crontab and crontab-u parsers fail if the only entry in the file has a special schedule

[rrechtin]

Apologies if anything is off, this is my first time submitting an issue on github.

I was attempting to use the ansible community.general.jc filter to parse crontab files, and ran into an issue. I have traced it to the crontab and crontab-u parsers. If the file contains only entries with "special" schedules (such as @hourly, @reboot, etc), the parser fails. This is due to the fact that when it reaches the part to append to the raw_output, because it was not initialized, it errors out.

I have attached two files with the example output (you get essentially the same output with crontab-u):

cat ~/test_jc_without_normal.txt | jc --crontab
jc:  Error - crontab parser could not parse the input data.
             If this is the correct parser, try setting the locale to C (LC_ALL=C).
             For details use the -d or -dd option. Use "jc -h --crontab" for help.

cat ~/test_jc_with_normal.txt | jc --crontab
{"variables":[],"schedule":[{"minute":["*"],"hour":["*"],"day_of_month":["*"],"month":["*"],"day_of_week":["*"],"command":"root /bin/sh do_the_other_thing"},{"occurrence":"daily","command":"root /bin/sh do_the_thing"}]}

test_jc_with_normal.txt
test_jc_without_normal.txt

[kellyjonbrazil]

Thank you for reporting this issue! It looks like this could be a quick fix. Thanks for the samples!

[kellyjonbrazil]

I have a fix for this in the dev branch. You can test by copying the files to your plugin directory:
https://github.com/kellyjonbrazil/jc/blob/dev/jc/parsers/crontab.py
https://github.com/kellyjonbrazil/jc/blob/dev/jc/parsers/crontab_u.py

• Linux/unix: $HOME/.local/share/jc/jcparsers
• macOS: $HOME/Library/Application Support/jc/jcparsers
• Windows: $LOCALAPPDATA\jc\jc\jcparsers

Let me know if you run into any other issues!

[rrechtin]

(Short version: fix works)

This may just be me being dense, but maybe you can help me out.

We're using a container to run ansible, and utilizing JC via ansible in the docker container. I have not been able to utilize the $HOME/.local/share/jc/jcparsers directory (/root/.local/share/jc/jcparsers) for parsers while using ansible. I can shell into the container and manually run cat "file" | jc --"custom-parser" and successfully parse, but ansible throws an error saying the parser isn't available.

If I rebuild the container to put the file in the jc distribution location under /usr/local, the fix works even through ansible.

[kellyjonbrazil]

This is a limitation with the Ansible plugin today. It doesn’t find plug-in parsers like the CLI - it only knows about built-in parsers.

I can update the Ansible plugin to use the newer API so it can find parsers in the plugin directory. In the mean-time you’d have to manually change out the file under jc/parsers wherever it is installed on your system/container until I get the fix in the next release.

It’s probably about time I update the Ansible plugin.

[rrechtin]

No problem, that's easy to do for the container.

Thank you very much for the quick response and fix!

[kellyjonbrazil]

FYI, I have submitted a PR to Ansible Community General to update the jc Filter Plugin to allow parser plugins:

ansible-collections/community.general#6043

[kellyjonbrazil]

Added in v1.23.0