Deploy metrics-server

Signed-off-by: Artiom Diomin <[email protected]>

config.yaml.dist

@@ -62,6 +62,10 @@ features:
   # AuditSink object.
   # More info: https://kubernetes.io/docs/tasks/debug-application-cluster/audit/#dynamic-backend
   enable_dynamic_audit_log: false
+
+  # Lever, to opt-out from deploying metrics-server
+  # more info: https://github.com/kubernetes-incubator/metrics-server
+  disable_metrics_server: false
 
 # The list of nodes can be overwritten by providing Terraform output.
 # You are strongly encouraged to provide an odd number of nodes and

examples/terraform/digitalocean/output.tf

@@ -40,9 +40,11 @@ output "kubeone_workers" {
     # following outputs will be parsed by kubeone and automatically merged into
     # corresponding (by name) worker definition
     fra1-1 = {
-      droplet_size  = "${var.droplet_size}"
-      region        = "${var.region}"
-      sshPublicKeys = ["${digitalocean_ssh_key.deployer.public_key}"]
+      replicas        = 3
+      operatingSystem = "ubuntu"
+      droplet_size    = "${var.droplet_size}"
+      region          = "${var.region}"
+      sshPublicKeys   = ["${digitalocean_ssh_key.deployer.public_key}"]
     }
   }
 }

pkg/config/cluster.go

@@ -337,6 +337,7 @@ func (m *WorkerConfig) Validate() error {
 type Features struct {
 	EnablePodSecurityPolicy bool `json:"enable_pod_security_policy"`
 	EnableDynamicAuditLog   bool `json:"enable_dynamic_audit_log"`
+	DisableMetricsServer    bool `json:"disable_metrics_server"`
 }
 
 // MachineControllerConfig controls

pkg/features/activate.go

@@ -31,6 +31,10 @@ func Activate(ctx *util.Context) error {
 		return errors.Wrap(err, "failed to install PodSecurityPolicy")
 	}
 
+	if err := installMetricsServer(!ctx.Cluster.Features.DisableMetricsServer, ctx); err != nil {
+		return errors.Wrap(err, "failed to install metrics-server")
+	}
+
 	return nil
 }
 

pkg/features/metrics-server.go

@@ -0,0 +1,30 @@
+/*
+Copyright 2019 The KubeOne Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package features
+
+import (
+	"github.com/kubermatic/kubeone/pkg/templates/metricsserver"
+	"github.com/kubermatic/kubeone/pkg/util"
+)
+
+func installMetricsServer(activate bool, ctx *util.Context) error {
+	if !activate {
+		return nil
+	}
+
+	return metricsserver.Deploy(ctx)
+}

pkg/templates/metricsserver/deployment.go

@@ -207,7 +207,6 @@ func metricsServerDeployment() *appsv1.Deployment {
 							Image:           "k8s.gcr.io/metrics-server-amd64:v0.3.1",
 							ImagePullPolicy: corev1.PullIfNotPresent,
 							Args: []string{
-								"--kubelet-preferred-address-types=Hostname",
 								"--kubelet-insecure-tls",
 							},
 							VolumeMounts: []corev1.VolumeMount{