Add user facing doc for management-components upgrade

docs/content/en/docs/clustermgmt/cluster-upgrades/management-components-upgrade.md

@@ -0,0 +1,71 @@
+---
+title: "Upgrade management components"
+linkTitle: "Upgrade management components"
+weight: 21
+aliases:
+    /docs/tasks/cluster/cluster-upgrades/management-components-upgrade/
+date: 2024-02-21
+description: >
+  How to perform management components upgrade for management clusters
+---
+
+>**_NOTE:_** `upgrade management-components` sub-command is added in `eksctl anywhere` version `v0.19.0` for all providers. Management components upgrade can only be done through `eksctl-anywhere` cli, not through Kubernetes API.
+
+### What are “management components”?
+
+Management components are the k8s resources in an EKSA management cluster that are responsible for managing the EKS-A clusters' lifecycle. Key components include, but are not limited to:
+
+* The `eksa-controller-manager` pod located in the `eksa-system` namespace.
+* Tinkerbell services located in a bare metal management cluster.
+* Custom Resource Definitions (CRDs) such as `clusters`, `eksareleases`, and `tinkerbellmachineconfigs`.
+
+### Why upgrade management-components separately?
+
+The “upgrade cluster” command, when executed against a management cluster, not only upgrades its management components but also initiates a comprehensive upgrade of the management cluster itself. This process often entails node replacement and significant operational tasks, which might be deemed risky for some production environments due to the potential of replacing all Kubernetes nodes. 
+
+However, to leverage enhancements of newer EKSA version, such as bug fixes in the new management components without the extensive risk, it's advisable to initially upgrade only the management components. This step ensures minimal disruption and risk. Subsequently, you can proceed to upgrade the workload cluster at a more convenient time, once you're confident in the stability and readiness of your environment. This strategy provides a more controlled and efficient method to update your cluster's management infrastructure, aligning upgrades with your readiness and risk tolerance levels.
+
+### Check management components versions
+
+You can check the current and new versions of management components with the `upgrade plan management-components` command:
+
+```
+eksctl anywhere upgrade plan management-components -f management-cluster.yaml
+```
+
+The output should appear similar to the following:
+
+```
+NAME                 CURRENT VERSION       NEXT VERSION
+EKS-A Management     v0.18.3+cc70180       v0.19.0+a672f31
+cert-manager         v1.13.0+68bec33       v1.13.2+a34c207
+cluster-api          v1.5.2+b14378d        v1.6.0+04c07bc
+kubeadm              v1.5.2+5762149        v1.6.0+5bf0931
+vsphere              v1.7.4+6ecf386        v1.8.5+650acfa
+etcdadm-bootstrap    v1.0.10+c9a5a8a       v1.0.10+1ceb898
+etcdadm-controller   v1.0.16+0ed68e6       v1.0.17+5e33062
+```
+
+Alternatively, you can run `upgrade plan cluster` command against your management cluster, which should give you the version differences for both management and non-management components.
+
+### Perform management components upgrade
+
+To perform the upgrade, run the following command:
+
+```
+eksctl anywhere upgrade management-components -f management-cluster.yaml
+```
+
+The output should appear similar to the following:
+
+```
+Performing setup and validations
+✅ Docker provider validation
+✅ Control plane ready
+✅ Cluster CRDs ready
+Upgrading core components
+Installing new eksa components
+🎉 Management components upgraded!
+```
+
+At this point, a new `eksaVersion` will be available in your management cluster. If you want to upgrade your workload cluster, you can still run "eksctl anywhere upgrade cluster" or simply edit your workload cluster's `eksaVersion` field and apply it.