Prevent duplicate BMC Addresses for BareMetalHosts

What does this MR do and why?

This MR introduces a Kyverno ClusterPolicy which ensures that each BareMetalHost resource has a unique BMC address across all namespaces. The purpose of this policy is to ensure that each machine is uniquely identified and managed without conflict. The logic behind the policy operates during admission, specifically when a BMH resource is created or updated. When a request is received, the policy performs an API call to retrieve all existing BMH resources in the cluster. It then evaluates whether the BMC address of the incoming BMH already exists on another BMH, excluding the current resource itself. If a duplicate is detected, the operation is denied.

This MR depends on sylva-projects/sylva-elements/helm-charts/sylva-capi-cluster!751 (merged)

Related reference(s)

Closes #2311 (closed)

Test coverage

This was tested in a CAPM3 environment. When a duplicate BMC address is found, the policy will deny the creation of it:

Error from server: error when creating "test.yaml": admission webhook "validate.kyverno.svc-fail" denied the request:

resource BareMetalHost/test-ns-2/server-b was blocked due to the following policies

prevent-duplicate-bmc-addresses:
  check-duplicate-bmc-address: BMC address 'redfish-virtualmedia://192.168.199.34:5000/redfish/v1/Systems/s4bmh-1'
    is already in use by another BareMetalHost. Each BMC address must be unique across
    all namespaces to prevent conflicts and potential node destruction.

CI configuration

Below you can choose test deployment variants to run in this MR's CI.

Click to open to CI configuration

Legend:

Icon	Meaning	Available values
☁️	Infra Provider	capd, capo, capm3
🚀	Bootstrap Provider	kubeadm (alias kadm), rke2
🐧	Node OS	ubuntu, suse
🛠️	Deployment Options	light-deploy, dev-sources, ha, misc, maxsurge-0, logging, no-logging
🎬	Pipeline Scenarios	Available scenario list and description

• 🎬 preview ☁️ capd 🚀 kadm 🐧 ubuntu

• 🎬 preview ☁️ capo 🚀 rke2 🐧 suse

• 🎬 preview ☁️ capm3 🚀 rke2 🐧 ubuntu

• ☁️ capd 🚀 kadm 🛠️ light-deploy 🐧 ubuntu

• ☁️ capd 🚀 rke2 🛠️ light-deploy 🐧 suse

• ☁️ capo 🚀 rke2 🐧 suse

• ☁️ capo 🚀 kadm 🐧 ubuntu

• ☁️ capo 🚀 rke2 🎬 rolling-update 🛠️ ha 🐧 ubuntu

• ☁️ capo 🚀 kadm 🎬 wkld-k8s-upgrade 🐧 ubuntu

• ☁️ capo 🚀 rke2 🎬 rolling-update-no-wkld 🛠️ ha 🐧 suse

• ☁️ capo 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha 🐧 ubuntu

• ☁️ capo 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha,misc 🐧 ubuntu

• ☁️ capo 🚀 rke2 🛠️ ha,misc 🐧 ubuntu

• ☁️ capm3 🚀 rke2 🐧 suse

• ☁️ capm3 🚀 kadm 🐧 ubuntu

• ☁️ capm3 🚀 kadm 🎬 rolling-update-no-wkld 🛠️ ha,misc 🐧 ubuntu

• ☁️ capm3 🚀 rke2 🎬 wkld-k8s-upgrade 🛠️ ha 🐧 suse

• ☁️ capm3 🚀 kadm 🎬 rolling-update 🛠️ ha 🐧 ubuntu

• ☁️ capm3 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha 🐧 suse

• ☁️ capm3 🚀 rke2 🛠️ misc,ha 🐧 suse

• ☁️ capm3 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha,misc 🐧 suse

• ☁️ capm3 🚀 kadm 🎬 rolling-update 🛠️ ha 🐧 suse

• ☁️ capm3 🚀 ck8s 🎬 no-wkld 🛠️ light-deploy 🐧 ubuntu

Global config for deployment pipelines

• autorun pipelines
• allow failure on pipelines
• record sylvactl events

Notes:

• Enabling autorun will make deployment pipelines to be run automatically without human interaction
• Disabling allow failure will make deployment pipelines mandatory for pipeline success.
• if both autorun and allow failure are disabled, deployment pipelines will need manual triggering but will be blocking the pipeline

Be aware: after configuration change, pipeline is not triggered automatically. Please run it manually (by clicking the run pipeline button in Pipelines tab) or push new code.