This project is inspired by cronic and includes some extra useful functions such as sending email error report through SMTP and store logs of crontab scripts.
Crontab has the ability to send mail notification when any output was generated executing your script, as we know. It will send a bunch of emails to you every day if you have a lof of scripts. What if we only want to get the mail when something goes wrong?
As a result, You may config your crontab like this:
# Redirect all standard output to /dev/null so we will get an email # only if this script has some standard error output. * * * * * some_work > /dev/null # Or this to ignore all output for lazy people, but you will never # be notified if your script fails. * * * * * some_work > /dev/null 2>&1
Using pycronic make things simplier:
cronic="/usr/local/bin/cronic" * * * * * &cronic some_work
All you need is to prepend cronic to your script execution command. cronic command will check the return code and the error output for you, if something wents wrong, you will get an email notification through crontab's default mailing system or your customized STMP server.
MAIL TITLE: [Cronic@server1] Error occoured when running "backup" MAIL CONTENT: Cronic Error Report =================== [2013-11-12 16:07:24.228788] Cronic detected failure or error output for the command: backup RESULT CODE: 2 ERROR OUTPUT: ~~~~~~~~~~~~~ Can not connect to database! STANDARD OUTPUT: ~~~~~~~~~~~~~~~~ Starting backup...
And cronic will store all your scripts output to a directory (/tmp/pycronic by default).
# Install from pypi sudo pip install pycronic # Latest version from git sudo pip install https://github.com/piglei/pycronic/archive/master.zip # Or install from github sudo pip install -e git+https://github.com/piglei/pycronic/#egg=pycronic
Note: pycronic is now python3 compatible, you can install using
pip3 install ...
After the installation, run "cronic" in your command line to verify:
$ cronic Usage: cronic YOUR_COMMAND $ cronic ls Config file "/etc/pycronic.conf" does not exist! Run "cronic init" to create a default one."
Then run "sudo cronic init" to create a default config file under /etc, the default config file should look like this:
# Log path for pycronic, pycronic will store all logs to this directory log_path = /tmp/pycronic # Send an error email or not, default to not send send_alert_email = True # Email Title mail_title = [Cronic@%(host)s] Error occoured when running "%(command)s" # Email receivers # receivers = email@example.com # Email smtp server config [email_config_smtp] # username = username # host = smtp.sample.com # password = password # from = Cronic <firstname.lastname@example.org> # port = 587
How to use
cronic will be silent if no error occured when running a script:
piglei@macbook-pro:etc$ cronic ls piglei@macbook-pro:etc$ cat /tmp/pycronic/ls.log [The script result will be stored in the log file]
But if an error has occured (cronic will check the standard error output), it will print an error message like this:
$ cronic ls asdf Cronic Error Report =================== [2013-11-12 15:49:03.349575] Cronic detected failure or error output for the command: ls asdf RESULT CODE: 1 ERROR OUTPUT: ~~~~~~~~~~~~~ ls: asdf: No such file or directory STANDARD OUTPUT: ~~~~~~~~~~~~~~~~ None
If you have configured your crontab an email will send to your email address.
You can also modify config to send mail through SMTP instead of using crontab which is highly more recommended.
Now config your crontab, using pycronic to wrap your scripts:
$ crontab -e # If you have not config your pycronic.conf's smtp config, you can still # use crontab to send error emails. MAILTO="email@example.com" cronic="/usr/local/bin/cronic" */5 * * * * $cronic YOUR SCRIPT