🦄 Investigate what detects a change in Ansible so we can update the Node in the inventory in OpenNMS Horizon.

[indigo423]

When we create a node in OpenNMS Horizon, we might want to update the node in the requisition based on changes on the node itself reflected via Ansible facts. OS changed, Memory increased, etc. How can we detect a change and run a node provisioning on these changes.

[mfuhrmann]

Right now I see two approaches here.

1. Diff node configurations
   We could GET the existing node definition from the node API and compare the XML code with the one the playbook generates. If there is a mismatch, we probably can use a PUT to overwrite the existing configuration. I think the API provides the XML output as a one-liner. The playbook would need to to it the same for a diff, I think.

2. Delete existing nodes first
   When the foreign_id is the same, a node can be deleted without deleting the collected performance data. It could be re-provisioned then and the graphs will still work. The con here is, the existing events will be deleted because the "new" node will get the different database id.