fix: Fix panic in parsers due to missing Log

[srebhan]

• Updated associated README.md.
• Wrote appropriate unit tests.
• Pull request title or commits are in conventional commit format

resolves #10285
resolves #10286

Plugins using the SetParserFunc do not initialize the parsers' Log field properly (nor do they call Init()). This PR fixes the resulting panic by doing the initialization properly.

A quick search shows that file, tail and directory_monitor seem to be hit by this bug.

[telegraf-tiger]

Thanks so much for the pull request!
🤝 ✒️ Just a reminder that the CLA has not yet been signed, and we'll need it before merging. Please sign the CLA when you get a chance, then post a comment here saying !signed-cla

[srebhan]

!signed-cla

[telegraf-tiger]

Thanks so much for the pull request!
🤝 ✒️ Just a reminder that the CLA has not yet been signed, and we'll need it before merging. Please sign the CLA when you get a chance, then post a comment here saying !signed-cla

[telegraf-tiger]

👍 This pull request doesn't change the Telegraf binary size

📦 Looks like new artifacts were built from this PR.

Expand this list to get them here ! 🐯

Artifact URLs

DEB	RPM	TAR GZ	ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_i386.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	s390x.rpm	linux_amd64.tar.gz
mipsel.deb	x86_64.rpm	linux_arm64.tar.gz
ppc64el.deb		linux_armel.tar.gz
s390x.deb		linux_armhf.tar.gz
		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_s390x.tar.gz
		static_linux_amd64.tar.gz

[srebhan]

!signed-cla

[telegraf-tiger]

Thanks so much for the pull request!
🤝 ✒️ Just a reminder that the CLA has not yet been signed, and we'll need it before merging. Please sign the CLA when you get a chance, then post a comment here saying !signed-cla

[tarjei]

I tested this PR and it fixed #10285 for me.

[hluaces]

In #10286 I provided a Dockerfile that reproduced the issue.

With the artifact provided on this PR for RPM-based x86_64 systems the issue seems to be solved.

[MyaLongmire]

Thank you for the quick fix!

[tarjei]

@srebhan when do you think this will be in a new release?

[srebhan]

@tarjei there will be a 1.21.1 release, not exactly sure when...

[srebhan]

@tarjei oh it's already on the Download page... :-)