Merge pull request #903 from zalando-incubator/dependabot/go_modules/golang.org/x/crypto-0.52.0

Bump golang.org/x/crypto from 0.51.0 to 0.52.0

.github/workflows/ci.yaml

@@ -10,13 +10,13 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-go@v5
+    - uses: actions/checkout@v7.0.0
+    - uses: actions/setup-go@v6.5.0
       with:
-        go-version: '^1.25'
+        go-version: '^1.26'
     - run: go version
     - run: go install github.com/mattn/goveralls@latest
-    - run: go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+    - run: go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@latest
     - run: make build.docker
     - run: make test
     - run: make check

.github/workflows/codeql-analysis.yml

@@ -38,16 +38,16 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v7.0.0
 
     - name: setup go
-      uses: actions/setup-go@v5
+      uses: actions/setup-go@v6.5.0
       with:
-        go-version: '1.22'
+        go-version: '1.26'
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v3
+      uses: github/codeql-action/init@v4
       with:
         languages: ${{ matrix.language }}
         # If you wish to specify custom queries, you can do so here or in a config file.
@@ -61,7 +61,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v3
+      uses: github/codeql-action/autobuild@v4
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
@@ -74,4 +74,4 @@ jobs:
     #   ./location_of_script_within_repo/buildscript.sh
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v3
+      uses: github/codeql-action/analyze@v4

.github/workflows/gh-packages.yaml

@@ -25,15 +25,15 @@ jobs:
       packages: write # to push packages
     steps:
       - name: Checkout
-        uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9
+        uses: actions/checkout@4f1f4aec02e41874fa0262ea8ff5172d7978ad1e
 
-      - uses: actions/setup-go@fac708d6674e30b6ba41289acaab6d4b75aa0753
+      - uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16
         with:
           # https://www.npmjs.com/package/semver#caret-ranges-123-025-004
-          go-version: '^1.25'
+          go-version: '^1.26'
 
       - name: Login to Github Container Registry
-        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        uses: docker/login-action@650006c6eb7dba73a995cc03b0b2d7f5ca915bee
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
@@ -47,21 +47,21 @@ jobs:
           make build.linux.amd64 build.linux.arm64
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@2b82ce82d56a2a04d2637cd93a637ae1b359c0a7
+        uses: docker/setup-qemu-action@06116385d9baf250c9f4dcb4858b16962ea869c3
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@4c0219f9ac95b02789c1075625400b2acbff50b1
+        uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5
 
       - name: Login to GitHub Container Registry
         if: github.event_name != 'pull_request'
-        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        uses: docker/login-action@650006c6eb7dba73a995cc03b0b2d7f5ca915bee
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Docker meta
-        uses: docker/metadata-action@818d4b7b91585d195f67373fd9cb0332e31a7175
+        uses: docker/metadata-action@80c7e94dd9b9319bd5eb7a0e0fe9291e23a2a2e9
         id: meta
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
@@ -70,10 +70,9 @@ jobs:
             type=semver,pattern=v{{major}}.{{minor}}
 
       - name: Build and push
-        uses: docker/build-push-action@2eb1c1961a95fc15694676618e422e8ba1d63825
+        uses: docker/build-push-action@f9f3042f7e2789586610d6e8b85c8f03e5195baf
         with:
           context: .
-          build-args: BASE_IMAGE=gcr.io/distroless/static-debian12
           platforms: linux/amd64,linux/arm64
           push: ${{ github.event_name != 'pull_request' && startsWith(github.ref, 'refs/tags/v') }}
           tags: ${{ steps.meta.outputs.tags }}
@@ -81,10 +80,9 @@ jobs:
 
       # Build and push latest tag
       - name: Build and push latest
-        uses: docker/build-push-action@2eb1c1961a95fc15694676618e422e8ba1d63825
+        uses: docker/build-push-action@f9f3042f7e2789586610d6e8b85c8f03e5195baf
         with:
           context: .
-          build-args: BASE_IMAGE=gcr.io/distroless/static-debian12
           platforms: linux/amd64,linux/arm64
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest

.github/workflows/release-chart.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v7.0.0
         with:
           fetch-depth: 0
 
@@ -20,7 +20,7 @@ jobs:
           git config user.email "$GITHUB_ACTOR@users.noreply.github.com"
 
       - name: Run chart-releaser
-        uses: helm/chart-releaser-action@v1.4.0
+        uses: helm/chart-releaser-action@v1.7.0
         with:
           charts_dir: docs
         env:

.golangci.yml

@@ -1,13 +1,29 @@
+version: "2"
 run:
   concurrency: 4
-
 linters:
-  disable-all: true
+  default: none
   enable:
-  - errcheck
-  - gosimple
-  - govet
-  - ineffassign
-  - staticcheck
-  - typecheck
-  - unused
+    - errcheck
+    - govet
+    - ineffassign
+    - staticcheck
+    - unused
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

Dockerfile

@@ -1,4 +1,4 @@
-ARG BASE_IMAGE=registry.opensource.zalan.do/library/static:latest
+ARG BASE_IMAGE=gcr.io/distroless/static-debian12:latest
 FROM ${BASE_IMAGE}
 LABEL maintainer="Team Teapot @ Zalando SE <team-teapot@zalando.de>"
 

Makefile

@@ -2,7 +2,7 @@
 
 BINARY        ?= kube-metrics-adapter
 VERSION       ?= $(shell git describe --tags --always --dirty)
-IMAGE         ?= registry-write.opensource.zalan.do/teapot/$(BINARY)
+IMAGE         ?= ghcr.io/zalando-incubator/$(BINARY)
 TAG           ?= $(VERSION)
 SOURCES       = $(shell find . -name '*.go')
 DOCKERFILE    ?= Dockerfile
@@ -34,12 +34,12 @@ $(GENERATED): go.mod $(CRD_TYPE_SOURCE) $(OPENAPI)
 	./hack/update-codegen.sh
 
 $(GENERATED_CRDS): $(GENERATED) $(CRD_SOURCES)
-	go run sigs.k8s.io/controller-tools/cmd/controller-gen crd:crdVersions=v1 paths=./pkg/apis/... output:crd:dir=docs
+	go tool controller-gen crd:crdVersions=v1 paths=./pkg/apis/... output:crd:dir=docs
 	mv docs/zalando.org_clusterscalingschedules.yaml docs/cluster_scaling_schedules_crd.yaml
 	mv docs/zalando.org_scalingschedules.yaml docs/scaling_schedules_crd.yaml
 
 $(OPENAPI): go.mod
-	go run k8s.io/kube-openapi/cmd/openapi-gen \
+	go tool openapi-gen \
 		--go-header-file hack/boilerplate.go.txt \
 		--logtostderr \
 		--output-dir pkg/api/generated/openapi \

delivery.yaml

@@ -15,21 +15,6 @@ pipeline:
   - desc: test
     cmd: |
       make test
-  - desc: build
-    cmd: |
-      make build.docker
-  - desc: push
-    cmd: |
-      if [[ $CDP_TARGET_BRANCH == master && ! $CDP_PULL_REQUEST_NUMBER ]]; then
-        IMAGE=registry-write.opensource.zalan.do/teapot/kube-metrics-adapter
-        VERSION=$(git describe --tags --always)
-      else
-        IMAGE=registry-write.opensource.zalan.do/teapot/kube-metrics-adapter-test
-        VERSION=$CDP_BUILD_VERSION
-      fi
-      IMAGE=$IMAGE VERSION=$VERSION make build.docker
-      git diff --stat --exit-code
-      IMAGE=$IMAGE VERSION=$VERSION make build.push
   - desc: Build and push image to Zalando's registry
     cmd: |
       if [[ $CDP_TARGET_BRANCH == master && ! $CDP_PULL_REQUEST_NUMBER ]]; then

docs/cluster_scaling_schedules_crd.yaml

@@ -3,7 +3,7 @@ apiVersion: apiextensions.k8s.io/v1
 kind: CustomResourceDefinition
 metadata:
   annotations:
-    controller-gen.kubebuilder.io/version: v0.17.3
+    controller-gen.kubebuilder.io/version: v0.19.0
   name: clusterscalingschedules.zalando.org
 spec:
   group: zalando.org

docs/helm/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v2
 name: kube-metrics-adapter
-version: 0.2.3
+version: 0.2.6
 description: kube-metrics-adapter helm chart
 home: https://github.com/zalando-incubator/kube-metrics-adapter
 maintainers:

docs/helm/templates/custom-metrics-apiservice.yaml

@@ -3,6 +3,13 @@ apiVersion: apiregistration.k8s.io/v1
 kind: APIService
 metadata:
   name: v1beta1.custom.metrics.k8s.io
+  {{- with .Values.customMetricsApi.annotations }}
+  annotations:
+    {{- range $k, $v := . }}
+      {{- $value := $v | quote }}
+      {{- printf "%s: %s" (tpl $k $) (tpl $value $) | nindent 4 }}
+    {{- end }}
+  {{- end }}
 spec:
   service:
     name: kube-metrics-adapter

docs/helm/templates/external-metrics-apiservice.yaml

@@ -3,6 +3,13 @@ apiVersion: apiregistration.k8s.io/v1
 kind: APIService
 metadata:
   name: v1beta1.external.metrics.k8s.io
+  {{- with .Values.externalMetricsApi.annotations }}
+  annotations:
+    {{- range $k, $v := . }}
+      {{- $value := $v | quote }}
+      {{- printf "%s: %s" (tpl $k $) (tpl $value $) | nindent 4 }}
+    {{- end }}
+  {{- end }}
 spec:
   service:
     name: kube-metrics-adapter

docs/helm/values.yaml

@@ -4,7 +4,7 @@ replicas: 1
 
 registry:
   image: ghcr.io/zalando-incubator/kube-metrics-adapter
-  imageTag: v0.2.3
+  imageTag: v0.2.6
   imagePullPolicy: IfNotPresent
 
 service:
@@ -15,7 +15,19 @@ addDirectoryHeader:
 contentionProfiling:
 profiling:
 enableCustomMetricsApi: true
+
+# -- add annotations to the custom metrics apiservice resource, e.g.
+# cert-manager.io/inject-ca-from: {{.Release.Namespace}}/kube-metrics-adapter to inject the CA certificate form a cert-manager-issued cert used for the deployment
+customMetricsApi:
+  annotations: {}
+
 enableExternalMetricsApi: true
+
+# -- add annotations to the custom metrics apiservice resource, e.g.
+# cert-manager.io/inject-ca-from: {{.Release.Namespace}}/kube-metrics-adapter to inject the CA certificate form a cert-manager-issued cert used for the deployment
+externalMetricsApi:
+  annotations: {}
+
 credentialsDirectory:
 disregardIncompatibleHPAs:
 http2MaxStreamsPerConnection:

docs/scaling_schedules_crd.yaml

@@ -3,7 +3,7 @@ apiVersion: apiextensions.k8s.io/v1
 kind: CustomResourceDefinition
 metadata:
   annotations:
-    controller-gen.kubebuilder.io/version: v0.17.3
+    controller-gen.kubebuilder.io/version: v0.19.0
   name: scalingschedules.zalando.org
 spec:
   group: zalando.org

example/Dockerfile

@@ -1,7 +1,9 @@
-FROM registry.opensource.zalan.do/library/alpine-3:latest
+FROM gcr.io/distroless/static-debian12:latest
 LABEL maintainer="Team Teapot @ Zalando SE <team-teapot@zalando.de>"
 
+ARG TARGETARCH
+
 # add binary
-ADD build/linux/custom-metrics-consumer /
+ADD build/linux/${TARGETARCH}/custom-metrics-consumer /
 
 ENTRYPOINT ["/custom-metrics-consumer"]

example/Makefile

@@ -32,11 +32,14 @@ build/$(BINARY): $(SOURCES)
 build/linux/$(BINARY): $(SOURCES)
 	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/linux/$(BINARY) -ldflags "$(LDFLAGS)" .
 
+build/linux/amd64/$(BINARY): $(SOURCES)
+	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/linux/amd64/$(BINARY) -ldflags "$(LDFLAGS)" .
+
+build/linux/arm64/$(BINARY): $(SOURCES)
+	GOOS=linux GOARCH=arm64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/linux/arm64/$(BINARY) -ldflags "$(LDFLAGS)" .
+
 build/osx/$(BINARY): $(SOURCES)
 	GOOS=darwin GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/osx/$(BINARY) -ldflags "$(LDFLAGS)" .
 
-build.docker: build.linux
-	docker build --rm -t "$(IMAGE):$(TAG)" -f $(DOCKERFILE) .
-
-build.push: build.docker
-	docker push "$(IMAGE):$(TAG)"
+build.push: build/linux/amd64/$(BINARY) build/linux/arm64/$(BINARY)
+	docker buildx build --rm --build-arg -t "$(IMAGE):$(TAG)" --platform linux/amd64,linux/arm64 --push .

example/main.go

@@ -10,7 +10,7 @@ import (
 
 func metricsHandler(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(200)
-	_, err := w.Write([]byte(fmt.Sprintf(`{"queue": {"length": %d}}`, size)))
+	_, err := fmt.Fprintf(w, `{"queue": {"length": %d}}`, size)
 	if err != nil {
 		log.Fatalf("failed to write: %v", err)
 	}

hack/tools.go

@@ -1,23 +0,0 @@
-// +build tools
-
-/*
-Copyright 2019 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.
-*/
-
-// This package imports things required by build scripts, to force `go mod` to see them as dependencies
-package tools
-
-import (
-	_ "k8s.io/code-generator"
-	_ "k8s.io/kube-openapi/cmd/openapi-gen"
-	_ "sigs.k8s.io/controller-tools/cmd/controller-gen"
-)

hack/update-codegen.sh

@@ -31,14 +31,13 @@ APIS_PKG="${GOPKG}/pkg/apis"
 GROUPS_WITH_VERSIONS="${CUSTOM_RESOURCE_NAME}:${CUSTOM_RESOURCE_VERSION}"
 
 echo "Generating deepcopy funcs"
-go run k8s.io/code-generator/cmd/deepcopy-gen \
+go tool deepcopy-gen \
   --output-file zz_generated.deepcopy.go \
-  --bounding-dirs "${APIS_PKG}" \
   --go-header-file "${SCRIPT_ROOT}/hack/boilerplate.go.txt" \
   "${APIS_PKG}/${CUSTOM_RESOURCE_NAME}/${CUSTOM_RESOURCE_VERSION}"
 
 echo "Generating clientset for ${GROUPS_WITH_VERSIONS} at ${OUTPUT_PKG}/${CLIENTSET_PKG_NAME:-clientset}"
-go run k8s.io/code-generator/cmd/client-gen \
+go tool client-gen \
   --clientset-name versioned \
   --input-base "" \
   --input "${APIS_PKG}/${CUSTOM_RESOURCE_NAME}/${CUSTOM_RESOURCE_VERSION}" \
@@ -47,14 +46,14 @@ go run k8s.io/code-generator/cmd/client-gen \
   --output-dir "${OUTPUT_DIR}/clientset"
 
 echo "Generating listers for ${GROUPS_WITH_VERSIONS} at ${OUTPUT_PKG}/listers"
-go run k8s.io/code-generator/cmd/lister-gen \
+go tool lister-gen \
   --output-pkg "${OUTPUT_PKG}/listers" \
   --go-header-file "${SCRIPT_ROOT}/hack/boilerplate.go.txt" \
   --output-dir "${OUTPUT_DIR}/listers" \
   "${APIS_PKG}/${CUSTOM_RESOURCE_NAME}/${CUSTOM_RESOURCE_VERSION}"
 
 echo "Generating informers for ${GROUPS_WITH_VERSIONS} at ${OUTPUT_PKG}/informers"
-go run k8s.io/code-generator/cmd/informer-gen \
+go tool informer-gen \
   --versioned-clientset-package "${OUTPUT_PKG}/${CLIENTSET_PKG_NAME:-clientset}/${CLIENTSET_NAME_VERSIONED:-versioned}" \
   --listers-package "${OUTPUT_PKG}/listers" \
   --output-pkg "${OUTPUT_PKG}/informers" \

pkg/apis/zalando.org/v1/types.go

@@ -35,7 +35,7 @@ type ScalingSchedule struct {
 // Identifier returns the namespaced scalingScale Identifier in the format
 // `<namespace>/<name>`.
 func (s *ScalingSchedule) Identifier() string {
-	return s.ObjectMeta.Namespace + "/" + s.ObjectMeta.Name
+	return s.Namespace + "/" + s.Name
 }
 
 // ResourceSpec returns the ScalingScheduleSpec of the ScalingSchedule.
@@ -66,7 +66,7 @@ type ClusterScalingSchedule struct {
 // Identifier returns the cluster scalingScale Identifier in the format
 // `<name>`.
 func (s *ClusterScalingSchedule) Identifier() string {
-	return s.ObjectMeta.Name
+	return s.Name
 }
 
 // ResourceSpec returns the ScalingScheduleSpec of the ClusterScalingSchedule.

pkg/client/clientset/versioned/fake/clientset_generated.go

@@ -22,6 +22,7 @@ import (
 	clientset "github.com/zalando-incubator/kube-metrics-adapter/pkg/client/clientset/versioned"
 	zalandov1 "github.com/zalando-incubator/kube-metrics-adapter/pkg/client/clientset/versioned/typed/zalando.org/v1"
 	fakezalandov1 "github.com/zalando-incubator/kube-metrics-adapter/pkg/client/clientset/versioned/typed/zalando.org/v1/fake"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/client-go/discovery"
@@ -33,10 +34,6 @@ import (
 // It's backed by a very simple object tracker that processes creates, updates and deletions as-is,
 // without applying any field management, validations and/or defaults. It shouldn't be considered a replacement
 // for a real clientset and is mostly useful in simple unit tests.
-//
-// DEPRECATED: NewClientset replaces this with support for field management, which significantly improves
-// server side apply testing. NewClientset is only available when apply configurations are generated (e.g.
-// via --with-applyconfig).
 func NewSimpleClientset(objects ...runtime.Object) *Clientset {
 	o := testing.NewObjectTracker(scheme, codecs.UniversalDecoder())
 	for _, obj := range objects {
@@ -49,9 +46,13 @@ func NewSimpleClientset(objects ...runtime.Object) *Clientset {
 	cs.discovery = &fakediscovery.FakeDiscovery{Fake: &cs.Fake}
 	cs.AddReactor("*", "*", testing.ObjectReaction(o))
 	cs.AddWatchReactor("*", func(action testing.Action) (handled bool, ret watch.Interface, err error) {
+		var opts metav1.ListOptions
+		if watchAction, ok := action.(testing.WatchActionImpl); ok {
+			opts = watchAction.ListOptions
+		}
 		gvr := action.GetResource()
 		ns := action.GetNamespace()
-		watch, err := o.Watch(gvr, ns)
+		watch, err := o.Watch(gvr, ns, opts)
 		if err != nil {
 			return false, nil, err
 		}
@@ -78,6 +79,17 @@ func (c *Clientset) Tracker() testing.ObjectTracker {
 	return c.tracker
 }
 
+// IsWatchListSemanticsUnSupported informs the reflector that this client
+// doesn't support WatchList semantics.
+//
+// This is a synthetic method whose sole purpose is to satisfy the optional
+// interface check performed by the reflector.
+// Returning true signals that WatchList can NOT be used.
+// No additional logic is implemented here.
+func (c *Clientset) IsWatchListSemanticsUnSupported() bool {
+	return true
+}
+
 var (
 	_ clientset.Interface = &Clientset{}
 	_ testing.FakeClient  = &Clientset{}

pkg/client/clientset/versioned/typed/zalando.org/v1/zalando.org_client.go

@@ -50,9 +50,7 @@ func (c *ZalandoV1Client) ScalingSchedules(namespace string) ScalingScheduleInte
 // where httpClient was generated with rest.HTTPClientFor(c).
 func NewForConfig(c *rest.Config) (*ZalandoV1Client, error) {
 	config := *c
-	if err := setConfigDefaults(&config); err != nil {
-		return nil, err
-	}
+	setConfigDefaults(&config)
 	httpClient, err := rest.HTTPClientFor(&config)
 	if err != nil {
 		return nil, err
@@ -64,9 +62,7 @@ func NewForConfig(c *rest.Config) (*ZalandoV1Client, error) {
 // Note the http client provided takes precedence over the configured transport values.
 func NewForConfigAndClient(c *rest.Config, h *http.Client) (*ZalandoV1Client, error) {
 	config := *c
-	if err := setConfigDefaults(&config); err != nil {
-		return nil, err
-	}
+	setConfigDefaults(&config)
 	client, err := rest.RESTClientForConfigAndClient(&config, h)
 	if err != nil {
 		return nil, err
@@ -89,7 +85,7 @@ func New(c rest.Interface) *ZalandoV1Client {
 	return &ZalandoV1Client{c}
 }
 
-func setConfigDefaults(config *rest.Config) error {
+func setConfigDefaults(config *rest.Config) {
 	gv := zalandoorgv1.SchemeGroupVersion
 	config.GroupVersion = &gv
 	config.APIPath = "/apis"
@@ -98,8 +94,6 @@ func setConfigDefaults(config *rest.Config) error {
 	if config.UserAgent == "" {
 		config.UserAgent = rest.DefaultKubernetesUserAgent()
 	}
-
-	return nil
 }
 
 // RESTClient returns a RESTClient that is used to communicate

pkg/client/informers/externalversions/factory.go

@@ -19,6 +19,7 @@ limitations under the License.
 package externalversions
 
 import (
+	context "context"
 	reflect "reflect"
 	sync "sync"
 	time "time"
@@ -29,6 +30,7 @@ import (
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	runtime "k8s.io/apimachinery/pkg/runtime"
 	schema "k8s.io/apimachinery/pkg/runtime/schema"
+	wait "k8s.io/apimachinery/pkg/util/wait"
 	cache "k8s.io/client-go/tools/cache"
 )
 
@@ -43,6 +45,7 @@ type sharedInformerFactory struct {
 	defaultResync    time.Duration
 	customResync     map[reflect.Type]time.Duration
 	transform        cache.TransformFunc
+	informerName     *cache.InformerName
 
 	informers map[reflect.Type]cache.SharedIndexInformer
 	// startedInformers is used for tracking which informers have been started.
@@ -89,6 +92,21 @@ func WithTransform(transform cache.TransformFunc) SharedInformerOption {
 	}
 }
 
+// WithInformerName sets the InformerName for informer identity used in metrics.
+// The InformerName must be created via cache.NewInformerName() at startup,
+// which validates global uniqueness. Each informer type will register its
+// GVR under this name.
+func WithInformerName(informerName *cache.InformerName) SharedInformerOption {
+	return func(factory *sharedInformerFactory) *sharedInformerFactory {
+		factory.informerName = informerName
+		return factory
+	}
+}
+
+func (f *sharedInformerFactory) InformerName() *cache.InformerName {
+	return f.informerName
+}
+
 // NewSharedInformerFactory constructs a new instance of sharedInformerFactory for all namespaces.
 func NewSharedInformerFactory(client versioned.Interface, defaultResync time.Duration) SharedInformerFactory {
 	return NewSharedInformerFactoryWithOptions(client, defaultResync)
@@ -97,6 +115,7 @@ func NewSharedInformerFactory(client versioned.Interface, defaultResync time.Dur
 // NewFilteredSharedInformerFactory constructs a new instance of sharedInformerFactory.
 // Listers obtained via this SharedInformerFactory will be subject to the same filters
 // as specified here.
+//
 // Deprecated: Please use NewSharedInformerFactoryWithOptions instead
 func NewFilteredSharedInformerFactory(client versioned.Interface, defaultResync time.Duration, namespace string, tweakListOptions internalinterfaces.TweakListOptionsFunc) SharedInformerFactory {
 	return NewSharedInformerFactoryWithOptions(client, defaultResync, WithNamespace(namespace), WithTweakListOptions(tweakListOptions))
@@ -122,6 +141,10 @@ func NewSharedInformerFactoryWithOptions(client versioned.Interface, defaultResy
 }
 
 func (f *sharedInformerFactory) Start(stopCh <-chan struct{}) {
+	f.StartWithContext(wait.ContextForChannel(stopCh))
+}
+
+func (f *sharedInformerFactory) StartWithContext(ctx context.Context) {
 	f.lock.Lock()
 	defer f.lock.Unlock()
 
@@ -131,15 +154,9 @@ func (f *sharedInformerFactory) Start(stopCh <-chan struct{}) {
 
 	for informerType, informer := range f.informers {
 		if !f.startedInformers[informerType] {
-			f.wg.Add(1)
-			// We need a new variable in each loop iteration,
-			// otherwise the goroutine would use the loop variable
-			// and that keeps changing.
-			informer := informer
-			go func() {
-				defer f.wg.Done()
-				informer.Run(stopCh)
-			}()
+			f.wg.Go(func() {
+				informer.RunWithContext(ctx)
+			})
 			f.startedInformers[informerType] = true
 		}
 	}
@@ -152,9 +169,15 @@ func (f *sharedInformerFactory) Shutdown() {
 
 	// Will return immediately if there is nothing to wait for.
 	f.wg.Wait()
+	f.informerName.Release()
 }
 
 func (f *sharedInformerFactory) WaitForCacheSync(stopCh <-chan struct{}) map[reflect.Type]bool {
+	result := f.WaitForCacheSyncWithContext(wait.ContextForChannel(stopCh))
+	return result.Synced
+}
+
+func (f *sharedInformerFactory) WaitForCacheSyncWithContext(ctx context.Context) cache.SyncResult {
 	informers := func() map[reflect.Type]cache.SharedIndexInformer {
 		f.lock.Lock()
 		defer f.lock.Unlock()
@@ -168,10 +191,31 @@ func (f *sharedInformerFactory) WaitForCacheSync(stopCh <-chan struct{}) map[ref
 		return informers
 	}()
 
-	res := map[reflect.Type]bool{}
-	for informType, informer := range informers {
-		res[informType] = cache.WaitForCacheSync(stopCh, informer.HasSynced)
+	// Wait for informers to sync, without polling.
+	cacheSyncs := make([]cache.DoneChecker, 0, len(informers))
+	for _, informer := range informers {
+		cacheSyncs = append(cacheSyncs, informer.HasSyncedChecker())
 	}
+	cache.WaitFor(ctx, "" /* no logging */, cacheSyncs...)
+
+	res := cache.SyncResult{
+		Synced: make(map[reflect.Type]bool, len(informers)),
+	}
+	failed := false
+	for informType, informer := range informers {
+		hasSynced := informer.HasSynced()
+		if !hasSynced {
+			failed = true
+		}
+		res.Synced[informType] = hasSynced
+	}
+	if failed {
+		// context.Cause is more informative than ctx.Err().
+		// This must be non-nil, otherwise WaitFor wouldn't have stopped
+		// prematurely.
+		res.Err = context.Cause(ctx)
+	}
+
 	return res
 }
 
@@ -193,7 +237,9 @@ func (f *sharedInformerFactory) InformerFor(obj runtime.Object, newFunc internal
 	}
 
 	informer = newFunc(f.client, resyncPeriod)
-	informer.SetTransform(f.transform)
+	if f.transform != nil {
+		informer.SetTransform(f.transform)
+	}
 	f.informers[informerType] = informer
 
 	return informer
@@ -204,33 +250,52 @@ func (f *sharedInformerFactory) InformerFor(obj runtime.Object, newFunc internal
 //
 // It is typically used like this:
 //
-//	ctx, cancel := context.Background()
+//	ctx, cancel := context.WithCancel(context.Background())
 //	defer cancel()
 //	factory := NewSharedInformerFactory(client, resyncPeriod)
 //	defer factory.WaitForStop()    // Returns immediately if nothing was started.
 //	genericInformer := factory.ForResource(resource)
 //	typedInformer := factory.SomeAPIGroup().V1().SomeType()
-//	factory.Start(ctx.Done())          // Start processing these informers.
-//	synced := factory.WaitForCacheSync(ctx.Done())
-//	for v, ok := range synced {
-//	    if !ok {
-//	        fmt.Fprintf(os.Stderr, "caches failed to sync: %v", v)
-//	        return
-//	    }
+//	handle, err := typeInformer.Informer().AddEventHandler(...)
+//	if err != nil {
+//	    return fmt.Errorf("register event handler: %v", err)
+//	}
+//	defer typeInformer.Informer().RemoveEventHandler(handle) // Avoids leaking goroutines.
+//	factory.StartWithContext(ctx)                            // Start processing these informers.
+//	synced := factory.WaitForCacheSyncWithContext(ctx)
+//	if err := synced.AsError(); err != nil {
+//	    return err
+//	}
+//	for v := range synced {
+//	    // Only if desired log some information similar to this.
+//	    fmt.Fprintf(os.Stdout, "cache synced: %s", v)
+//	}
+//
+//	// Also make sure that all of the initial cache events have been delivered.
+//	if !WaitFor(ctx, "event handler sync", handle.HasSyncedChecker()) {
+//	    // Must have failed because of context.
+//	    return fmt.Errorf("sync event handler: %w", context.Cause(ctx))
 //	}
 //
 //	// Creating informers can also be created after Start, but then
 //	// Start must be called again:
 //	anotherGenericInformer := factory.ForResource(resource)
-//	factory.Start(ctx.Done())
+//	factory.StartWithContext(ctx)
 type SharedInformerFactory interface {
 	internalinterfaces.SharedInformerFactory
 
 	// Start initializes all requested informers. They are handled in goroutines
 	// which run until the stop channel gets closed.
 	// Warning: Start does not block. When run in a go-routine, it will race with a later WaitForCacheSync.
+	//
+	// Contextual logging: StartWithContext should be used instead of Start in code which supports contextual logging.
 	Start(stopCh <-chan struct{})
 
+	// StartWithContext initializes all requested informers. They are handled in goroutines
+	// which run until the context gets canceled.
+	// Warning: StartWithContext does not block. When run in a go-routine, it will race with a later WaitForCacheSync.
+	StartWithContext(ctx context.Context)
+
 	// Shutdown marks a factory as shutting down. At that point no new
 	// informers can be started anymore and Start will return without
 	// doing anything.
@@ -245,8 +310,14 @@ type SharedInformerFactory interface {
 
 	// WaitForCacheSync blocks until all started informers' caches were synced
 	// or the stop channel gets closed.
+	//
+	// Contextual logging: WaitForCacheSync should be used instead of WaitForCacheSync in code which supports contextual logging. It also returns a more useful result.
 	WaitForCacheSync(stopCh <-chan struct{}) map[reflect.Type]bool
 
+	// WaitForCacheSyncWithContext blocks until all started informers' caches were synced
+	// or the context gets canceled.
+	WaitForCacheSyncWithContext(ctx context.Context) cache.SyncResult
+
 	// ForResource gives generic access to a shared informer of the matching type.
 	ForResource(resource schema.GroupVersionResource) (GenericInformer, error)
 

pkg/client/informers/externalversions/internalinterfaces/factory_interfaces.go

@@ -34,7 +34,26 @@ type NewInformerFunc func(versioned.Interface, time.Duration) cache.SharedIndexI
 type SharedInformerFactory interface {
 	Start(stopCh <-chan struct{})
 	InformerFor(obj runtime.Object, newFunc NewInformerFunc) cache.SharedIndexInformer
+	InformerName() *cache.InformerName
 }
 
 // TweakListOptionsFunc is a function that transforms a v1.ListOptions.
 type TweakListOptionsFunc func(*v1.ListOptions)
+
+// InformerOptions holds the options for creating an informer.
+type InformerOptions struct {
+	// ResyncPeriod is the resync period for this informer.
+	// If not set, defaults to 0 (no resync).
+	ResyncPeriod time.Duration
+
+	// Indexers are the indexers for this informer.
+	Indexers cache.Indexers
+
+	// InformerName is used to uniquely identify this informer for metrics.
+	// If not set, metrics will not be published for this informer.
+	// Use cache.NewInformerName() to create an InformerName at startup.
+	InformerName *cache.InformerName
+
+	// TweakListOptions is an optional function to modify the list options.
+	TweakListOptions TweakListOptionsFunc
+}

pkg/client/informers/externalversions/zalando.org/v1/clusterscalingschedule.go

@@ -28,6 +28,7 @@ import (
 	zalandoorgv1 "github.com/zalando-incubator/kube-metrics-adapter/pkg/client/listers/zalando.org/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	runtime "k8s.io/apimachinery/pkg/runtime"
+	schema "k8s.io/apimachinery/pkg/runtime/schema"
 	watch "k8s.io/apimachinery/pkg/watch"
 	cache "k8s.io/client-go/tools/cache"
 )
@@ -48,36 +49,61 @@ type clusterScalingScheduleInformer struct {
 // Always prefer using an informer factory to get a shared informer instead of getting an independent
 // one. This reduces memory footprint and number of connections to the server.
 func NewClusterScalingScheduleInformer(client versioned.Interface, resyncPeriod time.Duration, indexers cache.Indexers) cache.SharedIndexInformer {
-	return NewFilteredClusterScalingScheduleInformer(client, resyncPeriod, indexers, nil)
+	return NewClusterScalingScheduleInformerWithOptions(client, internalinterfaces.InformerOptions{ResyncPeriod: resyncPeriod, Indexers: indexers})
 }
 
 // NewFilteredClusterScalingScheduleInformer constructs a new informer for ClusterScalingSchedule type.
 // Always prefer using an informer factory to get a shared informer instead of getting an independent
 // one. This reduces memory footprint and number of connections to the server.
 func NewFilteredClusterScalingScheduleInformer(client versioned.Interface, resyncPeriod time.Duration, indexers cache.Indexers, tweakListOptions internalinterfaces.TweakListOptionsFunc) cache.SharedIndexInformer {
-	return cache.NewSharedIndexInformer(
-		&cache.ListWatch{
-			ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
+	return NewClusterScalingScheduleInformerWithOptions(client, internalinterfaces.InformerOptions{ResyncPeriod: resyncPeriod, Indexers: indexers, TweakListOptions: tweakListOptions})
+}
+
+// NewClusterScalingScheduleInformerWithOptions constructs a new informer for ClusterScalingSchedule type with additional options.
+// Always prefer using an informer factory to get a shared informer instead of getting an independent
+// one. This reduces memory footprint and number of connections to the server.
+func NewClusterScalingScheduleInformerWithOptions(client versioned.Interface, options internalinterfaces.InformerOptions) cache.SharedIndexInformer {
+	gvr := schema.GroupVersionResource{Group: "zalando.org", Version: "v1", Resource: "clusterscalingschedules"}
+	identifier := options.InformerName.WithResource(gvr)
+	tweakListOptions := options.TweakListOptions
+	return cache.NewSharedIndexInformerWithOptions(
+		cache.ToListWatcherWithWatchListSemantics(&cache.ListWatch{
+			ListFunc: func(opts metav1.ListOptions) (runtime.Object, error) {
 				if tweakListOptions != nil {
-					tweakListOptions(&options)
+					tweakListOptions(&opts)
 				}
-				return client.ZalandoV1().ClusterScalingSchedules().List(context.TODO(), options)
+				return client.ZalandoV1().ClusterScalingSchedules().List(context.Background(), opts)
 			},
-			WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
+			WatchFunc: func(opts metav1.ListOptions) (watch.Interface, error) {
 				if tweakListOptions != nil {
-					tweakListOptions(&options)
+					tweakListOptions(&opts)
 				}
-				return client.ZalandoV1().ClusterScalingSchedules().Watch(context.TODO(), options)
+				return client.ZalandoV1().ClusterScalingSchedules().Watch(context.Background(), opts)
 			},
-		},
+			ListWithContextFunc: func(ctx context.Context, opts metav1.ListOptions) (runtime.Object, error) {
+				if tweakListOptions != nil {
+					tweakListOptions(&opts)
+				}
+				return client.ZalandoV1().ClusterScalingSchedules().List(ctx, opts)
+			},
+			WatchFuncWithContext: func(ctx context.Context, opts metav1.ListOptions) (watch.Interface, error) {
+				if tweakListOptions != nil {
+					tweakListOptions(&opts)
+				}
+				return client.ZalandoV1().ClusterScalingSchedules().Watch(ctx, opts)
+			},
+		}, client),
 		&apiszalandoorgv1.ClusterScalingSchedule{},
-		resyncPeriod,
-		indexers,
+		cache.SharedIndexInformerOptions{
+			ResyncPeriod: options.ResyncPeriod,
+			Indexers:     options.Indexers,
+			Identifier:   identifier,
+		},
 	)
 }
 
 func (f *clusterScalingScheduleInformer) defaultInformer(client versioned.Interface, resyncPeriod time.Duration) cache.SharedIndexInformer {
-	return NewFilteredClusterScalingScheduleInformer(client, resyncPeriod, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc}, f.tweakListOptions)
+	return NewClusterScalingScheduleInformerWithOptions(client, internalinterfaces.InformerOptions{ResyncPeriod: resyncPeriod, Indexers: cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc}, InformerName: f.factory.InformerName(), TweakListOptions: f.tweakListOptions})
 }
 
 func (f *clusterScalingScheduleInformer) Informer() cache.SharedIndexInformer {

pkg/client/informers/externalversions/zalando.org/v1/scalingschedule.go

@@ -28,6 +28,7 @@ import (
 	zalandoorgv1 "github.com/zalando-incubator/kube-metrics-adapter/pkg/client/listers/zalando.org/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	runtime "k8s.io/apimachinery/pkg/runtime"
+	schema "k8s.io/apimachinery/pkg/runtime/schema"
 	watch "k8s.io/apimachinery/pkg/watch"
 	cache "k8s.io/client-go/tools/cache"
 )
@@ -49,36 +50,61 @@ type scalingScheduleInformer struct {
 // Always prefer using an informer factory to get a shared informer instead of getting an independent
 // one. This reduces memory footprint and number of connections to the server.
 func NewScalingScheduleInformer(client versioned.Interface, namespace string, resyncPeriod time.Duration, indexers cache.Indexers) cache.SharedIndexInformer {
-	return NewFilteredScalingScheduleInformer(client, namespace, resyncPeriod, indexers, nil)
+	return NewScalingScheduleInformerWithOptions(client, namespace, internalinterfaces.InformerOptions{ResyncPeriod: resyncPeriod, Indexers: indexers})
 }
 
 // NewFilteredScalingScheduleInformer constructs a new informer for ScalingSchedule type.
 // Always prefer using an informer factory to get a shared informer instead of getting an independent
 // one. This reduces memory footprint and number of connections to the server.
 func NewFilteredScalingScheduleInformer(client versioned.Interface, namespace string, resyncPeriod time.Duration, indexers cache.Indexers, tweakListOptions internalinterfaces.TweakListOptionsFunc) cache.SharedIndexInformer {
-	return cache.NewSharedIndexInformer(
-		&cache.ListWatch{
-			ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
+	return NewScalingScheduleInformerWithOptions(client, namespace, internalinterfaces.InformerOptions{ResyncPeriod: resyncPeriod, Indexers: indexers, TweakListOptions: tweakListOptions})
+}
+
+// NewScalingScheduleInformerWithOptions constructs a new informer for ScalingSchedule type with additional options.
+// Always prefer using an informer factory to get a shared informer instead of getting an independent
+// one. This reduces memory footprint and number of connections to the server.
+func NewScalingScheduleInformerWithOptions(client versioned.Interface, namespace string, options internalinterfaces.InformerOptions) cache.SharedIndexInformer {
+	gvr := schema.GroupVersionResource{Group: "zalando.org", Version: "v1", Resource: "scalingschedules"}
+	identifier := options.InformerName.WithResource(gvr)
+	tweakListOptions := options.TweakListOptions
+	return cache.NewSharedIndexInformerWithOptions(
+		cache.ToListWatcherWithWatchListSemantics(&cache.ListWatch{
+			ListFunc: func(opts metav1.ListOptions) (runtime.Object, error) {
 				if tweakListOptions != nil {
-					tweakListOptions(&options)
+					tweakListOptions(&opts)
 				}
-				return client.ZalandoV1().ScalingSchedules(namespace).List(context.TODO(), options)
+				return client.ZalandoV1().ScalingSchedules(namespace).List(context.Background(), opts)
 			},
-			WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
+			WatchFunc: func(opts metav1.ListOptions) (watch.Interface, error) {
 				if tweakListOptions != nil {
-					tweakListOptions(&options)
+					tweakListOptions(&opts)
 				}
-				return client.ZalandoV1().ScalingSchedules(namespace).Watch(context.TODO(), options)
+				return client.ZalandoV1().ScalingSchedules(namespace).Watch(context.Background(), opts)
 			},
-		},
+			ListWithContextFunc: func(ctx context.Context, opts metav1.ListOptions) (runtime.Object, error) {
+				if tweakListOptions != nil {
+					tweakListOptions(&opts)
+				}
+				return client.ZalandoV1().ScalingSchedules(namespace).List(ctx, opts)
+			},
+			WatchFuncWithContext: func(ctx context.Context, opts metav1.ListOptions) (watch.Interface, error) {
+				if tweakListOptions != nil {
+					tweakListOptions(&opts)
+				}
+				return client.ZalandoV1().ScalingSchedules(namespace).Watch(ctx, opts)
+			},
+		}, client),
 		&apiszalandoorgv1.ScalingSchedule{},
-		resyncPeriod,
-		indexers,
+		cache.SharedIndexInformerOptions{
+			ResyncPeriod: options.ResyncPeriod,
+			Indexers:     options.Indexers,
+			Identifier:   identifier,
+		},
 	)
 }
 
 func (f *scalingScheduleInformer) defaultInformer(client versioned.Interface, resyncPeriod time.Duration) cache.SharedIndexInformer {
-	return NewFilteredScalingScheduleInformer(client, f.namespace, resyncPeriod, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc}, f.tweakListOptions)
+	return NewScalingScheduleInformerWithOptions(client, f.namespace, internalinterfaces.InformerOptions{ResyncPeriod: resyncPeriod, Indexers: cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc}, InformerName: f.factory.InformerName(), TweakListOptions: f.tweakListOptions})
 }
 
 func (f *scalingScheduleInformer) Informer() cache.SharedIndexInformer {

pkg/collector/collector.go

@@ -3,6 +3,7 @@ package collector
 import (
 	"context"
 	"fmt"
+	"strings"
 	"time"
 
 	log "github.com/sirupsen/logrus"
@@ -182,6 +183,25 @@ type MetricTypeName struct {
 	Metric autoscalingv2.MetricIdentifier
 }
 
+func (m MetricTypeName) String() string {
+	str := fmt.Sprintf("%s/%s", m.Type, m.Metric.Name)
+	if m.Metric.Selector != nil && len(m.Metric.Selector.MatchLabels) > 0 {
+		str += " " + mapToString(m.Metric.Selector.MatchLabels)
+	}
+	return str
+}
+
+func mapToString(m map[string]string) string {
+	str := "{"
+	keyVals := make([]string, 0, len(m))
+	for k, v := range m {
+		keyVals = append(keyVals, fmt.Sprintf("%s=%s", k, v))
+	}
+	str += strings.Join(keyVals, ",")
+	str += "}"
+	return str
+}
+
 type CollectedMetric struct {
 	Type      autoscalingv2.MetricSourceType
 	Namespace string