Is it possible to trigger an Event Rule ONLY when an Interface VLAN changes?

[kenancakir]

Hi everyone,
I am trying to set up an Event Rule in NetBox v4.6.0 that triggers a Webhook, but only when the untagged_vlan of an interface actually changes.

I want to automate our network configuration using Ansible. When a user changes an interface's VLAN in NetBox, it should trigger a Webhook to Ansible to automatically reconfigure the actual switch port.

Because running Ansible playbooks takes resources, I want to avoid unnecessary triggers. If someone updates other fields on the interface (like just changing the description or MTU), the Event Rule should not fire.

[Christophoclese]

Not sure if the snapshots fields delivered by the Webhooks are populated for the Event Rule conditions, but that would be the way in my opinion.

In fact, I'm not sure how to determine what properties are available in the context of an Event Rule and these appear to be different than what is sent by default by the Webhooks. For example, a delivered Webhook has branch context wrapped up in a context object in the root of the response body. In Event Rules you must directly access the active_branch property because the context object does not exist. This makes it quite difficult to reason about how to properly construct conditions for Event Rules. Maybe there's a way to do this and I'm just ignorant?

I ended up deciding to build an event handler middleware which can properly apply logic. Easy to see the full payload you're working with this way. Unfortunately, this does mean we'll be sending a number of requests that will ultimately be dropped by the handler.

[kenancakir]

Hi,
Thanks for the response.

I did some research and found an active issue about this topic: #18159. The feature could be added in v4.7.0, as seen in the issue's milestone.

However, I just tried something with Claude Code which worked perfectly. I understand that AI-generated code isn't always well-received in the community, but I don't intend to open a PR with it. I just want to share a possible solution to provide some inspiration. I'm confident the development team will know how to properly implement it for future releases.

[Christophoclese]

That does look like a reasonable implementation-- 🤞hopefully we'll be able to control this better down the road and we can achieve the efficiency we're both looking for 🚀