netbox-render

A NetBox plugin I wrote to fix a visibility gap in rack elevations: devices with device bays render as a single opaque block, hiding what's actually installed. This plugin subdivides that block into labeled, color-coded, clickable sections — one per bay.

What it does

Out of the box, NetBox shows a device-bay device as one rectangle with an occupancy count like "3/4". To see what's installed, you have to click into the parent and check the Device Bays tab.

I patched RackElevationSVG._draw_device so each bay gets its own section showing:

• Bay index (1, 2, 3, ...) sorted by bay name
• Child device name, or "(empty)"
• Role color on the front face (rear renders grey, matching stock behavior)
• Clickable link to the child device page

Devices without bays are untouched.

Before and after

Without plugin	With plugin
Single opaque block	Subdivided with bay labels and role colors

Bay ordering

Bays sort alphabetically by name — there's no numeric position field in NetBox's device bay model. Name them "Slot 01", "Slot 02", etc. for predictable ordering.

Compatibility

Startup checks verify the patched method signature hasn't changed. If it has, the plugin raises a RuntimeError instead of loading.

Installation

pip install netbox-render

Add to configuration.py:

PLUGINS = ['netbox_render']

Restart NetBox:

sudo systemctl restart netbox netbox-rq

For development: pip install -e .

Configuration

One option in PLUGINS_CONFIG:

PLUGINS_CONFIG = {
    'netbox_render': {
        'enable_images': True,  # default: False
    },
}

When enabled, bay sections show the child device type's front/rear image with a text label overlay. Requires restart.

Shelf device guide

See Shelf-devices Guide for a walkthrough on modeling rack shelves using device bays and how this plugin renders them.

Known limitations

• Bay ordering is name-based, not positional — no way around this without modifying NetBox's data model
• Images off by default
• Rear face always renders grey (matches stock NetBox)
• Both faces show the same bay breakdown
• No migrations, no DB changes — rendering only
• Monkeypatch approach: I patch an internal method, so test after every NetBox upgrade

Support

• Bugs / feature requests: GitHub Issues
• Questions: GitHub Discussions
• Security: Security Advisories (not public issues)

License

Apache-2.0