feat: add metrics-adapter component to support centralized hpa

Makefile

@@ -17,7 +17,8 @@ TARGETS := karmada-aggregated-apiserver \
 			karmada-scheduler-estimator \
 			karmada-interpreter-webhook-example \
 			karmada-search \
-			karmada-operator
+			karmada-operator \
+			karmada-metrics-adapter
 
 CTL_TARGETS := karmadactl kubectl-karmada
 
@@ -122,6 +123,7 @@ endif
 	docker push ${REGISTRY}/karmada-aggregated-apiserver:${VERSION}
 	docker push ${REGISTRY}/karmada-search:${VERSION}
 	docker push ${REGISTRY}/karmada-operator:${VERSION}
+	docker push ${REGISTRY}/karmada-metrics-adapter:${VERSION}
 
 # Build and package binary
 #

api/openapi-spec/swagger.json

@@ -10,7 +10,7 @@
     "version": "unversioned"
   },
   "paths": {
-    "/apis/": {
+    "/apis": {
       "get": {
         "description": "get available API versions",
         "consumes": [
@@ -40,7 +40,7 @@
         }
       }
     },
-    "/apis/cluster.karmada.io/": {
+    "/apis/cluster.karmada.io": {
       "get": {
         "description": "get information of a group",
         "consumes": [
@@ -70,7 +70,7 @@
         }
       }
     },
-    "/apis/cluster.karmada.io/v1alpha1/": {
+    "/apis/cluster.karmada.io/v1alpha1": {
       "get": {
         "description": "get available resources",
         "consumes": [
@@ -1564,7 +1564,7 @@
         }
       ]
     },
-    "/apis/config.karmada.io/": {
+    "/apis/config.karmada.io": {
       "get": {
         "description": "get information of a group",
         "consumes": [
@@ -1594,7 +1594,7 @@
         }
       }
     },
-    "/apis/config.karmada.io/v1alpha1/": {
+    "/apis/config.karmada.io/v1alpha1": {
       "get": {
         "description": "get available resources",
         "consumes": [
@@ -2624,7 +2624,7 @@
         }
       ]
     },
-    "/apis/networking.karmada.io/": {
+    "/apis/networking.karmada.io": {
       "get": {
         "description": "get information of a group",
         "consumes": [
@@ -2654,7 +2654,7 @@
         }
       }
     },
-    "/apis/networking.karmada.io/v1alpha1/": {
+    "/apis/networking.karmada.io/v1alpha1": {
       "get": {
         "description": "get available resources",
         "consumes": [
@@ -3940,7 +3940,7 @@
         }
       ]
     },
-    "/apis/policy.karmada.io/": {
+    "/apis/policy.karmada.io": {
       "get": {
         "description": "get information of a group",
         "consumes": [
@@ -3970,7 +3970,7 @@
         }
       }
     },
-    "/apis/policy.karmada.io/v1alpha1/": {
+    "/apis/policy.karmada.io/v1alpha1": {
       "get": {
         "description": "get available resources",
         "consumes": [
@@ -9768,7 +9768,7 @@
         }
       ]
     },
-    "/apis/search.karmada.io/": {
+    "/apis/search.karmada.io": {
       "get": {
         "description": "get information of a group",
         "consumes": [
@@ -9798,7 +9798,7 @@
         }
       }
     },
-    "/apis/search.karmada.io/v1alpha1/": {
+    "/apis/search.karmada.io/v1alpha1": {
       "get": {
         "description": "get available resources",
         "consumes": [
@@ -10828,7 +10828,7 @@
         }
       ]
     },
-    "/apis/work.karmada.io/": {
+    "/apis/work.karmada.io": {
       "get": {
         "description": "get information of a group",
         "consumes": [
@@ -10858,7 +10858,7 @@
         }
       }
     },
-    "/apis/work.karmada.io/v1alpha1/": {
+    "/apis/work.karmada.io/v1alpha1": {
       "get": {
         "description": "get available resources",
         "consumes": [
@@ -12144,7 +12144,7 @@
         }
       ]
     },
-    "/apis/work.karmada.io/v1alpha2/": {
+    "/apis/work.karmada.io/v1alpha2": {
       "get": {
         "description": "get available resources",
         "consumes": [
@@ -17081,8 +17081,13 @@
           "type": "string"
         },
         "pathType": {
-          "description": "PathType determines the interpretation of the Path matching. PathType can be one of the following values: * Exact: Matches the URL path exactly. * Prefix: Matches based on a URL path prefix split by '/'. Matching is\n  done on a path element by element basis. A path element refers is the\n  list of labels in the path split by the '/' separator. A request is a\n  match for path p if every p is an element-wise prefix of p of the\n  request path. Note that if the last element of the path is a substring\n  of the last element in request path, it is not a match (e.g. /foo/bar\n  matches /foo/bar/baz, but does not match /foo/barbaz).\n* ImplementationSpecific: Interpretation of the Path matching is up to\n  the IngressClass. Implementations can treat this as a separate PathType\n  or treat it identically to Prefix or Exact path types.\nImplementations are required to support all path types.",
-          "type": "string"
+          "description": "PathType determines the interpretation of the Path matching. PathType can be one of the following values: * Exact: Matches the URL path exactly. * Prefix: Matches based on a URL path prefix split by '/'. Matching is\n  done on a path element by element basis. A path element refers is the\n  list of labels in the path split by the '/' separator. A request is a\n  match for path p if every p is an element-wise prefix of p of the\n  request path. Note that if the last element of the path is a substring\n  of the last element in request path, it is not a match (e.g. /foo/bar\n  matches /foo/bar/baz, but does not match /foo/barbaz).\n* ImplementationSpecific: Interpretation of the Path matching is up to\n  the IngressClass. Implementations can treat this as a separate PathType\n  or treat it identically to Prefix or Exact path types.\nImplementations are required to support all path types.\n\nPossible enum values:\n - `\"Exact\"` matches the URL path exactly and with case sensitivity.\n - `\"ImplementationSpecific\"` matching is up to the IngressClass. Implementations can treat this as a separate PathType or treat it identically to Prefix or Exact path types.\n - `\"Prefix\"` matches based on a URL path prefix split by '/'. Matching is case sensitive and done on a path element by element basis. A path element refers to the list of labels in the path split by the '/' separator. A request is a match for path p if every p is an element-wise prefix of p of the request path. Note that if the last element of the path is a substring of the last element in request path, it is not a match (e.g. /foo/bar matches /foo/bar/baz, but does not match /foo/barbaz). If multiple matching paths exist in an Ingress spec, the longest matching path is given priority. Examples: - /foo/bar does not match requests to /foo/barbaz - /foo/bar matches request to /foo/bar and /foo/bar/baz - /foo and /foo/ both match requests to /foo and /foo/. If both paths are present in an Ingress spec, the longest matching path (/foo/) is given priority.",
+          "type": "string",
+          "enum": [
+            "Exact",
+            "ImplementationSpecific",
+            "Prefix"
+          ]
         }
       }
     },

artifacts/deploy/karmada-metrics-adapter-apiservice.yaml

@@ -0,0 +1,25 @@
+apiVersion: apiregistration.k8s.io/v1
+kind: APIService
+metadata:
+  name: v1beta1.metrics.k8s.io
+  labels:
+    app: karmada-metrics-adapter
+    apiserver: "true"
+spec:
+  insecureSkipTLSVerify: true
+  group: metrics.k8s.io
+  groupPriorityMinimum: 2000
+  service:
+    name: karmada-metrics-adapter
+    namespace: karmada-system
+  version: v1beta1
+  versionPriority: 10
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: karmada-metrics-adapter
+  namespace: karmada-system
+spec:
+  type: ExternalName
+  externalName: karmada-metrics-adapter.karmada-system.svc.cluster.local

artifacts/deploy/karmada-metrics-adapter.yaml

@@ -0,0 +1,86 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: karmada-metrics-adapter
+  namespace: karmada-system
+  labels:
+    app: karmada-metrics-adapter
+    apiserver: "true"
+spec:
+  selector:
+    matchLabels:
+      app: karmada-metrics-adapter
+      apiserver: "true"
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: karmada-metrics-adapter
+        apiserver: "true"
+    spec:
+      automountServiceAccountToken: false
+      containers:
+        - name: karmada-metrics-adapter
+          image: docker.io/karmada/karmada-metrics-adapter:latest
+          imagePullPolicy: IfNotPresent
+          volumeMounts:
+            - name: karmada-certs
+              mountPath: /etc/karmada/pki
+              readOnly: true
+            - name: kubeconfig
+              subPath: kubeconfig
+              mountPath: /etc/kubeconfig
+          command:
+            - /bin/karmada-metrics-adapter
+            - --kubeconfig=/etc/kubeconfig
+            - --authentication-kubeconfig=/etc/kubeconfig
+            - --authorization-kubeconfig=/etc/kubeconfig
+            - --client-ca-file=/etc/karmada/pki/ca.crt
+            - --audit-log-path=-
+            - --audit-log-maxage=0
+            - --audit-log-maxbackup=0
+          readinessProbe:
+            httpGet:
+              path: /readyz
+              port: 443
+              scheme: HTTPS
+            initialDelaySeconds: 1
+            failureThreshold: 3
+            periodSeconds: 3
+            timeoutSeconds: 15
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: 443
+              scheme: HTTPS
+            initialDelaySeconds: 10
+            failureThreshold: 3
+            periodSeconds: 10
+            timeoutSeconds: 15
+          resources:
+            requests:
+              cpu: 100m
+      volumes:
+        - name: karmada-certs
+          secret:
+            secretName: karmada-cert-secret
+        - name: kubeconfig
+          secret:
+            secretName: kubeconfig
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: karmada-metrics-adapter
+  namespace: karmada-system
+  labels:
+    app: karmada-metrics-adapter
+    apiserver: "true"
+spec:
+  ports:
+    - port: 443
+      protocol: TCP
+      targetPort: 443
+  selector:
+    app: karmada-metrics-adapter

cmd/metrics-adapter/app/metrics-adapter.go

@@ -0,0 +1,62 @@
+package app
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/spf13/cobra"
+	cliflag "k8s.io/component-base/cli/flag"
+	"k8s.io/component-base/term"
+
+	"github.com/karmada-io/karmada/cmd/metrics-adapter/app/options"
+	"github.com/karmada-io/karmada/pkg/sharedcli"
+	"github.com/karmada-io/karmada/pkg/sharedcli/klogflag"
+	"github.com/karmada-io/karmada/pkg/version/sharedcommand"
+)
+
+// NewMetricsAdapterCommand creates a *cobra.Command object with default parameters
+func NewMetricsAdapterCommand(ctx context.Context) *cobra.Command {
+	opts := options.NewOptions()
+
+	cmd := &cobra.Command{
+		Use:  "karmada-metrics-adapter",
+		Long: `The karmada-metrics-adapter is a adapter to aggregate the metrics from member clusters.`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := opts.Complete(); err != nil {
+				return err
+			}
+			if err := opts.Validate(); err != nil {
+				return err
+			}
+			if err := opts.Run(ctx); err != nil {
+				return err
+			}
+			return nil
+		},
+		Args: func(cmd *cobra.Command, args []string) error {
+			for _, arg := range args {
+				if len(arg) > 0 {
+					return fmt.Errorf("%q does not take any arguments, got %q", cmd.CommandPath(), args)
+				}
+			}
+			return nil
+		},
+	}
+
+	fss := cliflag.NamedFlagSets{}
+
+	genericFlagSet := fss.FlagSet("generic")
+	opts.AddFlags(genericFlagSet)
+
+	// Set klog flags
+	logsFlagSet := fss.FlagSet("logs")
+	klogflag.Add(logsFlagSet)
+
+	cmd.AddCommand(sharedcommand.NewCmdVersion("karmada-metrics-adapter"))
+	cmd.Flags().AddFlagSet(genericFlagSet)
+	cmd.Flags().AddFlagSet(logsFlagSet)
+
+	cols, _, _ := term.TerminalSize(cmd.OutOrStdout())
+	sharedcli.SetUsageAndHelpFunc(cmd, fss, cols)
+	return cmd
+}