adding status to Admission Controller

vertical-pod-autoscaler/deploy/vpa-rbac.yaml

@@ -264,6 +264,16 @@ rules:
       - get
       - list
       - watch
+  - apiGroups:
+      - "coordination.k8s.io"
+    resources:
+      - leases
+    verbs:
+      - create
+      - update
+      - get
+      - list
+      - watch
 ---
 apiVersion: rbac.authorization.k8s.io/v1
 kind: ClusterRoleBinding

vertical-pod-autoscaler/go.mod

@@ -5,6 +5,7 @@ go 1.12
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/golang/mock v1.3.1
+	github.com/google/uuid v1.1.1
 	github.com/prometheus/client_golang v0.9.2
 	github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4 // indirect
 	github.com/prometheus/common v0.4.1 // indirect

vertical-pod-autoscaler/go.sum

@@ -76,6 +76,7 @@ github.com/google/gofuzz v1.0.0 h1:A8PeW59pxE9IoFRqBp37U+mSNaQoZ46F1f0f863XSXw=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
 github.com/google/pprof v0.0.0-20181206194817-3ea8567a2e57/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
+github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gnostic v0.0.0-20170729233727-0c5108395e2d h1:7XGaL1e6bYS1yIonGp9761ExpPPV1ui0SAC59Yube9k=

vertical-pod-autoscaler/pkg/admission-controller/logic/status_updater.go

@@ -0,0 +1,77 @@
+/*
+Copyright 2020 The Kubernetes 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 logic
+
+import (
+	"time"
+
+	"k8s.io/autoscaler/vertical-pod-autoscaler/pkg/utils/status"
+	clientset "k8s.io/client-go/kubernetes"
+	"k8s.io/klog"
+)
+
+const (
+	// VpaAdmissionControllerStatusName is the name of
+	// the Admission Controller status object.
+	VpaAdmissionControllerStatusName = "vpa-admission-controller"
+	// VpaAdmissionControllerStatusNamespace is the namespace of
+	// the Admission Controller status object.
+	VpaAdmissionControllerStatusNamespace = "kube-system"
+
+	updateInterval = 10 * time.Second
+)
+
+// StatusUpdater periodically updates Admission Controller status.
+type StatusUpdater struct {
+	client *status.Client
+	stopCh chan struct{}
+}
+
+// NewStatusUpdater returns a new status updater.
+func NewStatusUpdater(c clientset.Interface, holderIdentity string) *StatusUpdater {
+	return &StatusUpdater{
+		client: status.NewClient(
+			c,
+			VpaAdmissionControllerStatusName,
+			VpaAdmissionControllerStatusNamespace,
+			updateInterval,
+			holderIdentity,
+		),
+		stopCh: make(chan struct{}),
+	}
+}
+
+// Start starts status updates.
+func (su *StatusUpdater) Start() {
+	go func() {
+		for {
+			select {
+			case <-su.stopCh:
+				return
+			case <-time.After(updateInterval):
+				if err := su.client.UpdateStatus(); err != nil {
+					klog.Errorf("Admission Controller status update failed: %v", err)
+				}
+			}
+		}
+	}()
+}
+
+// Stop stops status updates.
+func (su *StatusUpdater) Stop() {
+	close(su.stopCh)
+}

vertical-pod-autoscaler/pkg/admission-controller/main.go

@@ -89,6 +89,13 @@ func main() {
 	}
 	recommendationProvider := logic.NewRecommendationProvider(limitRangeCalculator, vpa_api_util.NewCappingRecommendationProcessor(limitRangeCalculator), targetSelectorFetcher, vpaLister)
 
+	hostname, err := os.Hostname()
+	if err != nil {
+		klog.Fatalf("Unable to get hostname: %v", err)
+	}
+	statusUpdater := logic.NewStatusUpdater(kubeClient, hostname)
+	defer statusUpdater.Stop()
+
 	as := logic.NewAdmissionServer(recommendationProvider, podPreprocessor, vpaPreprocessor, limitRangeCalculator)
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		as.Serve(w, r)
@@ -100,6 +107,10 @@ func main() {
 		TLSConfig: configTLS(clientset, certs.serverCert, certs.serverKey),
 	}
 	url := fmt.Sprintf("%v:%v", *webhookAddress, *webhookPort)
-	go selfRegistration(clientset, certs.caCert, &namespace, url, *registerByURL)
+	go func() {
+		selfRegistration(clientset, certs.caCert, &namespace, url, *registerByURL)
+		// Start status updates after the webhook is initialized.
+		statusUpdater.Start()
+	}()
 	server.ListenAndServeTLS("", "")
 }