Encourage users to classify using `simp::classes` rather than `classes`

This log records a significant past decision that hasn't been widely circulated.

Status	Decided
Impact	LOW
Driver	@Trevor Vaughan
Approver	@Trevor Vaughan
Contributors	@Trevor Vaughan @Chris Tessmer @Liz Nemsick
Informed
Due date	Jul 1, 2019
Outcome	We should encourage users to add their own classifications using the `simp::classes` parameter instead of the (now-legacy) `classes` lookup key.

Background

https://simp-project.slack.com/archives/CA4EMBXEJ/p1562344381223000	https://app.slack.com/client/TA4GPKY1M/CA4EMBXEJ/thread/CA4EMBXEJ-1562359521.248400

https://simp-project.slack.com/archives/CA4EMBXEJ/p1562344381223000	https://app.slack.com/client/TA4GPKY1M/CA4EMBXEJ/thread/CA4EMBXEJ-1562359521.248400

Relevant data

Options considered

	Option 1:

Option 1:

Description

We should encourage users to add their own classifications using the simp::classes parameter instead of the (now-legacy) classes lookup key.

Pros and cons

The simp::classes parameter is already provided by the simp profile to support scenarios' internal classifications.

Reusing simp::classes for user classifications makes them subject to the same flow control (e.g., knockout prefixes) as the SIMP's internal classifications.

This avoids needing a lot of extra documentation to enable agentless deployments to either reuse the site.pp classification strategy, or maintain separate (and recurring) classification guidance for site.pp+classes and simp::classes.

Combining users' and the simp's internal classification data streams joins two separate concerns (impact: ¯\_(ツ)_/¯ )

Estimated cost

LOW

Action items

Outcome

We should encourage users to add their own classifications using the simp::classes parameter instead of the (now-legacy) classes lookup key.