Add `BMCSettings` type and controller

[nagadeesh-nagaraja]

Summary

Create a out-of-band-Management Settings CRD (named BMCSetting) for BMC settings and implement the controller for it.

for each vendor, the settings might be different.
Example for Dell:
redfish/v1/Managers/iDRAC.Embedded.1/Oem/Dell/DellAttributes/System.Embedded.1

will need enhancement to the bmc interface in the repo to be able to get, check and set bmc attributes for a given vendor.

Basic example

• user provides the settings as key value pair for strings.
• Controller gets the current values of the attributes provided by the user through redfish APIs
  • note: the APIs are different for each vendor
  • might be useful to make a local copy of the setting attributes if vendor does not provide a straightforward list. to avoid calling multiple BMC API calls.
• Controller checks the possible attributes, its type, values allowed, based on best effort basis from the attribute type.
• Controller sets the attributes with redfish APIs.
  • note: the APIs are different for each vendor

Example CRD Spec

apiVersion: metal.ironcore.dev/v1alpha1
kind: BMCSettings
metadata:
  labels:
    app.kubernetes.io/name: metal-operator
    app.kubernetes.io/managed-by: kustomize
  name: bmcsetting-sample
spec:
  serverRef:
    name: server-01  # References an existing Server resource
  BMCSettingsSpec:
    version: 2.10.2
    settings:
      key1 : value1
      key2: value2
  BMCRef:
    name: BMC-01  # References an existing BMC resource
 serverRefList:
   - name: server-01
   - name: server-02
  serverMaintenancePolicyType:  # Policy an defined in  ServerMaintenance resource
  serverMaintenanceRef:
    name: server-maintenance-01  # References an existing ServerMaintenance resource
status:
  state: "InProgress"  # overallStatus. Possible values: Pending, InProgress, Applied, Failed

Motivation

Provide Ability to set BMC settings (outOfBandManagers Settings through controller)

[nagadeesh-nagaraja]

This workflow is similar to the bios setting update.

Reboot of BMC

Similar to BIOS Settings update #267, some of the settings update (or version upgrade) might need reboot of the BMC (not the server). we have the BMC CRD and controller, however it does not have functionality to reboot the BMC system. nor does it have the maintenance resource of its own.
possible options here :

• directly reset the BMC using the redfish API.
• introduce the "ensureServerPowerState" functionality/method in the bmc controller. --> we could possibly go with this if we don't envision any other major maintenance w.r.t BMC.
• can introduce the full maintenance CRD on the BMC resource.
• extend the serverMaintenance CRD to take ref for BMC or Server or any other type of resources.....
• is there any other possible solution which we can introduce?

Server/BMC Maintenance

Depending on the use-cases, there might be instances where the server (not BMC) needs to be put in maintenance as-well OR need owner approval to reboot (either BMC or server or both). is this a valid case?
furthermore, redfish API says multiple BMC are allowed for 1 server and wise versa.
That would mean we might have to put multiple servers in maintenance when the operations for a BMC is going on.

Possible solution here

• Ability to convey the user and get approval that the BMC or/and Server would be rebooted?
• Use serverMaintenanceSet and add capability to say what we are rebooting BMC or Serevr.
  Is there any other possible solution which we can introduce?