Add BM gardener documentation (#85)

Author: afritzler

docs/.vitepress/config.mts

@@ -125,7 +125,6 @@ export default withMermaid({
           { text: 'Overview', link: '/baremetal/architecture' },
           { text: 'Discovery', link: '/baremetal/architecture/discovery' },
           { text: 'Provisioning', link: '/baremetal/architecture/provisioning' },
-          { text: 'Maintenance', link: '/baremetal/architecture/maintenance' },
         ],
       },
       {

docs/baremetal/kubernetes/capi.md

@@ -1,8 +1,8 @@
 # Cluster API (CAPI) for IronCore Bare Metal
 
-The Cluster API (CAPI) for IronCore bare metal is a project that provides a declarative way to manage bare metal
-Kubernetes clusters using the Cluster API framework. It maps the CAPI concepts to the IronCore's `metal-operator` 
-API types.
+The [Cluster API (CAPI) for IronCore bare metal](https://github.com/ironcore-dev/cluster-api-provider-ironcore-metal) 
+is a project that provides a declarative way to manage bare metal Kubernetes clusters using the Cluster API framework. 
+It maps the CAPI concepts to the IronCore's `metal-operator` API types.
 
 The diagram below illustrates the architecture of the Cluster API for IronCore bare metal:
 

docs/baremetal/kubernetes/gardener.md

@@ -1 +1,28 @@
 # Gardener Integration with IronCore Bare Metal
+
+Apart from the [Cluster API Provider for Bare Metal](/baremetal/kubernetes/capi), IronCore is also integrated with 
+[Gardener](https://gardener.cloud), a Kubernetes-native project for managing Kubernetes clusters at scale.
+
+There are two main components in the Gardener integration with IronCore:
+- **Machine Controller Manager (MCM)**: This component is responsible for managing the lifecycle of machines in a 
+    Kubernetes cluster. It uses the `metal-operator` API types to provision and manage bare metal servers.
+- **Gardener Extension Provider**: This component provides the necessary integration points for Gardener to manage bare 
+    metal clusters.
+
+## Machine Controller Manager (MCM)
+
+The `[machine-controller-manager-provider-ironcore](https://github.com/ironcore-dev/machine-controller-manager-provider-ironcore-metal)`
+is responsible for managing the lifecycle of `Nodes` in a Kubernetes cluster. Here the MCM in essence is translating
+Gardener `Machine` resource to `ServerClaims` and wrapping the `user-data` coming from the Gardner OS extensions into
+an Ignition `Secret`.
+
+## Gardener Extension Provider
+
+The [`gardener-extension-provider-ironcore-metal`](https://github.com/ironcore-dev/gardener-extension-provider-ironcore-metal)
+is responsible for providing the necessary integration points for Gardener to manage bare metal clusters.
+
+Those integration points include:
+- Configure and the [Cloud Controller Manager](/baremetal/kubernetes/cloud-controller-manager) to handle the `Node` lifecycle
+and topology information.
+- Configure the [metal-load-balancer-controller](/baremetal/kubernetes/metal-loadbalancer-controller) to handle `Service` of type `LoadBalancer`.
+- Configure the [Machine Controller Manager (MCM)](#machine-controller-manager-mcm) to manage the creation of `Nodes` in the cluster.