feat(inputs.influxdb_v2_listener): Add support for rate limiting

[LarsStegman]

Summary

As discussed in #15340 it can be beneficial for the Influx listener to rate limit any client pushing data. This change is compatible with the API spec described here: https://docs.influxdata.com/influxdb/v2/api/#operation/PostWrite

Checklist

• No AI generated code was used in this PR

Related issues

resolves #15340

[powersj]

Thanks for putting this up. Played with this locally this morning.

There is a footgun if the max_undelivered_metrics size is greater than the number of metrics sent in a batch to Telegraf the batch would never get accepted :\ That's a little different from the other plugins with tracking metrics as they pull/consume as they can.

[LarsStegman]

Good catch!
I think it would be best to send a 413 status back in that case. That kind of follows the API docs. Do you agree with this?

It should be logged as a warning(?). I'll update the code tomorrow.

[powersj]

Good catch! I think it would be best to send a 413 status back in that case. That kind of follows the API docs. Do you agree with this?

Yep! 413 sounds like the right return code.

It should be logged as a warning(?). I'll update the code tomorrow.

Hmm a warning, an error, or ignored? We usually error when we cannot parse data. It opens the question if we should do the same for the 429

[LarsStegman]

Hmm a warning, an error, or ignored? We usually error when we cannot parse data. It opens the question if we should do the same for the 429

I chose to ignore it. It is not really an error in the program, just user error. I did add a debug entry, since that might help the user pin down why batches are being rejected.

[telegraf-tiger]

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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_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz

[srebhan]

Thanks @LarsStegman!

[srebhan]

@powersj assigning it back to you as the code was changed since your accept. Feel free to merge if you are still OK with the current state. ;-)

[powersj]

Thanks for the update!