Nautobot Cable Utilities

Nautobot app for what cable management in Nautobot 3.2 still lacks:

• Cable inventory: the cables in storage, as ordinary cables without ends and with the status In Stock.
• Commission / Undo Commission: hand a stock cable to a Planned cable, standard or breakout, or take it back.
• Device Commission: commission all Planned cables of a device in one loop, with QR code scanning.
• Auto-Link: propose and create Planned cables between ports through patch panels in different racks.

Nautobot 3.2 changed how cables attach to ports, so 3.0 and 3.1 are not supported. PostgreSQL is required. The router reads Nautobot's cable tables with raw SQL, which is why the supported range stops below 4.0. See CHANGELOG.md for what changed.

Installation

Install into the same environment as Nautobot:

pip install nautobot-cable-utils

Enable the app in nautobot_config.py (no PLUGINS_CONFIG entry needed):

PLUGINS = ["nautobot_cable_utils"]

Then run migrations and restart Nautobot:

nautobot-server post_upgrade

post_upgrade creates the cable status In Stock, the custom fields Cable number, Plug and Procurement identifier, and the relationships Cable owner, Cable supplier and Cable storage rack. The choices for Plug are yours to add under Extensibility → Custom Fields → Plug.

Permissions

• dcim.view_cable for the menu entry and the stock list.
• dcim.add_cable to add or import stock cables and to use Auto-Link.
• dcim.change_cable and dcim.delete_cable for Commission and Device Commission (the stock cable is consumed).
• dcim.change_cable and dcim.add_cable for Undo Commission (the stock cable is recreated).

Commission, Undo Commission and Device Commission respect constraints on these permissions: they only reach cables the user may change, and stock cables the user may delete.

Upgrading from 1.x

Upgrade Nautobot to 3.2 or newer together with the app.

• Stock cables replace the inventory. Migration 0013 turns every inventory item into a stock cable and 0014 drops the old tables. Free items become cables with status In Stock, items in use keep their cable and only get the number and the rest. name becomes the custom field Cable number, plug the custom field Plug (its choices are the old plugs), procurement_ident the custom field Procurement identifier, and owner, supplier and storage_rack the relationships Cable owner, Cable supplier and Cable storage rack. The REST endpoints cable-inventory-item and cable-plug are gone; use /api/dcim/cables/?status=In%20Stock. Rehearse the migration on a copy of your database.

• Lengths without a unit (the old form allowed them) become meters, because a cable needs a unit for its length.

• Commission works on the cable you already have. The planned cable keeps its id and ends and receives the data of the stock cable; the stock cable is deleted. Undo Commission turns it back.

• Measurement logs are removed. Migration 0012 drops the table nautobot_cable_utils_measurementlog, and the rows cannot be restored afterwards. Export them before running post_upgrade, for example in psql:

  \copy nautobot_cable_utils_measurementlog TO 'measurement_logs.csv' CSV HEADER
  

• Reconnect is gone. The button on a cable now opens Nautobot's own Edit Cable page, which changes the terminations of the same cable.

• Permissions: commissioning now checks dcim.change_cable and dcim.delete_cable. 1.x checked dcim.edit_cable, which Nautobot does not define, so grant change and delete on Cable to everyone who commissions.

• The menu entry moved from Apps to Devices → Cable Utilities → Cable Inventory, right after Nautobot's own Connections group with Cables.

Usage

Screenshots show the Nautobot 2 UI; the pages look different in Nautobot 3 but work the same.

Cable inventory

Open Devices → Cable Utilities → Cable Inventory. It lists every cable, in stock, planned or connected, with the columns number, label, status, A and B ends, cable type, plug, owner, supplier, storage rack and procurement identifier. Stock cables, Planned cables and Connected cables open the same list narrowed by status: a Planned cable is waiting for a stock cable, a Connected cable keeps its number after it was commissioned. All of Nautobot's cable filters, exports and bulk actions work on it, and the plain list stays under Devices → Connections → Cables.

A stock cable is a normal cable, so everything else about it is edited on its cable page: type, color, length and, for a fan-out cable, the cable type (for example 1x4 Breakout). The cable number is unique across all cables.

• Add stock cables takes a number pattern such as T-[1-20] and the properties all of them share.
• Import stock cables takes CSV with the columns cable_number, label, type, cable_type, plug, color, length, length_unit, owner, supplier, storage_rack and procurement_ident. Only cable_number is required (name, the 1.x column name, also works). cable_type, owner, supplier and storage_rack are given by name or id; use the id when a name, such as a rack name, is not unique. length is a whole number up to 32767. The import is all or nothing.

Commission and Undo Commission

On the page of a Planned cable with ends, Commission asks for a cable number, typed or scanned with the camera (browsers allow camera access only over HTTPS). The page lists every end of the cable: A1 and B1 for a standard cable, A1, B1 to B4 for a 1x4 Breakout. The cable becomes Connected and takes over the type, label (the number if there is none), color, length, number, plug, procurement identifier, owner, supplier and storage rack of the stock cable. The stock cable is deleted, and with it its tags, notes and other custom fields: only the properties listed here are carried over.

Both cables need the same cable type. Change the cable type of the planned cable first if they differ.

Undo Commission appears on a commissioned cable. After confirmation, the cable is Planned again with its properties cleared, its ends untouched, and the stock cable exists again with all its data.

Device Commission

A device with Planned cables shows a Device Commission button.

It walks through the Planned cables one by one, each cable once, however many of its ends are on the device. The page shows how many are left, every end of the cable and the cable number field.

• Create commissions the cable with the entered number and shows the next one.
• Skip leaves it Planned and shows the next one.
• Cancel stops and returns to the device.
• Scan reads the cable number from a QR code.

The loop is stored in the session. If you leave without pressing Cancel, it continues at the same cable when you come back, until the session expires or you start another device. Skipped cables only show up again after Cancel and a fresh start.

Auto-Link

On an interface or front port without a cable, Auto-Link offers an interface or a front port as destination.

Choose the destination and the media type. The app shows the proposed cable trace and the Planned cables it would create.

The router builds a graph with all racks as vertices and the cables between rear ports of rack-mounted patch panels as edges. It finds a path from the source rack to the destination rack and lists the cables still needed. Create adds them with Planned status, all or none.

Allow Next Rack Patches lets the path hop to a neighboring rack in the same location. Neighbors are decided by the SQL function is_neighbor() from migration 0009, which only knows GWDG's rack names (1519-…, V1519.…, V2356.…). With other rack names the option has no effect; to add a naming scheme, replace that function. Breakout cables are not routed.

Development

Tests need a Nautobot 3.2+ environment with PostgreSQL:

nautobot-server test nautobot_cable_utils

CI runs flake8 . on Python 3.11 to 3.14.