Component

API Server / GraphQL

Infrahub version

1.9.3

Current Behavior

When an IpamIPPrefix reports non-zero utilization on main, creating a new branch from main causes the same prefix to report utilization: 0 on the branch — even though no data has been modified.

The effect shows up on every prefix that had non-zero utilization on main: a fully populated /32 sub-prefix (with its host IpamIPAddress assigned) and its /24 parent both flip to 0 on the branch. The exact percentages aren't the point — utilization values are not preserved on branch creation.

Expected Behavior

A freshly created branch should report the same utilization as main until data on the branch is modified.

Steps to Reproduce

1. Load the models/base/ipam.yml schema, which provides IpamIPPrefix and IpamIPAddress (inheriting from BuiltinIPPrefix / BuiltinIPAddress):

   infrahubctl schema load models/base/ipam.yml

2. Load the following objects on main:

   ---
   apiVersion: infrahub.app/v1
   kind: Object
   spec:
     kind: IpamIPPrefix
     data:
       - prefix: 10.100.0.0/24
         description: "Parent /24 — container for /32 sub-prefixes"
         member_type: prefix
   
   ---
   apiVersion: infrahub.app/v1
   kind: Object
   spec:
     kind: IpamIPPrefix
     data:
       - prefix: 10.100.0.1/32
         member_type: address
       - prefix: 10.100.0.2/32
         member_type: address
       - prefix: 10.100.0.3/32
         member_type: address
       - prefix: 10.100.0.4/32
         member_type: address
   
   ---
   apiVersion: infrahub.app/v1
   kind: Object
   spec:
     kind: IpamIPAddress
     data:
       - address: 10.100.0.1/32
       - address: 10.100.0.2/32
       - address: 10.100.0.3/32
       - address: 10.100.0.4/32

   infrahubctl object load ipam_utilization_bug_repro.yml

3. Open the IPAM view at http://localhost:8000/ipam on main — the /24 and each /32 sub-prefix show non-zero utilization.

4. Create a new branch:

   infrahubctl branch create test-1

5. In the same IPAM view, switch the branch selector to test-1. Every prefix that reported non-zero utilization on main now reports 0 on test-1, while main is unchanged.

Additional Information

• IPPrefix.utilization, IPPrefix.ip_addresses, and IPAddress.ip_prefix are all declared read_only=True with allow_override=NONE in backend/infrahub/core/schema/definitions/core/ipam.py (lines 116-122, 166-175, 219-228). The hierarchical prefix→address association is computed, not stored.
• The sub-prefix and address objects themselves remain visible on the branch — only the utilization value is affected.