Shell Script To Transfer Files From Amazon S3 Bucket.

Yesterday i have got a requirement from one of my friend for a shell script. He has a application running on AWS EC2. This application daily generates a report file (In zip format) and put it into a aws S3 bucket. He wants to copy this zip file to his local server and available in a common share folder for internal use. And also he wants to extract the zip file before it is in the share. So i am started working on this and created a shell script to satisfy his requirement and i added some extra functionalites for easy use.
The main functionalities are:

• Copy a latest uploaded file from S3 bucket.
• Extract this file before moving to common share.
• Log all the activites to a log file.
• Send an email report to admin with current session of the log (Not sending All the Logs).

For The working of the script you need to install s3cmd utility. It is a great tool for managing a aws S3 bucket. For installation of s3cmd read the README file.

Here is the script:

#!/bin/bash
#===============================================================================
#
#          FILE:
#
#         USAGE: 
#
#   DESCRIPTION:  This script is used to transfer latest zip file from AWS S3 to local directory then extract it into another directory.
#                 It will log all the actions and send a mail to admin.
#       OPTIONS:  ---
#  REQUIREMENTS:  This Script Requires s3cmd Utility. It is availble in sourceforge.net
#          http://sourceforge.net/projects/s3tools/files/s3cmd/1.0.1/s3cmd-1.0.1.tar.gz/download
#          BUGS:  ---
#         NOTES:  ---
#        AUTHOR:  arun sasidharan (), arunssasidhar@gmail.com
#       COMPANY:
#       VERSION:  1.0
#       CREATED:  Monday 18 July 2011 03:58:59  IST IST
#      REVISION:  ---
#===============================================================================
##Your S3 Bucket Name
S3_BUCKET=mybucket   

##Local Directory For downloading files from S3 Bucket          
LOCAL_DIR=/tmp/1/    

##Where to Log your activities during tranasfer         
LOG_FILE=/tmp/scriptlog

##Target location to extract the ZIP file    
ZIP_EXT_DIR=/tmp/var/Downloads/
    
##Admin Email For sending Log
ADMIN_EMAIL=arunssasidhar@gmail.com  

##Email Subject               
EMAIL_SUBJECT="S3 Transfer Status On"  #Should be in Quotes   
#*****************************************************************************************
#
#                               STOP EDITING FROM HERE DOWN!!!
#
#*****************************************************************************************
PATH=/usr/local/bin:/usr/bin:/bin:
DATE=$(date +"%d-%m-%Y_%Hh:%Mm")
TIME=$(date +"%Hh:%Mm")
echo "" >>$LOG_FILE
echo "$DATE" >>$LOG_FILE
#
[ -d $LOCAL_DIR ] || mkdir -p $LOCAL_DIR
[ -d $ZIP_EXT_DIR ] || mkdir -p $ZIP_EXT_DIR
#
#Main Functions
#This function is used to extract current sessions log from log file and send it to Admin
mail_me () {
 LIVE=$(cat $LOG_FILE | grep -n "$DATE" | tail -1 | cut -d":" -f 1)
 tail -n +$LIVE $LOG_FILE | mail -s "$EMAIL_SUBJECT $DATE" $ADMIN_EMAIL
}
#
#This function will send mail then exit with status 0
exit_0 () {
  mail_me
  exit 0
}
#
#This function will send mail then exit with status 1 (End up with error!)
exit_1 () {
  mail_me
  exit 1
}
#########################
## Get the Last uploaded File-name from S3 Bucket (Only One)
S3_OBJECT=$(s3cmd ls s3://$S3_BUCKET | sort | tail -1 | awk '{ print $4 }')
## Download the latest file into Local Directory
s3cmd get $S3_OBJECT $LOCAL_DIR 2>>$LOG_FILE                            
#########################
if [ $? -eq 0 ]
  then
      echo "$TIME : Transfer Completed Successfully" >>$LOG_FILE
      FILE=$(echo $S3_OBJECT | awk -F"/" '{print $NF}')             ## Fetch the file name from S3 URL
      echo "$TIME : Zip Extraction Started" >>$LOG_FILE
      unzip -nq "$LOCAL_DIR""$FILE" -d $ZIP_EXT_DIR 2>>$LOG_FILE    ## Unzip the downloaded file to extract Directory
               if [ $? -eq 0 ]
            then echo "$TIME : Zip Successfully Extracted To $ZIP_EXT_DIR" >>$LOG_FILE
                    else echo "$TIME : Zip Extraction Failed With Above Errors" >>$LOG_FILE
                         exit_1
               fi
      exit_0 
  else
      echo "$TIME : Transfer Failed with Above Errors" >>$LOG_FILE
      exit_1
fi
#########END#######

You can Download the script from here.