Merge pull request #19 from sparkfabrik/fix/doc_for_4.0.0_upgrade

fix(documentation): update documentation for 4.0.0 upgrade

CHANGELOG.md

@@ -17,6 +17,14 @@ In the previous version, if the `prometheus_adapter_chart_version` variable was
 
 **If you are not using the Prometheus Adapter (you do not specify the `prometheus_adapter_chart_version` variable in your configuration)**, you can safely ignore this breaking change.
 
+If you receive the following error message during the upgrade:
+
+```bash
+cannot patch "kube-prometheus-stack-prometheus-node-exporter" with kind DaemonSet: DaemonSet.apps "kube-prometheus-stack-prometheus-node-exporter" is invalid: spec.selector: Invalid value: v1.LabelSelector{MatchLabels:map[string]string{"app.kubernetes.io/instance":"kube-prometheus-stack", "app.kubernetes.io/name":"prometheus-node-exporter"}, MatchExpressions:[]v1.LabelSelectorRequirement(nil)}: field is immutable
+```
+
+you can delete the `DaemonSet` (`kubectl delete daemonsets kube-prometheus-stack-prometheus-node-exporter`) resource and apply the changes again. The helm release will recreate the `DaemonSet` resource with the correct selector. The only drawback is that you will lose the metrics collected by the `DaemonSet` during the downtime.
+
 ### Added
 
 - Add the default versions for `prometheus_stack_chart_version` and `prometheus_adapter_chart_version` variables. These values indicate the default chart version to use and the reference to the shipped chart values.

README.md

@@ -65,13 +65,13 @@ module "kube_prometheus_stack" {
 }
 ```
 
-# Upgrading from 3.X.Y to 4.0.0
+# Upgrading from 3.Y.Z to 4.0.0
 
 For the upgrading note, see the [CHANGELOG](./CHANGELOG.md#400---2024-05-31) note for the `4.0.0` release.
 
-# Upgrading from 2.X.Y to 3.0.0
+# Upgrading from 2.Y.Z to 3.0.0
 
-Upgrading to `3.0.0` from `2.X.Y` will cause the destruction of the namespace and the basic auth secret.
+Upgrading to `3.0.0` from `2.Y.Z` will cause the destruction of the namespace and the basic auth secret.
 You will need to remove these resources from the state and import them in the new `v1` resources.
 
 ```bash