Support running addon resizer on the control plane

addon-resizer/go.mod

@@ -4,6 +4,7 @@ go 1.21
 
 require (
 	github.com/golang/glog v1.2.1
+	github.com/google/go-cmp v0.6.0
 	github.com/prometheus/client_model v0.6.1
 	github.com/prometheus/common v0.52.3
 	github.com/spf13/pflag v1.0.5
@@ -16,21 +17,25 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/emicklei/go-restful/v3 v3.11.0 // indirect
+	github.com/evanphx/json-patch v4.12.0+incompatible // indirect
 	github.com/go-logr/logr v1.3.0 // indirect
 	github.com/go-openapi/jsonpointer v0.19.6 // indirect
 	github.com/go-openapi/jsonreference v0.20.2 // indirect
 	github.com/go-openapi/swag v0.22.3 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/google/gnostic-models v0.6.8 // indirect
 	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/google/uuid v1.3.0 // indirect
+	github.com/imdario/mergo v0.3.6 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	golang.org/x/net v0.23.0 // indirect
 	golang.org/x/oauth2 v0.18.0 // indirect
 	golang.org/x/sys v0.18.0 // indirect

addon-resizer/go.sum

@@ -4,6 +4,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/emicklei/go-restful/v3 v3.11.0 h1:rAQeMHw1c7zTmncogyy8VvRZwtkmkZ4FxERmMY4rD+g=
 github.com/emicklei/go-restful/v3 v3.11.0/go.mod h1:6n3XBCmQQb25CM2LCACGz8ukIrRry+4bhvbpWn3mrbc=
+github.com/evanphx/json-patch v4.12.0+incompatible h1:4onqiflcdA9EOZ4RxV643DvftH5pOlLGNtQ5lPWQu84=
+github.com/evanphx/json-patch v4.12.0+incompatible/go.mod h1:50XU6AFN0ol/bzJsmQLiYLvXMP4fmwYFNcr97nuDLSk=
 github.com/go-logr/logr v1.3.0 h1:2y3SDp0ZXuc6/cjLSZ+Q3ir+QB9T/iG5yYRXqsagWSY=
 github.com/go-logr/logr v1.3.0/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
 github.com/go-openapi/jsonpointer v0.19.6 h1:eCs3fxoIi3Wh6vtgmLTOjdhSpiqphQ+DaPn38N2ZdrE=
@@ -18,6 +20,8 @@ github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
 github.com/golang/glog v1.2.1 h1:OptwRhECazUx5ix5TTWC3EZhsZEHWcYWY4FQHTIubm4=
 github.com/golang/glog v1.2.1/go.mod h1:6AhwSGph0fcJtXVM/PEHPqZlFeoLxhs7/t5UDAwmO+w=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l8iNU+DwB5epxmsaqB+rhGL0m5jtYqE=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
@@ -33,6 +37,8 @@ github.com/google/pprof v0.0.0-20210720184732-4bb14d4b1be1 h1:K6RDEckDVWvDI9JAJY
 github.com/google/pprof v0.0.0-20210720184732-4bb14d4b1be1/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/imdario/mergo v0.3.6 h1:xTNEAn+kxVO7dTZGu0CegyqKZmoWFI0rF8UxjlB2d28=
+github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
@@ -59,6 +65,8 @@ github.com/onsi/ginkgo/v2 v2.13.0 h1:0jY9lJquiL8fcf3M4LAXN5aMlS/b2BV86HFFPCPMgE4
 github.com/onsi/ginkgo/v2 v2.13.0/go.mod h1:TE309ZR8s5FsKKpuB1YAQYBzCaAfUgatB/xlT/ETL/o=
 github.com/onsi/gomega v1.29.0 h1:KIA/t2t5UBzoirT4H9tsML45GEbo3ouUnBHsCfD2tVg=
 github.com/onsi/gomega v1.29.0/go.mod h1:9sxs+SwGrKI0+PWe4Fxa9tFQQBG5xSsSbMXOI8PPpoQ=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=

addon-resizer/nanny/election.go

@@ -0,0 +1,91 @@
+/*
+Copyright 2016 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 nanny
+
+import (
+	"context"
+	"github.com/golang/glog"
+	"os"
+	"time"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/kubernetes/scheme"
+	typedcorev1 "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/client-go/tools/leaderelection"
+	"k8s.io/client-go/tools/leaderelection/resourcelock"
+	"k8s.io/client-go/tools/record"
+)
+
+// Config is the leader configuration.
+type Config struct {
+	// LeaseDuration is the duration that non-leader candidates will
+	// wait to force acquire leadership. This is measured against time of
+	// last observed ack.
+	LeaseDuration time.Duration
+	// RenewDeadline is the duration that the acting control plane will
+	// retry refreshing leadership before giving up.
+	RenewDeadline time.Duration
+	// RetryPeriod is the duration to wait between tries of actions.
+	RetryPeriod time.Duration
+	// SystemNamespace is the namespace to use for the Endpoints lock.
+	SystemNamespace string
+}
+
+// LeadOrDie participates in leader election. If it wins leadership it executes doLead.
+// If it loses leadership it terminates the program.
+func LeadOrDie(cfg Config, clientset kubernetes.Interface, doLead func()) {
+	broadcaster := record.NewBroadcaster()
+	broadcaster.StartRecordingToSink(&typedcorev1.EventSinkImpl{Interface: typedcorev1.New(clientset.CoreV1().RESTClient()).Events("")})
+	recorder := broadcaster.NewRecorder(scheme.Scheme, corev1.EventSource{Component: "addon-resizer"})
+
+	hostname, err := os.Hostname()
+	if err != nil {
+		glog.Fatalf("Unable to get hostname: %v", err)
+	}
+
+	lock, err := resourcelock.New(
+		resourcelock.LeasesResourceLock,
+		cfg.SystemNamespace,
+		"addon-resizer",
+		clientset.CoreV1(),
+		clientset.CoordinationV1(),
+		resourcelock.ResourceLockConfig{
+			Identity:      hostname,
+			EventRecorder: recorder,
+		},
+	)
+	if err != nil {
+		glog.Fatalf("Unable to create leader election lock: %v", err)
+	}
+
+	leaderelection.RunOrDie(context.TODO(), leaderelection.LeaderElectionConfig{
+		Lock:          lock,
+		LeaseDuration: cfg.LeaseDuration,
+		RenewDeadline: cfg.RenewDeadline,
+		RetryPeriod:   cfg.RetryPeriod,
+		Callbacks: leaderelection.LeaderCallbacks{
+			OnStartedLeading: func(_ context.Context) {
+				glog.Info("Started leading.")
+				doLead()
+			},
+			OnStoppedLeading: func() {
+				glog.Fatalf("Lost leadership.")
+			},
+		},
+	})
+}

addon-resizer/nanny/estimator.go

@@ -43,6 +43,15 @@ func (e LinearEstimator) scale(clusterSize uint64) *corev1.ResourceRequirements
 	return calculateResources(clusterSize, e.Resources)
 }
 
+// updatedResourceEstimator creates a copy of original estimator
+// with updated resources.
+func (e LinearEstimator) updatedResourceEstimator(resources []Resource) ResourceEstimator {
+	newEstimator := LinearEstimator{
+		Resources: resources,
+	}
+	return newEstimator
+}
+
 // ExponentialEstimator estimates resource requirements in a way that prevents
 // frequent updates but may end up with larger estimates than actually needed.
 type ExponentialEstimator struct {
@@ -68,6 +77,17 @@ func (e ExponentialEstimator) scale(clusterSize uint64) *corev1.ResourceRequirem
 	return calculateResources(n, e.Resources)
 }
 
+// updatedResourceEstimator creates a copy of original estimator
+// with updated resources.
+func (e ExponentialEstimator) updatedResourceEstimator(resources []Resource) ResourceEstimator {
+	newEstimator := ExponentialEstimator{
+		Resources:      resources,
+		MinClusterSize: e.MinClusterSize,
+		ScaleFactor:    e.ScaleFactor,
+	}
+	return newEstimator
+}
+
 // Generates and returns a resource value string describing the overhead when
 // running on a cluster with the given the cluster size. The per resource overhead
 // is taken from the Resource instance.
@@ -105,4 +125,4 @@ func calculateResources(clusterSize uint64, resources []Resource) *corev1.Resour
 		Limits:   limits,
 		Requests: requests,
 	}
-}
+}

addon-resizer/nanny/kubernetes_client.go

@@ -184,11 +184,24 @@ func (k *kubernetesClient) countResourcesThroughMetrics(resourceName string) (ui
 }
 
 func (k *kubernetesClient) ContainerResources() (*corev1.ResourceRequirements, error) {
-	pod, err := k.clientset.CoreV1().Pods(k.namespace).Get(context.Background(), k.pod, metav1.GetOptions{})
-	if err != nil {
-		return nil, err
+	var containers []corev1.Container
+	// When addon resizer runs in a different pod, it cannot get pod name from env,
+	// so the pod name will be empty. In that case, get container information
+	// from the deployment instead.
+	if k.pod == "" {
+		dep, err := k.clientset.AppsV1().Deployments(k.namespace).Get(context.Background(), k.deployment, metav1.GetOptions{})
+		if err != nil {
+			return nil, err
+		}
+		containers = dep.Spec.Template.Spec.Containers
+	} else {
+		pod, err := k.clientset.CoreV1().Pods(k.namespace).Get(context.Background(), k.pod, metav1.GetOptions{})
+		if err != nil {
+			return nil, err
+		}
+		containers = pod.Spec.Containers
 	}
-	for _, container := range pod.Spec.Containers {
+	for _, container := range containers {
 		if container.Name == k.container {
 			return &container.Resources, nil
 		}
@@ -272,4 +285,4 @@ func NewKubernetesClient(namespace, deployment, pod, container string, clientset
 		useMetrics: useMetrics,
 	}
 	return result
-}
+}