Re: Help with script - doesn't work properly from cron

[Erik Olof Wahlstrom]

Thanks everyone for your pointers - I ended up with this:

#!/bin/bash
BACKUP_DIR="/media/disk/AUTOMATED_BACKUPS/DB_DAILY"

CURRENT_DIR=$BACKUP_DIR/`date +%d`

DATABASES="$(mysql -uroot -pNewSecretPw -Bse 'show databases')"
echo 'Backing up databases: '$DATABASES

cd /
rm -rf "$CURRENT_DIR"
mkdir -p "$CURRENT_DIR"
cd "$CURRENT_DIR" || exit 1

for DB in $DATABASES
do
        mysqldump -uroot -pNewSecretPw "$DB" | bzip2 > "${DB}_$(date
+%Y-%m-%d_%H:%M).sql.bz2"
done

exit 0

It worked on the first manual run - keeping my fingers crossed for tonight!
:-P


Bob Proulx wrote:
> 
> Greg Wooledge wrote:
>> Erik Olof Wahlstrom wrote:
>> >         /usr/bin/mysqldump -uroot -pHardAsMySql321 "$DB" | bzip2 >
>> > "$DB"_`date +%Y-%m-%d_%k.%M`".sql.bz2"
>> 
>>          # Long line, probably broken by your mailer.  For clarity, I'd
>>       # write it on two lines explicitily:
>> 
>>          mysqldump -uroot -pHardAsMySql321 "$DB" |
>>         bzip2 > "${DB}_$(date +%Y-%m-%d_%k.%M).sql.bz2"
> 
> You might want to set umask restrictive so that the backup file
> created by the redirection isn't world readable.
> 
>   umask 077
> 
> I have never liked whitespace in filenames and %k may produce spaces
> in filenames.  Better IMNHO to use %H here and avoid the space.  Why
> use a dot instead of the more common colon in the time?
> 
>   mysqldump -uroot -pHardAsMySql321 "$DB" |
>     bzip2 > "${DB}_$(date +%Y-%m-%d_%H:%M).sql.bz2"
> 
>> You could also consider writing it this way:
>> 
>>   cd /
>>   rm -rf "$CURRENT_DIR"
>>   mkdir -p "$CURRENT_DIR"
>>   cd "$CURRENT_DIR" || exit 1
>> 
>> Then you don't even need to check whether it already exists.
> 
> Why bother changing directory there at all? :-)
> 
>   mysqldump -uroot -pHardAsMySql321 "$DB" |
>     bzip2 > "$CURRENT_DIR/${DB}_$(date +%Y-%m-%d_%H:%M).sql.bz2"
> 
>> Bernd Eggink wrote:
>> > You could replace the whole if-then-else clause by
>> > 
>> >     mkdir -p $CURRENT_DIR
>> >     cd $CURRENT_DIR
>> >     rm -f *
>> 
>> Another failure to check the results of "cd" before doing "rm *".  This
>> can and will lead to disasters.
> 
> Doing 'rm *' just makes me extremely nervous even when care is taken
> to ensure that it is going to work okay.  I think it is safer to avoid
> it.  Let me suggest the following:
> 
>> > CURRENT_DIR=$BACKUP_DIR/`date +%d`
>> ...
>>   cd "$CURRENT_DIR" || exit 1
>> ...
>>          mysqldump -uroot -pHardAsMySql321 "$DB" |
>>           bzip2 > "${DB}_$(date +%Y-%m-%d_%k.%M).sql.bz2"
> 
> In this case the file name is going to be SOMETHING.sql.bz2.  Instead
> of using 'rm *' it would make me much less nervous to qualify that
> file glob with 'rm -f *.sql.bz2' at least so that if this were to escape
> and be invoked elsewhere it would have limited damage potential.
> 
>   cd "$CURRENT_DIR" || exit 1
>   rm -f *.sql.bz2
> 
>> > Is there a better way to clear out last months files before making the
>> > current backups?
> 
> Personally I have the following line in my /etc/cron.d/local-mysql
> crontab.  The 'savelog' command with -c7 will save seven days of
> datestamped backups (sufficient for my case) without further code.
> That could easily be -c30 to save 30 days worth.  The 'savelog'
> command pretty much handles all of your issues with datestamping and
> cycling files very easily.
> 
>   30 3 * * *  root  umask 077 ; mysqldump
> --defaults-file=/etc/mysql/debian.cnf --all-databases | gzip >
> /var/backups/mysql.dump ; savelog -q -d -l -C -c7 /var/backups/mysql.dump
> 
> Bob
> 
> 
> 
> 

-- 
View this message in context: 
http://www.nabble.com/Help-with-script---doesn%27t-work-properly-from-cron-tp24542164p24579084.html
Sent from the Gnu - Bash mailing list archive at Nabble.com.