symfonycorp / croncape

Croncape wraps commands run as cron jobs to send emails only when an error or a timeout has occurred.

Croncape

Croncape wraps commands run as cron jobs to send emails only when an error or a timeout has occurred.

Out of the box, crontab can send an email when a job generates output. But a command is not necessarily unsuccessful "just" because it used the standard or error output. Checking the exit code would be better, but that's not how crontab was standardized.

Croncape takes a different approach by wrapping your commands to only send an email when the command returns a non-zero exit code.

Croncape plays well with crontab as it never outputs anything except when an issue occurs in Croncape itself (like a misconfiguration for instance), in which case crontab would send you an email.

Installation

Download the binaries or go install github.com/symfonycorp/croncape@latest.

Usage

When adding a command in crontab, prefix it with croncape:

[email protected]
0 6 * * * croncape ls -lsa

That's it!

Note that the MAILTO environment variable can also be defined globally in /etc/crontab; it supports multiple recipients by separating them with a comma.

You can also customize the email sender by setting the MAILFROM environment variable.

If you need to use "special" shell characters in your command (like ; or |), don't forget to quote it and wrap the command in a shell:

0 6 * * * croncape bash -c "ls -lsa | true"

Besides sending emails, croncape can also kill the run command after a given timeout, via the -t flag (disabled by default):

0 6 * * * croncape -t 2h ls -lsa

If you want to send emails even when commands are successful, use the -v flag (useful for testing).

Use the -h flag to display the full help message.

Croncape is very similar to cronwrap, with some differences:

• No dependencies (cronwrap is written in Python);

• Kills a command on a timeout (cronwrap just reports that the command took more time to execute);

• Tries to use sendmail or mail depending on availability (cronwrap only works with sendmail);

• Reads the email from the standard crontab MAILTO environment variable instead of a -e flag.

For a simpler alternative, have a look at cronic.

croncape's Issues

Write stdout to a log file

Hi,

It's not an issue, but I'm wondering if it's possible to write the standard output to a file without the -v parameter. I'd like to keep the email sent only when there is an error and log stdout to a file on each cron execution.

Really nice job by the way. 👍

Add support for cronwrap -t flag

see https://pypi.python.org/pypi/cronwrap/1.4

Installation is not working

Hello @fabpot,

When i'm trying to install Croncape following your documentation (https://github.com/symfonycorp/croncape#installation), like this :

go get github.com/symfonycorp/croncape

I got this error :

go: go.mod file not found in current directory or any parent directory.
	'go get' is no longer supported outside a module.
	To build and install a command, use 'go install' with a version,
	like 'go install example.com/cmd@latest'
	For more information, see https://golang.org/doc/go-get-install-deprecation
	or run 'go help get' or 'go help install'.

When i follow recommendations found here https://go.dev/doc/go-get-install-deprecation, like this :

go install github.com/symfonycorp/[email protected]

Everything works as expected,

I guess the command is not the same, depending on the version of Go used localy. I'm using go version go1.18.1 linux/amd64

Thank you,

Jérôme