feat: support to get pod metrics in operator apiserver (#202)

cmd/operator/app/command.go

@@ -26,6 +26,7 @@ import (
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/klog/v2"
 	"k8s.io/klog/v2/klogr"
+	podmetricsv1beta1 "k8s.io/metrics/pkg/apis/metrics/v1beta1"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
@@ -47,10 +48,20 @@ var (
 )
 
 func init() {
+	// Add Kubernetes client-go scheme.
 	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
+
+	// Add Kubernetes API extensions.
+	utilruntime.Must(apiextensionsv1.AddToScheme(scheme))
+
+	// Add GreptimeDB CRD.
 	utilruntime.Must(v1alpha1.AddToScheme(scheme))
+
+	// Add prometheus-operator's CRDs for monitoring(PodMonitor and ServiceMonitor).
 	utilruntime.Must(monitoringv1.AddToScheme(scheme))
-	utilruntime.Must(apiextensionsv1.AddToScheme(scheme))
+
+	// Add [PodMetrics](https://github.com/kubernetes/metrics/blob/master/pkg/apis/metrics/v1beta1/types.go) for fetching PodMetrics from metrics-server.
+	utilruntime.Must(podmetricsv1beta1.AddToScheme(scheme))
 
 	// +kubebuilder:scaffold:scheme
 }
@@ -102,7 +113,8 @@ func NewOperatorCommand() *cobra.Command {
 
 			if o.EnableAPIServer {
 				server := apiserver.NewServer(mgr.GetClient(), &apiserver.Options{
-					Port: o.APIServerPort,
+					Port:             o.APIServerPort,
+					EnablePodMetrics: o.EnablePodMetrics,
 				})
 
 				go func() {

cmd/operator/app/options/options.go

@@ -30,14 +30,16 @@ type Options struct {
 	EnableLeaderElection bool
 	EnableAPIServer      bool
 	APIServerPort        int32
+	EnablePodMetrics     bool
 }
 
 func NewDefaultOptions() *Options {
 	return &Options{
-		MetricsAddr:     defaultMetricsAddr,
-		HealthProbeAddr: defaultHealthProbeAddr,
-		APIServerPort:   defaultAPIServerPort,
-		EnableAPIServer: false,
+		MetricsAddr:      defaultMetricsAddr,
+		HealthProbeAddr:  defaultHealthProbeAddr,
+		APIServerPort:    defaultAPIServerPort,
+		EnableAPIServer:  false,
+		EnablePodMetrics: false,
 	}
 }
 
@@ -47,4 +49,5 @@ func (o *Options) AddFlags(fs *pflag.FlagSet) {
 	fs.BoolVar(&o.EnableLeaderElection, "enable-leader-election", o.EnableLeaderElection, "Enable leader election for controller manager. Enabling this will ensure there is only one active controller manager.")
 	fs.BoolVar(&o.EnableAPIServer, "enable-apiserver", o.EnableAPIServer, "Enable API server for GreptimeDB operator.")
 	fs.Int32Var(&o.APIServerPort, "apiserver-port", o.APIServerPort, "The port the API server binds to.")
+	fs.BoolVar(&o.EnablePodMetrics, "enable-pod-metrics", o.EnablePodMetrics, "Enable fetching PodMetrics from metrics-server.")
 }

go.mod

@@ -17,11 +17,12 @@ require (
 	github.com/spf13/pflag v1.0.5
 	go.etcd.io/etcd/client/v3 v3.5.9
 	google.golang.org/grpc v1.56.3
-	k8s.io/api v0.28.3
+	k8s.io/api v0.28.13
 	k8s.io/apiextensions-apiserver v0.28.3
-	k8s.io/apimachinery v0.28.3
-	k8s.io/client-go v0.28.3
+	k8s.io/apimachinery v0.28.13
+	k8s.io/client-go v0.28.13
 	k8s.io/klog/v2 v2.100.1
+	k8s.io/metrics v0.28.13
 	k8s.io/utils v0.0.0-20230406110748-d93618cff8a2
 	sigs.k8s.io/controller-runtime v0.16.4
 	sigs.k8s.io/yaml v1.3.0
@@ -54,7 +55,7 @@ require (
 	github.com/goccy/go-json v0.10.2 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
-	github.com/golang/protobuf v1.5.3 // 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/pprof v0.0.0-20210720184732-4bb14d4b1be1 // indirect
@@ -95,7 +96,7 @@ require (
 	golang.org/x/term v0.20.0 // indirect
 	golang.org/x/text v0.15.0 // indirect
 	golang.org/x/time v0.3.0 // indirect
-	golang.org/x/tools v0.9.3 // indirect
+	golang.org/x/tools v0.16.1 // indirect
 	gomodules.xyz/jsonpatch/v2 v2.4.0 // indirect
 	google.golang.org/appengine v1.6.7 // indirect
 	google.golang.org/genproto v0.0.0-20230526161137-0005af68ea54 // indirect

go.sum

@@ -73,12 +73,10 @@ github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l
 github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
-github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
-github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
+github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
+github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/gnostic-models v0.6.8 h1:yo/ABAfM5IMRsS1VnXjTBvUb61tFIHozhlYvRgGre9I=
 github.com/google/gnostic-models v0.6.8/go.mod h1:5n7qKqH0f5wFt+aWF8CW6pZLLNOfYuF5OpfBSENuI8U=
-github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
@@ -218,8 +216,6 @@ golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHl
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/mod v0.10.0 h1:lFO9qtOdlre5W1jxS3r/4szv2/6iXxScdzjoBMXNhYk=
-golang.org/x/mod v0.10.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
@@ -236,8 +232,8 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
-golang.org/x/sync v0.2.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
+golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191204072324-ce4227a45e2e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -266,8 +262,8 @@ golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.0.0-20200619180055-7c47624df98f/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20210106214847-113979e3529a/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
-golang.org/x/tools v0.9.3 h1:Gn1I8+64MsuTb/HpH+LmQtNas23LhUVr3rYZ0eKuaMM=
-golang.org/x/tools v0.9.3/go.mod h1:owI94Op576fPu3cIGQeHs3joujW/2Oc6MtlxbF5dfNc=
+golang.org/x/tools v0.16.1 h1:TLyB3WofjdOEepBHAU20JdNC1Zbg87elYofWYAY5oZA=
+golang.org/x/tools v0.16.1/go.mod h1:kYVVN6I1mBNoB1OX+noeBjbRk4IUEPa7JJ+TJMEooJ0=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
@@ -284,8 +280,6 @@ google.golang.org/genproto/googleapis/rpc v0.0.0-20230525234030-28d5490b6b19 h1:
 google.golang.org/genproto/googleapis/rpc v0.0.0-20230525234030-28d5490b6b19/go.mod h1:66JfowdXAEgad5O9NnYcsNPLCPZJD++2L9X0PCMODrA=
 google.golang.org/grpc v1.56.3 h1:8I4C0Yq1EjstUzUJzpcRVbuYA2mODtEmpWiQoN/b2nc=
 google.golang.org/grpc v1.56.3/go.mod h1:I9bI3vqKfayGqPUAwGdOSu7kt6oIJLixfffKrpXqQ9s=
-google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
-google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
 google.golang.org/protobuf v1.34.1/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
@@ -303,20 +297,22 @@ gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C
 gopkg.in/yaml.v3 v3.0.0/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-k8s.io/api v0.28.3 h1:Gj1HtbSdB4P08C8rs9AR94MfSGpRhJgsS+GF9V26xMM=
-k8s.io/api v0.28.3/go.mod h1:MRCV/jr1dW87/qJnZ57U5Pak65LGmQVkKTzf3AtKFHc=
+k8s.io/api v0.28.13 h1:0Sw8MjdkmrJAF/uVv09HXSZ3cQauVyZHQWKt8hiiKo4=
+k8s.io/api v0.28.13/go.mod h1:7hlRF5wArzXf0qbRRT2TMtHRa5SHBEVJhA02JpTxj9Q=
 k8s.io/apiextensions-apiserver v0.28.3 h1:Od7DEnhXHnHPZG+W9I97/fSQkVpVPQx2diy+2EtmY08=
 k8s.io/apiextensions-apiserver v0.28.3/go.mod h1:NE1XJZ4On0hS11aWWJUTNkmVB03j9LM7gJSisbRt8Lc=
-k8s.io/apimachinery v0.28.3 h1:B1wYx8txOaCQG0HmYF6nbpU8dg6HvA06x5tEffvOe7A=
-k8s.io/apimachinery v0.28.3/go.mod h1:uQTKmIqs+rAYaq+DFaoD2X7pcjLOqbQX2AOiO0nIpb8=
-k8s.io/client-go v0.28.3 h1:2OqNb72ZuTZPKCl+4gTKvqao0AMOl9f3o2ijbAj3LI4=
-k8s.io/client-go v0.28.3/go.mod h1:LTykbBp9gsA7SwqirlCXBWtK0guzfhpoW4qSm7i9dxo=
+k8s.io/apimachinery v0.28.13 h1:0O2mk2i0Yi+xkron0lK//biI21F1eGXb4eXECLU5v7g=
+k8s.io/apimachinery v0.28.13/go.mod h1:zUG757HaKs6Dc3iGtKjzIpBfqTM4yiRsEe3/E7NX15o=
+k8s.io/client-go v0.28.13 h1:kHgFOxWwAsa8VxL6Oylo10V6euobub9Jo0wyEWrhrWk=
+k8s.io/client-go v0.28.13/go.mod h1:IudvInbWfd+6WLreEVnBnZJCGFaSROCFbny9jFTkk7g=
 k8s.io/component-base v0.28.3 h1:rDy68eHKxq/80RiMb2Ld/tbH8uAE75JdCqJyi6lXMzI=
 k8s.io/component-base v0.28.3/go.mod h1:fDJ6vpVNSk6cRo5wmDa6eKIG7UlIQkaFmZN2fYgIUD8=
 k8s.io/klog/v2 v2.100.1 h1:7WCHKK6K8fNhTqfBhISHQ97KrnJNFZMcQvKp7gP/tmg=
 k8s.io/klog/v2 v2.100.1/go.mod h1:y1WjHnz7Dj687irZUWR/WLkLc5N1YHtjLdmgWjndZn0=
 k8s.io/kube-openapi v0.0.0-20230717233707-2695361300d9 h1:LyMgNKD2P8Wn1iAwQU5OhxCKlKJy0sHc+PcDwFB24dQ=
 k8s.io/kube-openapi v0.0.0-20230717233707-2695361300d9/go.mod h1:wZK2AVp1uHCp4VamDVgBP2COHZjqD1T68Rf0CM3YjSM=
+k8s.io/metrics v0.28.13 h1:q3SbR/2b+drO1pFhQvNMWo9+VVzNkXx9zjn40RuQbXc=
+k8s.io/metrics v0.28.13/go.mod h1:UKcfHy+KvTkjrUL4mz0NS7Hb872Q/ponmJw3hQoGNa8=
 k8s.io/utils v0.0.0-20230406110748-d93618cff8a2 h1:qY1Ad8PODbnymg2pRbkyMT/ylpTrCM8P2RJ0yroCyIk=
 k8s.io/utils v0.0.0-20230406110748-d93618cff8a2/go.mod h1:OLgZIPagt7ERELqWJFomSt595RzquPNLL48iOWgYOg0=
 nullprogram.com/x/optparse v1.0.0/go.mod h1:KdyPE+Igbe0jQUrVfMqDMeJQIJZEuyV7pjYmp6pbG50=

pkg/apiserver/apiserver.go

@@ -24,6 +24,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/klog/v2"
+	podmetricsv1beta1 "k8s.io/metrics/pkg/apis/metrics/v1beta1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	greptimev1alpha1 "github.com/GreptimeTeam/greptimedb-operator/apis/v1alpha1"
@@ -40,13 +41,17 @@ const (
 type Server struct {
 	client.Client
 
-	port int32
+	port             int32
+	enablePodMetrics bool
 }
 
 // Options represents the options for the Server.
 type Options struct {
 	// Port is the port that the API service will listen on.
 	Port int32
+
+	// EnablePodMetrics indicates whether to enable fetching PodMetrics from metrics-server.
+	EnablePodMetrics bool
 }
 
 // GreptimeDBCluster represents a GreptimeDBCluster resource that is returned by the API.
@@ -97,8 +102,8 @@ type Pod struct {
 	// Node is the name of the node where the Pod is running.
 	Node string `json:"node"`
 
-	// Resource is the resource requirements of the Pod.
-	Resource corev1.ResourceRequirements `json:"resource,omitempty"`
+	// Resource is the resources of all containers in the Pod.
+	Resources []*Resource `json:"resources,omitempty"`
 
 	// Status is the status of the Pod.
 	Status string `json:"status"`
@@ -107,6 +112,21 @@ type Pod struct {
 	StartTime *metav1.Time `json:"startTime,omitempty"`
 }
 
+// Resource represents the resource of a container.
+type Resource struct {
+	// Name is the name of the container.
+	Name string `json:"name"`
+
+	// Request is the resource request of the container.
+	Request corev1.ResourceList `json:"request,omitempty"`
+
+	// Limit is the resource limit of the container.
+	Limit corev1.ResourceList `json:"limit,omitempty"`
+
+	// Usage is the resource usage of the container.
+	Usage corev1.ResourceList `json:"usage,omitempty"`
+}
+
 // Response represents a response returned by the API.
 type Response struct {
 	// Success indicates whether the request was successful.
@@ -125,8 +145,9 @@ type Response struct {
 // NewServer creates a new Server with the given client and options.
 func NewServer(client client.Client, opts *Options) *Server {
 	return &Server{
-		Client: client,
-		port:   opts.Port,
+		Client:           client,
+		port:             opts.Port,
+		enablePodMetrics: opts.EnablePodMetrics,
 	}
 }
 
@@ -288,46 +309,89 @@ func (s *Server) getTopology(ctx context.Context, namespace, name string) (*Grep
 }
 
 func (s *Server) getPods(ctx context.Context, namespace, name string, kind greptimev1alpha1.ComponentKind, topology *GreptimeDBClusterTopology) error {
-	var pods corev1.PodList
-	if err := s.List(ctx, &pods, client.InNamespace(namespace),
+	var internalPods corev1.PodList
+	if err := s.List(ctx, &internalPods, client.InNamespace(namespace),
 		client.MatchingLabels{constant.GreptimeDBComponentName: common.ResourceName(name, kind)}); err != nil {
 		return err
 	}
 
+	var metrics []*podmetricsv1beta1.PodMetrics
+	if s.enablePodMetrics {
+		for _, pod := range internalPods.Items {
+			podMetrics, err := s.getPodMetrics(ctx, namespace, pod.Name)
+			if err != nil {
+				return err
+			}
+			metrics = append(metrics, podMetrics)
+		}
+
+		if len(metrics) != len(internalPods.Items) {
+			return fmt.Errorf("the number of metrics is not equal to the number of pods")
+		}
+	}
+
+	var pods []*Pod
+	// zip internalPods and metrics.
+	for i, pod := range internalPods.Items {
+		if s.enablePodMetrics {
+			pods = append(pods, s.buildPod(&pod, metrics[i]))
+		} else {
+			pods = append(pods, s.buildPod(&pod, nil))
+		}
+	}
+
 	switch kind {
 	case greptimev1alpha1.MetaComponentKind:
-		for _, pod := range pods.Items {
-			topology.Meta = append(topology.Meta, s.convertToPod(&pod))
-		}
+		topology.Meta = pods
 	case greptimev1alpha1.DatanodeComponentKind:
-		for _, pod := range pods.Items {
-			topology.Datanode = append(topology.Datanode, s.convertToPod(&pod))
-		}
+		topology.Datanode = pods
 	case greptimev1alpha1.FrontendComponentKind:
-		for _, pod := range pods.Items {
-			topology.Frontend = append(topology.Frontend, s.convertToPod(&pod))
-		}
+		topology.Frontend = pods
 	case greptimev1alpha1.FlownodeComponentKind:
-		for _, pod := range pods.Items {
-			topology.Flownode = append(topology.Flownode, s.convertToPod(&pod))
-		}
+		topology.Flownode = pods
 	}
 
 	return nil
 }
 
-func (s *Server) convertToPod(pod *corev1.Pod) *Pod {
-	var resources corev1.ResourceRequirements
-	if len(pod.Spec.Containers) > constant.MainContainerIndex {
-		resources = pod.Spec.Containers[constant.MainContainerIndex].Resources
+func (s *Server) buildPod(internalPod *corev1.Pod, podMetrics *podmetricsv1beta1.PodMetrics) *Pod {
+	pod := &Pod{
+		Name:      internalPod.Name,
+		Namespace: internalPod.Namespace,
+		IP:        internalPod.Status.PodIP,
+		Status:    string(internalPod.Status.Phase),
+		Node:      internalPod.Spec.NodeName,
+	}
+
+	var resources []*Resource
+
+	for _, container := range internalPod.Spec.Containers {
+		resources = append(resources, &Resource{
+			Name:    container.Name,
+			Request: container.Resources.Requests,
+			Limit:   container.Resources.Limits,
+		})
 	}
-	return &Pod{
-		Name:      pod.Name,
-		Namespace: pod.Namespace,
-		IP:        pod.Status.PodIP,
-		Status:    string(pod.Status.Phase),
-		Node:      pod.Spec.NodeName,
-		Resource:  resources,
-		StartTime: pod.Status.StartTime,
+
+	if s.enablePodMetrics && podMetrics != nil {
+		for _, container := range podMetrics.Containers {
+			for _, resource := range resources {
+				if resource.Name == container.Name {
+					resource.Usage = container.Usage
+				}
+			}
+		}
+	}
+
+	pod.Resources = resources
+
+	return pod
+}
+
+func (s *Server) getPodMetrics(ctx context.Context, namespace, name string) (*podmetricsv1beta1.PodMetrics, error) {
+	var podMetrics podmetricsv1beta1.PodMetrics
+	if err := s.Get(ctx, client.ObjectKey{Namespace: namespace, Name: name}, &podMetrics); err != nil {
+		return nil, err
 	}
+	return &podMetrics, nil
 }