Add a generic Role model

[dgarros]

Environment

• Python version: 3.77
• Nautobot version: 1.1.4

Proposed Functionality

Add a generic Role model, similar to Status to avoid creating multiple models that are describing pretty much the same things.
Currently in Core, we are leveraging roles in multiple places :

• Dynamic based on database model : ipam:Role, dcim:DeviceRole, dcim: RackRole
• Static : ipam ? IPAddressRoleChoices

I wouldn't be surprised if we are using roles in more places

Use Case

• Improve the user experience by allowing users to manage roles in a single place.
• Reduce the effort to add role to more models, as part of core or as part of a plugin
• Allow static role to become dynamic.

Database Changes

Yes
At a minimum we need to add a new role model, most likely as part of Extras that will be very similar to Status.
At some point, it would be good to migrate all existing roles to this new model but it would most likely be a breaking change

External Dependencies

No

[jathanism]

Yeah we talked about this back pre-1.0 for things like "profiles" e.g. "interface profiles" but just using roles generically. I'm a fan.

[glennmatthews]

This would probably be difficult to implement in a non-breaking / backwards compatible way. Need to consider impact to the REST API, plugins potentially consuming these data models, etc.

Setting that aside, it would be worth looking at whether we even need separate data models for "status" and "role" or whether these are just two different groupings/uses of the same generic model type behind the scenes? (In theory even "tag" could be subsumed into this as well...)

Currently we're leaning towards targeting this as a 2.x feature - not to rule out implementing it before then if these sorts of concerns can be addressed in a backwards-compatible way.

[dgarros]

Understood, retrofitting the existing models wouldn't be backward compatible

It might be possible to introduce the new Role model first, to allow plugins to leverage it and retrofit the existing models later as part of a major release.

[jvanderaa]

This is probably something that could be implemented across the boards, including supplanting Location Type. @bryanculver

[Kircheneer]

I can also see use in this as a feature for plugin developers, if all I need is an extendable list of possible types otherwise I would have to define a custom model with lots of extra overhead, if we had this and it was extendable to plugin models that could save me as a plugin developer some time. One example from a currently open-sourced plugin would be nautobot_bgp_models.models.PeeringRole, this is a very simple model without custom logic that just provides an extendable role field.

[glennmatthews]

Another candidate model for rolling into a generic Role would be the CircuitType model.

[glennmatthews]

Implemented for 2.0 by #2822.