[CheckMK] Connect secondary CheckMK server to main server

[acozine]

What maintenance needs to be done?

We have two special CheckMK servers that live on the Out Of Band network and monitors things like temperature sensors that are not accessible from the main network. For visibility, we want status updates from that server to show up on the main server.

Level of urgency

• High
• Moderate
• Low

Why is this maintenance needed?

As a member of the IT team, I want the ability to see all monitoring data in one place.

Acceptance criteria

• lib-vm-monit2 and its sibling server can send monitoring data to pulcheck-staging.princeton.edu
• pulcheck-staging.princeton.edu can accept monitoring data
• all monitoring data is visible in the UI at pulcheck-staging.princeton.edu

Implementation notes, if any

Documentation: https://docs.checkmk.com/latest/en/distributed_monitoring.html
We probably want "Cascading Livestatus".