Enable filtering devices by assigned rack face

[ebusto]

Environment

• Python version: 3.5.4
• NetBox version: 2.4.3

Proposed Functionality

Add the ability to search for devices based on rack position and face.

Use Case

It is handy to be able to search for devices in a specific part of a rack, which the combination of position and face should accomplish. I believe this is a trivial change to netbox/dcim/filters.py.

Database Changes

None.

External Dependencies

None.

[jeremystretch]

FYI position is already an available filter.

[jeremystretch]

We may have painted ourselves into a corner with this one. The face is stored as a nullable integer value in the database, with 0 meaning front and 1 meaning rear (and null meaning neither). However, we're using 0 as a special value to represent null for filters, so querying ?face=0 will return only devices with no face assignment.

We have a few options:

1. Change the face field to use different values (e.g. "front" and "rear") instead of 0 and 1. This requires a database migration.
2. Use different values for the filter. I don't like this because it's inconsistent. For example, querying ?face=front will return a device which has face=0.
3. Change the value used to represent null. While an argument can be made for this option, it's likely too disruptive to be justified.

[jeremystretch]

Marking this as blocked by #2632

[tb-killa]

Hi I would ask if there is something new?
#2632 is closed and I like your idea of:

Change the face field to use different values (e.g. "front" and "rear") instead of 0 and 1.

[candlerb]

@tb-killa: #2632 was closed because it was implemented in 2.5.0.

This opens the route to implementing a filter for face=0, face=1 and face=null, but I don't think that's been implemented yet (hence this ticket remains open)