Disallow the use of legacy addons

Author: hakman

addons/README.md

@@ -1,3 +1,5 @@
 ## Addons
 
-Read on [addons](../docs/addons.md)
+**Legacy addons are deprecated and unmaintained!!!**
+
+Use [managed addons](../docs/addons.md) instead.

channels/pkg/cmd/apply_channel.go

@@ -26,7 +26,9 @@ import (
 
 	"github.com/blang/semver/v4"
 	"github.com/spf13/cobra"
+	"k8s.io/klog/v2"
 	"k8s.io/kops/channels/pkg/channels"
+	"k8s.io/kops/pkg/apis/kops/util"
 	"k8s.io/kops/util/pkg/tables"
 )
 
@@ -88,13 +90,20 @@ func RunApplyChannel(ctx context.Context, f Factory, out io.Writer, options *App
 			// We recognize the following "well-known" format:
 			// <name> with no slashes ->
 			if strings.Contains(name, "/") {
-				return fmt.Errorf("Channel format not recognized (did you mean to use `-f` to specify a local file?): %q", name)
+				return fmt.Errorf("channel format not recognized (did you mean to use `-f` to specify a local file?): %q", name)
 			}
 			expanded := "https://raw.githubusercontent.com/kubernetes/kops/master/addons/" + name + "/addon.yaml"
 			location, err = url.Parse(expanded)
 			if err != nil {
 				return fmt.Errorf("unable to parse expanded argument %q as url", expanded)
 			}
+			// Disallow the use of legacy addons from the "well-known" location starting Kubernetes 1.23:
+			// https://raw.githubusercontent.com/kubernetes/kops/master/addons/<name>/addon.yaml
+			if util.IsKubernetesGTE("1.23", kubernetesVersion) {
+				return fmt.Errorf("legacy addons are deprecated and unmaintained, use managed addons instead of %s", expanded)
+			} else {
+				klog.Warningf("Legacy addons are deprecated and unmaintained, use managed addons instead of %s", expanded)
+			}
 		}
 		o, err := channels.LoadAddons(name, location)
 		if err != nil {

docs/releases/1.22-NOTES.md

@@ -40,6 +40,8 @@ spec:
 
 * Support for Kubernetes versions 1.15 and 1.16 has been removed.
 
+* The legacy addons from `https://github.com/kubernetes/kops/tree/master/addons` have been deprecated and will not be available in Kubernetes 1.23+. Use [managed addons](https://kops.sigs.k8s.io/addons) instead.
+
 * The legacy location for downloads `s3://https://kubeupv2.s3.amazonaws.com/kops/` has been deprecated and will not be used for new releases. The new canonical downloads location is `https://artifacts.k8s.io/binaries/kops/`.
 
 * The `assets` phase of `kops update cluster` has been removed. It is replaced by the new `kops get assets --copy` command.
@@ -76,9 +78,7 @@ spec:
 
 * Support for Ubuntu 18.04 (Bionic) is deprecated and will be removed in future versions of kOps.
 
-* The [manifest based metrics server addon](https://github.com/kubernetes/kops/tree/master/addons/metrics-server) has been deprecated in favour of a configurable addon.
-
-* The [manifest based cluster autoscaler addon](https://github.com/kubernetes/kops/tree/master/addons/cluster-autoscaler) has been deprecated in favour of a configurable addon.
+* All legacy addons are deprecated in favor of managed addons, including the [metrics server addon](https://github.com/kubernetes/kops/tree/master/addons/metrics-server) and the [autoscaler addon](https://github.com/kubernetes/kops/tree/master/addons/cluster-autoscaler).
 
 * The `node-role.kubernetes.io/master` and `kubernetes.io/role` labels are deprecated and might be removed from control plane nodes in kOps 1.23.