Cron + rsnapshot interaction fails to parse arguments

M

mix_room

I have a backup script in order to backup a MySQL-database to my backup server.

I run rsnapshot from cron at defined intervals. This works correctly.

Rsnapshot calls a script (backup_script parameter) which calls mysql_dump.

The script works perfectly from the command line. Rsnapshot does not return any errors when i run it from CLI either (rsnapshot hourly)

When rsnapshot is run from cron I get an error message delivered to the email which states
Code: 
--host host.domain.tld    not found

The line in the backup script is as follows

Code: 
$mysqldump --host $host.$domain ...additional parameters > $GZIP

I used to have
Code: 
--host "$host.$domain"
, but that returned errors aswell.

My cron enviroment sets the shell to /bin/sh.

As the task runs quite frequently my inbox is filling up. I would greatly appreciate any help. Should it be necessary I can post my scripts once I have access to the machine in question.
 
It is not consistent with the error message, but try one of these:

1. setting cron's PATH to include the directory to the mysqldump binary
2. using full pathnames in any script executed from cron
 
Oh, wait a minute ...

Code: 
o  --host=host_name, -h host_name

It's one or the other ;)
 
DutchDaemon said:
1. setting cron's PATH to include the directory to the mysqldump binary
Click to expand...

2. using full pathnames in any script executed from cron
Click to expand...

I already did that. I use full pathnames both in cron and in the backup script

Oh, wait a minute ...

Code: 
o  --host=host_name, -h host_name

It's one or the other
Click to expand...

I will check that, but I think that I have already used --host=host_name. I was retyping the script from memory when I posted my original question.
 
Ok, if the problem persists, try running the script from cron with '/bin/sh -xv' in front of it to capture the full output. See how all of the variables expand as seen from cron.
 
As suggested I ran the backup script from rsnapshort using '/bin/sh -xv'. Output is attached below.
Code: 
#!/bin/sh
# Use mysqldump to dump a database to a compressed file.
# In order to restore the database run the following command
# gunzip < BACKUP.GZ | mysql --user --host -p DATABASE

MUSER="SECRETUSER"
+ MUSER=SECRETUSER
MPASS="SECRETPASSWORD"
+ MPASS=SECRETPASSWORD
MHOST="sqlhost"
+ MHOST=sqlhost
MDOMAIN="domain.tld"
+ MDOMAIN=domain.tld

DATABASE="db1 db2"
+ DATABASE=db1 db2
DATE=`date -j "+%Y%m%d"`
+ date -j +%Y%m%d
+ DATE=20090813
OUTPUT="${MHOST}_${DATE}.mysql.gz"
+ OUTPUT=sqlhost_20090813.mysql.gz

MYSQL=`which mysql`
+ which mysql
+ MYSQL=
MYSQL_DUMP=`which mysqldump`
+ which mysqldump
+ MYSQL_DUMP=
GZIP=`which gzip`
+ which gzip
+ GZIP=/usr/bin/gzip

$MYSQL_DUMP --host=$MHOST.$MDOMAIN --user=$MUSER --password=$MPASS --databases $DATABASE | $GZIP -9 > $OUTPUT
+ + --host=sqlhost.domain.tld /usr/bin/gzip --user=SECRETUSER -9 --password=SECRETPASSWORD
 --databases db1 db2
--host=sqlhost.domain.tld: not found
 
Was this run from cron?

Two things jump to the eye:
Code: 
MYSQL=`which mysql`
+ which mysql
+ [B]MYSQL=[/B]
MYSQL_DUMP=`which mysqldump`
+ which mysqldump
+ [B]MYSQL_DUMP=[/B]

Both are empty, which means the actual command line becomes:
Code: 
[empty] --host=$MHOST.$MDOMAIN

And [cmd=]--host[/cmd] is not a valid command.

Find out why [cmd=]which mysql[/cmd] and [cmd=]which mysqldump[/cmd] fail (I think you may have to add /usr/local/bin to cron's PATH setting(*)), or just put the full path in the variables yourself.

(*) put PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin as the first line in the crontab
 
DutchDaemon said:
Was this run from cron?
Click to expand...
Yes. I ran rsnapshot from cron. rsnapshot then ran the backupscript.

Both are empty, which means the actual command line becomes:
Code: 
[empty] --host=$MHOST.$MDOMAIN

And [cmd=]--host[/cmd] is not a valid command.
Click to expand...
Which should be quite obvious. Thank you for pointing that out.


Find out why [cmd=]which mysql[/cmd] and [cmd=]which mysqldump[/cmd] fail (I think you may have to add /usr/local/bin to cron's PATH setting(*)), or just put the full path in the variables yourself.
Click to expand...

Will do.

I'll let you know how this works out once it has been implemented.
 
I made some changes to my script:

1) Output $PATH
Code: 
echo $PATH
+ echo /usr/bin:/bin
/usr/bin:/bin
Seems as though $PATH is not complete, that explains why mysqldump was not found.
I also added the direct path:
Code: 
MYSQL="/usr/local/bin/mysql"
+ MYSQL=/usr/local/bin/mysql
MYSQL_DUMP="/usr/local/bin/mysqldump"
+ MYSQL_DUMP=/usr/local/bin/mysqldump
GZIP=`which gzip`
+ which gzip
+ GZIP=/usr/bin/gzip

It seem's as though it has worked.
Code: 
$MYSQL_DUMP --host=$MHOST.$MDOMAIN --user=$MUSER --password=$MPASS --databases $DATABASE | $GZIP -9 > $OUTPUT
+ + /usr/local/bin/mysqldump/usr/bin/gzip --host=sqlhost.domain.tld -9 --user=SECRETUSER
 --password=SECRETWORD --databases db1 db2

One question that remains: the output of the last line ($mysqldump ARGS | $gzip ARGS) seems odd. Is this a problem, or just due to the output formatting of /bin/sh?

Greatly appreciate your help.
 
Yes, that looks like an artefact of the shell trying to put verbose output on a single line. Looks like a small race condition. It sometimes happens when shutting down the OS as well, when the OS starts printing a lot of information in a very short time, leading to garbled output. It's not a problem.
 
As for the script itself: I think adding that PATH to the top of the crontab is the cleaner solution. By default, cron doesn't know about the executables in /usr/local, whereas the 'user shell' does. So just nudge cron to use the extended path.
 
DutchDaemon said:
As for the script itself: I think adding that PATH to the top of the crontab is the cleaner solution. By default, cron doesn't know about the executables in /usr/local, whereas the 'user shell' does. So just nudge cron to use the extended path.
Click to expand...

I agree that adding /usr/local/ in cron's PATH is the cleaner solution. However it was not the quick-n-dirty solution.
 
It works now.

I added the entire $PATH from my normal shell to cron. That seems to have solved the problem. Now my mailbox doesn't fill up every day.

Thanks again for the help.
 
You must log in or register to reply here.
Back
Top