[Agent 6] Put check config in <check>.d directory

[KSerrania]

What does this PR do?

If Agent 6 is installed, puts the check config files in their respective <check>.d folder.

Motivation

Check config files were put in the conf.d folder directly, which is the standard for Agent 5, but not Agent 6.

[hegyre]

Hello @KSerrania ,
Since 3.0 contains breaking changes and is installing agent v7 by default.
And since this PR concerns Agent v6+, is it possible to create a release 2.1.1 including this fix only ?

Also, if checks are already present in {{ datadog_install_settings.confd_path }}/ instead of {{ datadog_install_settings.confd_path }}/{{ check_name }}.d/ (because we are using version 2.0 of this formula), when we will migrate to v3.0 or v2.1.1, the checks on old locations will be moved / removed, or they will be duplicated ?

[KSerrania]

Hi @hegyre,

As you guessed, for now when going from 2.1 to 3.0, the checks will be duplicated. This is a bug, as the Agent will pick up both config files, resulting in multiple instances of the check to be run. I'll do a follow-up PR for this and a bugfix release for 3.x.

I'll then create a 2.2 release with both this PR + the fix for the aforementioned issue.

[hegyre]

Hello @KSerrania,
Any news on a possible 2.2 version ?

Thanks in advance.

[KSerrania]

Hey @hegyre,

Thanks for reminding me of that! I'll draft a 2.2 release with this and #47 tomorrow.

[hegyre]

Hey @KSerrania ,
Thanks for the info, that sounds great!

[KSerrania]

Here's the release PR: #55. I'll do some sanity checks on the 2.x branch next week (it's been a while since I last touched 2.x code, so I want to make sure the backports work). I'm targeting a release date sometime between mid and end of next week.