then
    md5_a=`grep -w "$f" /tmp/md5_a.txt | awk '{print $1}'`
    md5_b=`grep -w "$f" /tmp/md5_b.txt | awk '{print $1}'`
    if [ $md5_a != $md5_b ]
    then
      echo "$f changed."
    fi
  else
    echo "$f deleted."
  fi
done

2. Scheduled file content clearing and size logging

#!/bin/bash
#################################################################
# Run hourly; at 00:00 or 12:00 clear file contents, otherwise log sizes
################################################################
logfile=/tmp/`date +%H-%F`.log
n=`date +%H`
if [ $n -eq 00 ] || [ $n -eq 12 ]
then
  for i in `find /data/log/ -type f`
  do
    true > $i
  done
else
  for i in `find /data/log/ -type f`
  do
    du -sh $i >> $logfile
  done
fi

3. Monitor network interface traffic and log it

#!/bin/bash
#######################################################
# Log network traffic every minute in bps
#######################################################
while :
do
  LANG=en
  logfile=/tmp/`date +%d`.log
  exec >> $logfile
  date +"%F %H:%M"
  sar -n DEV 1 59 | grep Average | grep ens33 | awk '{print $2,"\t","input:\t",$5*1000*8,"bps","
",$2,"\t","output:\t",$6*1000*8,"bps