Cron job execute backup.bash

Question

Dear all,

I wish to let cron executes delete_snapshot.bash, but when I try to create cron as below:
*/1 * * * * /var/www/mango_gis/delete_snapshot.bash >/dev/null
It didn't execute my script at all, because when I didn't see it delete the snapshot in the amazon cloud, and my script is already tested with bash, it work fine.

Here is my script as below:

#!/bin/bash

get()
{
    local pos=$1
    shift
    eval 'echo ${'$pos'}';
}

length(){ echo $#; }

find_snapshots()
{
    echo $(ec2-describe-snapshots | xargs -n1 basename);
}

snapshots=$(find_snapshots)
len=$(length $snapshots)
row_count=$(($len/6))

if(($row_count > 6)); then
    delete_count=$(($row_count-6))
    for (( i=1; i<=$delete_count; i++ )); do
            ec2-delete-snapshot $(echo $(get $((2+$((6*$(($i-1)))))) $snapshots)) > /dev/null
    done
fi

In above, I have found the problem is that I call one command of EC2 command.
I have tested to create one cron job to call this command is ec2-describe-snapshots,
but it doesn't work.

Please advise...

Leakhina

Answer 1

you should add the program with which you want to process this file; something like:

*/1 * * * * /bin/bash  /var/www/mango_gis/delete_snapshot.bash > /dev/null

using the full path is important, because you do not have the environment variables loaded when cron starts the process

Answer 2

thanks for your help so far. Now I can catch it.

the problem is that cron not load the env variable so we just need to specify what we use to env variable while cron executing. here is my test code for ec2 command as below:

export EC2_PRIVATE_KEY=/root/keys/pk-Q4NR5FGDTSWWK65EDSIDCBTEQWJ6G24V.pem export EC2_CERT=/root/keys/cert-Q4NR5FGDTSWWK65EDSIDCBTEQWJ6G24V.pem export JAVA_HOME=/usr/lib/jvm/java-6-sun/ export EC2_HOME_BIN=/usr/bin

echo "start ec2-describe-snapshots" >> /var/log/ec2-delete-snapshot.log $EC2_HOME_BIN/ec2-describe-snapshots >> /var/log/ec2-delete-snapshot.log echo "end it" >> /var/log/ec2-delete-snapshot.log