[SOLVED] using getopts with flags to backup cronjobs

michaelk · 06-24-2016, 11:55 AM

In addition, $location will never be blank. It will either be set to bkuplocation or defined as a argument. In fact you only need one such variable just like your $method variable.

Code:

#parameter expansion for $host-$user
file="$hostname-$user"
userfile=${file##*-}

for users in "$host-*"; do
    crontab $user < $bkuplocation/$userfile
done

Have you tested this code yet? This statement "userfile=${file##*-}" will strip the user from the string $host-$user but as written $hostname and possibly $user has never been defined. Your $user variable will be $host-$user for all matches in the directory. I would probably use something else in the restore section so you do not get confused with the user entered $user variable.

You need to extract the username in the loop. As suggest by others I would use echo to verify the commands were correct while you were debugging your code. And note at the moment it isn't

Code:

echo "crontab $user < $bkuplocation/$userfile"

Here is some good information.
http://mywiki.wooledge.org/BashPitfalls

linuxnewbie0101 · 06-24-2016, 12:59 PM

yes i have tested the code, everything works as expected, excepted for the new error handling block.

the parameter expansion is intent to strip the filename when it restores. when backup occur it adds $host in front of the user. but when calling restore with -u user, the file on $bkuplocation will be $host-$user so i wanted to remove $host when restore.

can you give me a hint on what im doing wrong here.

Code:

if [[ $method='backup' && $location=$bkuploacation ]]; then
  if [[ ! -z $user && $user != ls $cron_source | grep $user ]]; then
    echo " ERROR: no cronjob found for $host $user."
    exit 1
  fi
fi

can i set something like

Code:

test="ls $cron_source | grep $user"

if [[ $method='backup' && $location=$bkuploacation ]]; then
  if [[ ! -z $user && $user != $test ]]; then
    echo " ERROR: no cronjob found for $host $user."
    exit 1
  fi
fi

TY

update:

maybe

Code:

if [[ $method='backup' && ! -z $user ]]; then
  if [[ $user != "`ls $cron_source | grep $user`" ]]; then
    echo " ERROR: no cronjob found for $host $user."
    exit 1
  fi
fi

michaelk · 06-24-2016, 01:12 PM

I know what you are trying to accomplish. I have not tested your code and it seems you do not always post the latest version so I can only go by what I see.

I do not see why the value of $location or $bkuplocation matters for determining a valid user. Yes, what you posted using the $test case will work.

linuxnewbie0101 · 06-24-2016, 01:27 PM

most updated code

Code:

#!/bin/bash -e

bkuplocation="/systems/homes/cronjobs_bk"
cron_source="/var/spool/cron/crontabs"
host=$(hostname -s)

location=$bkuplocation
method='backup'
#comment the above 2 lines if -m is a require at later time

#Help function
function show_help {
  echo " Command line switches are -m , -p & -u"
  echo " -m  --Sets the value for option to backup or restore (backup/restore). Default to backup"
  echo " -p  --Sets the path to backup from and restore to. Default to $bkuplocation"
  echo " -u  --Sets the user jobs to backup. Default to all"
  echo " -h  --Displays this help message. No further functions are performed."
  exit 1
}

#Uncomment this block to ensure required arguments
#=======================================================================
#Check the number of arguments. If none are passed, print help and exit.
#numargs=$#
#if [ $numargs -eq 0 ]; then
#  show_help
#fi
#=======================================================================

# Start getopts code
while getopts :m:p:u:h options; do
  case $options in
    m) 
      method=$OPTARG
      ;;
    p) 
      location=$OPTARG
      ;;
    u)
      user=$OPTARG
      ;;
    h)
      show_help
      ;;
  \?) echo -e "Option $OPTARG not allowed."/n
      show_help
      ;;
  esac
done




#Error checking for $bkuplocation and $location
if [[ ! -d $bkuplocation ]]; then
  echo " ERROR: default backup location does not exist. Please make sure $bkuplocation is available or use -p to specify backup location."
  exit 1
fi

if [[ ! -z $location && ! -d $location ]]; then
  echo " ERROR: Specified location does not exist. Please provide another location or use default location."
  exit 1
fi

#Error checking for user backup
if [[ $method='backup' && ! -z $user ]]; then
  if [[ $user != $(ls $cron_source | grep $user) ]]; then
    echo " ERROR: no cronjob found for $host $user."
    exit 1
  fi
fi

#Error checking for user restore
if [[ $method='restore' && -z $location ]]; then
  if [ ! -z $user && $host-$user != $(ls $bkuplocation | grep $host-$user) ]; then
    echo " ERROR: no cron backup found for $host $user."
    exit 1
  fi
fi

if [[ $method='restore' && ! -z $location ]]; then
  if [ ! -z $user && $user != $(ls $location | grep $user) ]; then
    echo " ERROR: no backup crontab jobs found for $host $user."
    exit 1
  fi
fi

#parameter expansion for $host-$user
file="$hostname-$user"
userfile=${file##*-}

case $method in
  backup)
    if [[ -z $location && -z $user ]]; then
      cd $cron_source
      for users in *; do 
        crontab -l -u $users > $bkuplocation/$host-$users
      done
    elif [[ ! -z $location && ! -z $user ]]; then
        crontab -l -u $user > $location/$host-$user
    elif [[ -z $location && ! -z $user ]]; then
        crontab -l -u $user > $bkuplocation/$host-$user
    elif [[ ! -z $location && -z $user ]]; then
      cd $cron_source
      for users in *; do 
        crontab -l -u $users > $location/$host-$users
      done
    else 
      show_help
    fi
  ;;

  restore)
    if [[ -z $location && -z $user ]]; then
      cd $bkuplocation
      for users in "$host-*"; do
        crontab $users < $bkuplocation/$userfile
      done  
    elif [[ ! -z $location && ! -z $user ]]; then
        crontab $user < $location
    elif [[ ! -z $location && -z $user ]]; then
      cd $location
      for users in *; do 
        crontab $users < $location
      done
    elif [[ -z $location && ! -z $user ]]; then
        crontab $user < $bkuplocation/$host-$user
    else
      show_help
    fi
  ;;
esac

exit 0

keefaz · 06-24-2016, 01:36 PM

You could simplify:

Code:

if [[ $user != $(ls $cron_source | grep $user) ]]; then

With:

Code:

if [[ ! -f $cron_source/$user ]]; then

linuxnewbie0101 · 06-24-2016, 02:28 PM

ok im hitting a wall again, this time its a strange one.

here are my latest code which works perfectly w/o error checking block.

this is the error message when i tried to run backup on root

ERROR: no backup crontab jobs found for mysql11 root.

it is triggering a error check for restore.

but im not running restore.

Code:

#!/bin/bash -ex

bkuplocation="/systems/homes/cronjobs_bk"
cron_source="/var/spool/cron/crontabs"
host=$(hostname -s)

location=$bkuplocation
method='backup'
#comment the above 2 lines if -m is a require at later time

#Help function
function show_help {
  echo " Command line switches are -m , -p & -u"
  echo " -m  --Sets the value for option to backup or restore (backup/restore). Default to backup"
  echo " -p  --Sets the path to backup from and restore to. Default to $bkuplocation"
  echo " -u  --Sets the user jobs to backup. Default to all"
  echo " -h  --Displays this help message. No further functions are performed."
  exit 1
}

#Uncomment this block to ensure required arguments
#=======================================================================
#Check the number of arguments. If none are passed, print help and exit.
#numargs=$#
#if [ $numargs -eq 0 ]; then
#  show_help
#fi
#=======================================================================

# Start getopts code
while getopts :m:p:u:h options; do
  case $options in
    m) 
      method=$OPTARG
      ;;
    p) 
      location=$OPTARG
      ;;
    u)
      user=$OPTARG
      ;;
    h)
      show_help
      ;;
  \?) echo -e "Option $OPTARG not allowed."/n
      show_help
      ;;
  esac
done

#Error checking for $bkuplocation and $location
if [[ ! -d $bkuplocation ]]; then
  echo " ERROR: default backup location does not exist. Please make sure $bkuplocation is available or use -p to specify backup location."
  exit 1
fi

if [[ ! -z $location && ! -d $location ]]; then
  echo " ERROR: Specified location does not exist. Please provide another location or use default location."
  exit 1
fi

#Error checking for user backup
if [[ $method='backup' && ! -z $user ]]; then
  if [[ ! -f "$cron_source/$user" ]]; then
    echo " ERROR: no cronjob found for $host $user."
    exit 1
  fi
fi

#Error checking for user restore
if [[ $method='restore' && -z $location ]]; then
  if [[ ! -z $user && ! -f "$bkuplocation/$host-$user" ]]; then
    echo " ERROR: no cron backup found for $host $user."
    exit 1
  fi
fi

if [[ $method='restore' && ! -z $location ]]; then
  if [[ ! -z $user && ! -f "$location/$user" ]]; then
    echo " ERROR: no backup crontab jobs found for $host $user."
    exit 1
  fi
fi

#parameter expansion for $host-$user
file="$hostname-$user"
userfile=${file##*-}

case $method in
  backup)
    if [[ -z $location && -z $user ]]; then
      cd $cron_source
      for users in *; do 
        crontab -l -u $users > $bkuplocation/$host-$users
      done
    elif [[ ! -z $location && ! -z $user ]]; then
        crontab -l -u $user > $location/$host-$user
    elif [[ -z $location && ! -z $user ]]; then
        crontab -l -u $user > $bkuplocation/$host-$user
    elif [[ ! -z $location && -z $user ]]; then
      cd $cron_source
      for users in *; do 
        crontab -l -u $users > $location/$host-$users
      done
    else 
      show_help
    fi
  ;;

  restore)
    if [[ -z $location && -z $user ]]; then
      cd $bkuplocation
      for users in "$host-*"; do
        crontab $users < $bkuplocation/$userfile
      done  
    elif [[ ! -z $location && ! -z $user ]]; then
        crontab $user < $location
    elif [[ ! -z $location && -z $user ]]; then
      cd $location
      for users in *; do 
        crontab $users < $location
      done
    elif [[ -z $location && ! -z $user ]]; then
        crontab $user < $bkuplocation/$host-$user
    else
      show_help
    fi
  ;;
esac

exit 0

and here is the output:

Code:

~$ sudo ./getopt.sh -u root

+ bkuplocation=/systems/homes/cronjobs_bk
+ cron_source=/var/spool/cron/crontabs
++ hostname -s
+ host=mysql11
+ location=/systems/homes/cronjobs_bk
+ method=backup
+ getopts :m:p:u:h options
+ case $options in
+ user=root
+ getopts :m:p:u:h options
+ [[ ! -d /systems/homes/cronjobs_bk ]]
+ [[ ! -z /systems/homes/cronjobs_bk ]]
+ [[ ! -d /systems/homes/cronjobs_bk ]]
+ [[ -n backup=backup ]]
+ [[ ! -z root ]]
+ [[ ! -f /var/spool/cron/crontabs/root ]]
+ [[ -n backup=restore ]]
+ [[ -z /systems/homes/cronjobs_bk ]]
+ [[ -n backup=restore ]]
+ [[ ! -z /systems/homes/cronjobs_bk ]]
+ [[ ! -z root ]]
+ [[ ! -f /systems/homes/cronjobs_bk/root ]]
+ echo ' ERROR: no backup crontab jobs found for mysql11 root.'
 ERROR: no backup crontab jobs found for mysql11 root.
+ exit 1

michaelk · 06-24-2016, 03:16 PM

Syntax error. The equals sign needs to be separated by a space.

if [[ $method = 'restore' ... ]]

Code:

    for users in "$host-*"; do
        crontab $users < $bkuplocation/$userfile
      done

All you need to install jobs by file is crontab <file>. In your code to restore all, the loop will install all found files to the user that runs the script. Which if run by root will overwrite its jobs unintentionally. "< $bkuplocation/$userfile" is not required and in addition as I tried to explain earlier $userfile will be undefined.

keefaz · 06-24-2016, 04:16 PM

From debug output:

Code:

+ [[ ! -d /systems/homes/cronjobs_bk ]]
+ [[ ! -z /systems/homes/cronjobs_bk ]]
+ [[ ! -d /systems/homes/cronjobs_bk ]]

$bkuplocation and $location are redundant, make your life simpler by using just one variable for the backup directory.
Variable = value can vary, eg can store default location or custom location

If you want to test existence of custom location, better do it at the option setting

Code:

while getopts :m:p:u:h options; do
  case $options in
    ...
    p) 
      bkuplocation=$OPTARG
      if [[ ! -d $bkuplocation ]]; then
         echo " ERROR: Specified location does not exist."
         exit 1;
      fi
      ;;

Just in my opinion of course

linuxnewbie0101 · 06-28-2016, 03:00 PM

Gents, how can i implement a log file to see everything that is going on with the script with timestamps?

exec >> $log_file 2>&1 && tail $log_file

?

i've since added

echo -e $timestamp >> $logfile
exec >> $logfile 2>&1 && tail $logfile

can i high-light the timestamp in my logfile?

linuxnewbie0101 · 06-29-2016, 01:49 PM

ok i think im down to the last part of this.

i am still having problem when restore and the part im stuck is the for loop to restore

Code:

  restore)
    if [[ -z $user ]]; then						#restore for all users from default backup location
      cd $bkuplocation
      for users in "$host-*"; do
        crontab $users < $bkuplocation/$host-$users
      done  
    elif [[ ! -z $user ]]; then						#restore with user input -p and -u
        crontab $user < $bkuplocation/$host-$user
    else
      show_help								#show Help function if not recognized
    fi
  ;;

not sure how i can loop the files from $host-$user to $user......

michaelk · 06-29-2016, 02:45 PM

Look keefax and mine my previous posts.

Check out the man page for crontab. The syntax to restore a user's crontab is "crontab file". Similar to your backup loop you need to specify the user name in the restore loop.

keefax provided the code to extract the user name from the backup file $host-$user which needs to be inside the loop and has been modified a bit to fit your code.

Code:

      for users in "$host-*"; do
        username=${users##*-}
        crontab -u $username $users
      done

Untested but should be enough to get you going and to help you figure out the rest.

linuxnewbie0101 · 06-29-2016, 05:22 PM

gents/ladies,

here are my latest code. stuck on restoring all users or individual users. not sure where im doing wrong, the outputs are showing what i want it to do.

please provide any feedbacks or errors that just pops up for you. been looking at this for days now and everything seems the same to me now. =(

TY

Code:

#!/bin/bash -ex
# This script by default is designed to backup all users crontab on host
# and must be run as root user.
# Use optional flags to set values other than default.
# default usage: script.sh  
# optional usage: script.sh -m (backup||restore) -p (desire path) -u (user)
# see Help function for more detail on setting optionals.    

bkuplocation="/systems/homes/cronjobs_bk"				#default backup location
cron_source="/var/spool/cron/crontabs"					#default crontab location
host=$(hostname -f)							#host FQDN
logfile=$bkuplocation/logs/crontabs.log
timestamp=`date "+%Y.%m.%d %H:%M:%S"`

#location=$bkuplocation							#defaults to backup location if no user input for -p
method='backup'								#setting default method to backup
#comment the above 2 lines if -m is a require at later time

# Make sure only root can run this script
if [ "$(id -u)" != "0" ]; then						# must run script as root
  show_help
  exit 1
fi

#checking for $bkuplocation. 
if [[ ! -d $bkuplocation ]]; then
  umask 007								#setting umask to root RW only
  mkdir $bkuplocation
  chgrp -R opsdr $bkuplocation						#create $bkuplocation if it does not exist.
fi

#checking for $logfile location. 
if [[ ! -d $bkuplocation/logs ]]; then
  mkdir $bkuplocation/logs						#create $bkuplocation if it does not exist.
  chgrp -R opsdr $bkuplocation/logs
  touch $logfile
fi

#echo -e $timestamp >> $logfile
#exec >> $logfile 2>&1 && tail $logfile

#Help function
function show_help {
  echo " script must be run as root. "
  echo " default usage : scriptname.sh -m (backup||restore) -p (location) -u (user) "
  echo " Command line switches are -m , -p & -u "
  echo " -m  --Sets the value for option to backup or restore. Defaults to backup. "
  echo " -p  --Sets the path to backup from and restore to. Defaults to $bkuplocation "
  echo " -u  --Sets the user's job for backup. Defaults to all "
  echo " -h  --Displays this help message. No further functions are performed. "
  exit 1
}

#Uncomment this block to ensure required arguments
#=======================================================================
#Check the number of arguments. If none are passed, print help and exit.
#numargs=$#
#if [ $numargs -eq 0 ]; then
#  show_help
#fi
#=======================================================================

# Start getopts code
while getopts :m:p:u:h options; do
  case $options in
    m) 
      method=$OPTARG
      ;;
    p) 
      bkuplocation=$OPTARG
      ;;
    u)
      user=$OPTARG
      ;;
    h)
      show_help
      ;;
  \?) echo -e "Option $OPTARG not allowed."/n
      show_help
      ;;
  esac
done

#Error checking for user input $location
#if [[ $location != $bkuplocation && ! -d $location ]]; then
#  echo " ERROR: Specified location $location does not exist. Please verify location or use default location by removing -p argument. "
#  exit 1
#fi

if [[ ! -d $bkuplocation ]]; then
  echo " ERROR: Specified location $location does not exist. Please verify location or use default location by removing -p argument. "
  exit 1
fi

#Error checking for user input user backup
if [[ $method = 'backup' && ! -z $user ]]; then
  if [[ ! -f "$cron_source/$user" ]]; then
    echo " ERROR: no cronjob found for $user on $host."
    exit 1
  fi
fi

#Error checking for user restore
#if [[ $user != $(ls $cron_source | grep $user) ]]; then			#verify user have jobs on $host before restore.
#  echo " ERROR: $user currently do not have any jobs on $host ."
#  exit 1
#fi

#Error checking for user restore
#if [[ $method = 'restore' ]]; then
#  if [[ ! -z $user && ! -f "$bkuplocation/$host-$user" ]]; then
#    echo " ERROR: no cron backup found for $user on $host ."
#    exit 1
#  fi
#fi

#if [[ $method = 'restore' && -d $bkuplocation ]]; then
#  if [[ ! -z $user && ! -f "$bkuplocation/$user" ]]; then
#    echo " ERROR: no backup crontab jobs found for $host $user."
#    exit 1
#  fi
#fi

#parameter expansion for $host-$user
#file="$host-$user"
#userfile=${file##*-}

case $method in
  backup)
    if [[ -z $user ]]; then						#default backup, no user input
      cd $cron_source
      for users in *; do 
        crontab -l -u $users > $bkuplocation/$host-$users
      done
    elif [[ ! -z $user ]]; then						#backup with user input -p and -u
        crontab -l -u $user > $bkuplocation/$host-$user
    else 
      show_help								#show Help function if not recognized
    fi
  ;;

  restore)
    if [[ -z $user ]]; then						#restore for all users from default backup location
      cd $bkuplocation
      for users in "$host-*"; do
        username=${users##*-}
        crontab $username $user
      done  
    elif [[ ! -z $user ]]; then						#restore with user input -p and -u
        crontab $user < $bkuplocation/$host-$user
    else
      show_help								#show Help function if not recognized
    fi
  ;;

esac

exit 0

michaelk · 06-29-2016, 05:36 PM

What happened when when you tried my code i.e.

Code:

crontab -u $username $users

linuxnewbie0101 · 06-29-2016, 06:09 PM

Quote:

Originally Posted by michaelk

What happened when when you tried my code i.e.

Code:

crontab -u $username $users

ambiguous redirect at line 142.

keefaz · 06-29-2016, 06:52 PM

Why use case for just 2 conditional statments at the end, using if else is enough, it's a matter of style though

You have to remove the quotes in for loop near line 145, correct a small typo ($user instead of $users) and correct command to restore a crontab should be ' crontab -u username file ' as michaelk suggested

So:

Code:

restore)
    if [[ -z $user ]]; then						#restore for all users from default backup location
      cd $bkuplocation
      for users in $host-*; do
        username=${users##*-}
        crontab -u $username $users
      done  
    elif
...

Maybe choose a better variable name for $users here, like $userFile