Refactor supervisor listener startup and add metrics

pkg/agent/config/config.go

@@ -524,12 +524,14 @@ func get(ctx context.Context, envInfo *cmds.Agent, proxy proxy.Proxy) (*config.N
 		SELinux:                  envInfo.EnableSELinux,
 		ContainerRuntimeEndpoint: envInfo.ContainerRuntimeEndpoint,
 		ImageServiceEndpoint:     envInfo.ImageServiceEndpoint,
+		EnablePProf:              envInfo.EnablePProf,
 		EmbeddedRegistry:         controlConfig.EmbeddedRegistry,
 		FlannelBackend:           controlConfig.FlannelBackend,
 		FlannelIPv6Masq:          controlConfig.FlannelIPv6Masq,
 		FlannelExternalIP:        controlConfig.FlannelExternalIP,
 		EgressSelectorMode:       controlConfig.EgressSelectorMode,
 		ServerHTTPSPort:          controlConfig.HTTPSPort,
+		SupervisorMetrics:        controlConfig.SupervisorMetrics,
 		Token:                    info.String(),
 	}
 	nodeConfig.FlannelIface = flannelIface
@@ -592,13 +594,18 @@ func get(ctx context.Context, envInfo *cmds.Agent, proxy proxy.Proxy) (*config.N
 	nodeConfig.Containerd.Template = filepath.Join(envInfo.DataDir, "agent", "etc", "containerd", "config.toml.tmpl")
 	nodeConfig.Certificate = servingCert
 
-	nodeConfig.AgentConfig.NodeIPs = nodeIPs
-	listenAddress, _, _, err := util.GetDefaultAddresses(nodeIPs[0])
-	if err != nil {
-		return nil, errors.Wrap(err, "cannot configure IPv4/IPv6 node-ip")
+	if envInfo.BindAddress != "" {
+		nodeConfig.AgentConfig.ListenAddress = envInfo.BindAddress
+	} else {
+		listenAddress, _, _, err := util.GetDefaultAddresses(nodeIPs[0])
+		if err != nil {
+			return nil, errors.Wrap(err, "cannot configure IPv4/IPv6 node-ip")
+		}
+		nodeConfig.AgentConfig.ListenAddress = listenAddress
 	}
+
 	nodeConfig.AgentConfig.NodeIP = nodeIPs[0].String()
-	nodeConfig.AgentConfig.ListenAddress = listenAddress
+	nodeConfig.AgentConfig.NodeIPs = nodeIPs
 	nodeConfig.AgentConfig.NodeExternalIPs = nodeExternalIPs
 
 	// if configured, set NodeExternalIP to the first IPv4 address, for legacy clients
@@ -689,6 +696,8 @@ func get(ctx context.Context, envInfo *cmds.Agent, proxy proxy.Proxy) (*config.N
 	nodeConfig.AgentConfig.ImageCredProvConfig = envInfo.ImageCredProvConfig
 	nodeConfig.AgentConfig.DisableCCM = controlConfig.DisableCCM
 	nodeConfig.AgentConfig.DisableNPC = controlConfig.DisableNPC
+	nodeConfig.AgentConfig.MinTLSVersion = controlConfig.MinTLSVersion
+	nodeConfig.AgentConfig.CipherSuites = controlConfig.CipherSuites
 	nodeConfig.AgentConfig.Rootless = envInfo.Rootless
 	nodeConfig.AgentConfig.PodManifests = filepath.Join(envInfo.DataDir, "agent", DefaultPodManifestPath)
 	nodeConfig.AgentConfig.ProtectKernelDefaults = envInfo.ProtectKernelDefaults

pkg/agent/https/https.go

+package https
+
+import (
+	"context"
+	"net/http"
+	"strconv"
+	"sync"
+
+	"github.com/gorilla/mux"
+	"github.com/k3s-io/k3s/pkg/daemons/config"
+	"github.com/k3s-io/k3s/pkg/generated/clientset/versioned/scheme"
+	"github.com/k3s-io/k3s/pkg/util"
+	"github.com/k3s-io/k3s/pkg/version"
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+	"k8s.io/apiserver/pkg/authorization/authorizer"
+	genericapifilters "k8s.io/apiserver/pkg/endpoints/filters"
+	apirequest "k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/server"
+	"k8s.io/apiserver/pkg/server/options"
+)
+
+// RouterFunc provides a hook for components to register additional routes to a request router
+type RouterFunc func(ctx context.Context, nodeConfig *config.Node) (*mux.Router, error)
+
+var once sync.Once
+var router *mux.Router
+var err error
+
+// Start returns a router with authn/authz filters applied.
+// The first time it is called, the router is created and a new HTTPS listener is started if the handler is nil.
+// Subsequent calls will return the same router.
+func Start(ctx context.Context, nodeConfig *config.Node, runtime *config.ControlRuntime) (*mux.Router, error) {
+	once.Do(func() {
+		router = mux.NewRouter().SkipClean(true)
+		config := server.Config{}
+
+		if runtime == nil {
+			// If we do not have an existing handler, set up a new listener
+			tcp, lerr := util.ListenWithLoopback(ctx, nodeConfig.AgentConfig.ListenAddress, strconv.Itoa(nodeConfig.ServerHTTPSPort))
+			if lerr != nil {
+				err = lerr
+				return
+			}
+
+			serving := options.NewSecureServingOptions()
+			serving.Listener = tcp
+			serving.CipherSuites = nodeConfig.AgentConfig.CipherSuites
+			serving.MinTLSVersion = nodeConfig.AgentConfig.MinTLSVersion
+			serving.ServerCert = options.GeneratableKeyCert{
+				CertKey: options.CertKey{
+					CertFile: nodeConfig.AgentConfig.ServingKubeletCert,
+					KeyFile:  nodeConfig.AgentConfig.ServingKubeletKey,
+				},
+			}
+			if aerr := serving.ApplyTo(&config.SecureServing); aerr != nil {
+				err = aerr
+				return
+			}
+		} else {
+			// If we have an existing handler, wrap it
+			router.NotFoundHandler = runtime.Handler
+			runtime.Handler = router
+		}
+
+		authn := options.NewDelegatingAuthenticationOptions()
+		authn.DisableAnonymous = true
+		authn.SkipInClusterLookup = true
+		authn.ClientCert = options.ClientCertAuthenticationOptions{
+			ClientCA: nodeConfig.AgentConfig.ClientCA,
+		}
+		authn.RemoteKubeConfigFile = nodeConfig.AgentConfig.KubeConfigKubelet
+		if applyErr := authn.ApplyTo(&config.Authentication, config.SecureServing, nil); applyErr != nil {
+			err = applyErr
+			return
+		}
+
+		authz := options.NewDelegatingAuthorizationOptions()
+		authz.AlwaysAllowPaths = []string{"/v2", "/debug/pprof", "/v1-" + version.Program + "/p2p"}
+		authz.RemoteKubeConfigFile = nodeConfig.AgentConfig.KubeConfigKubelet
+		if applyErr := authz.ApplyTo(&config.Authorization); applyErr != nil {
+			err = applyErr
+			return
+		}
+
+		router.Use(filterChain(config.Authentication.Authenticator, config.Authorization.Authorizer))
+
+		if config.SecureServing != nil {
+			_, _, err = config.SecureServing.Serve(router, 0, ctx.Done())
+		}
+	})
+
+	return router, err
+}
+
+// filterChain runs the kubernetes authn/authz filter chain using the mux middleware API
+func filterChain(authn authenticator.Request, authz authorizer.Authorizer) mux.MiddlewareFunc {
+	return func(handler http.Handler) http.Handler {
+		requestInfoResolver := &apirequest.RequestInfoFactory{}
+		failedHandler := genericapifilters.Unauthorized(scheme.Codecs)
+		handler = genericapifilters.WithAuthorization(handler, authz, scheme.Codecs)
+		handler = genericapifilters.WithAuthentication(handler, authn, failedHandler, nil, nil)
+		handler = genericapifilters.WithRequestInfo(handler, requestInfoResolver)
+		handler = genericapifilters.WithCacheControl(handler)
+		return handler
+	}
+}

pkg/agent/netpol/netpol.go

@@ -19,25 +19,25 @@ import (
 
 	"github.com/cloudnativelabs/kube-router/v2/pkg/controllers/netpol"
 	"github.com/cloudnativelabs/kube-router/v2/pkg/healthcheck"
-	"github.com/cloudnativelabs/kube-router/v2/pkg/metrics"
+	krmetrics "github.com/cloudnativelabs/kube-router/v2/pkg/metrics"
 	"github.com/cloudnativelabs/kube-router/v2/pkg/options"
 	"github.com/cloudnativelabs/kube-router/v2/pkg/utils"
 	"github.com/cloudnativelabs/kube-router/v2/pkg/version"
 	"github.com/coreos/go-iptables/iptables"
 	"github.com/k3s-io/k3s/pkg/daemons/config"
+	"github.com/k3s-io/k3s/pkg/metrics"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	v1core "k8s.io/api/core/v1"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/clientcmd"
-	"k8s.io/component-base/metrics/legacyregistry"
 )
 
 func init() {
 	// ensure that kube-router exposes metrics through the same registry used by Kubernetes components
-	metrics.DefaultRegisterer = legacyregistry.Registerer()
-	metrics.DefaultGatherer = legacyregistry.DefaultGatherer
+	krmetrics.DefaultRegisterer = metrics.DefaultRegisterer
+	krmetrics.DefaultGatherer = metrics.DefaultGatherer
 }
 
 // Run creates and starts a new instance of the kube-router network policy controller
@@ -156,7 +156,7 @@ func Run(ctx context.Context, nodeConfig *config.Node) error {
 	}
 
 	// Start kube-router metrics controller to avoid complaints about metrics heartbeat missing
-	mc, err := metrics.NewMetricsController(krConfig)
+	mc, err := krmetrics.NewMetricsController(krConfig)
 	if err != nil {
 		return nil
 	}
@@ -188,13 +188,13 @@ func Run(ctx context.Context, nodeConfig *config.Node) error {
 }
 
 // metricsRunCheck is a stub version of mc.Run() that doesn't start up a dedicated http server.
-func metricsRunCheck(mc *metrics.Controller, healthChan chan<- *healthcheck.ControllerHeartbeat, stopCh <-chan struct{}, wg *sync.WaitGroup) {
+func metricsRunCheck(mc *krmetrics.Controller, healthChan chan<- *healthcheck.ControllerHeartbeat, stopCh <-chan struct{}, wg *sync.WaitGroup) {
 	t := time.NewTicker(3 * time.Second)
 	defer wg.Done()
 
 	// register metrics for this controller
-	metrics.BuildInfo.WithLabelValues(runtime.Version(), version.Version).Set(1)
-	metrics.DefaultRegisterer.MustRegister(metrics.BuildInfo)
+	krmetrics.BuildInfo.WithLabelValues(runtime.Version(), version.Version).Set(1)
+	krmetrics.DefaultRegisterer.MustRegister(krmetrics.BuildInfo)
 
 	for {
 		healthcheck.SendHeartBeat(healthChan, "MC")

pkg/agent/run.go

@@ -27,7 +27,9 @@ import (
 	"github.com/k3s-io/k3s/pkg/daemons/agent"
 	daemonconfig "github.com/k3s-io/k3s/pkg/daemons/config"
 	"github.com/k3s-io/k3s/pkg/daemons/executor"
+	"github.com/k3s-io/k3s/pkg/metrics"
 	"github.com/k3s-io/k3s/pkg/nodeconfig"
+	"github.com/k3s-io/k3s/pkg/profile"
 	"github.com/k3s-io/k3s/pkg/rootless"
 	"github.com/k3s-io/k3s/pkg/spegel"
 	"github.com/k3s-io/k3s/pkg/util"
@@ -113,6 +115,18 @@ func run(ctx context.Context, cfg cmds.Agent, proxy proxy.Proxy) error {
 		}
 	}
 
+	if nodeConfig.SupervisorMetrics {
+		if err := metrics.DefaultMetrics.Start(ctx, nodeConfig); err != nil {
+			return errors.Wrap(err, "failed to serve metrics")
+		}
+	}
+
+	if nodeConfig.EnablePProf {
+		if err := profile.DefaultProfiler.Start(ctx, nodeConfig); err != nil {
+			return errors.Wrap(err, "failed to serve pprof")
+		}
+	}
+
 	if err := setupCriCtlConfig(cfg, nodeConfig); err != nil {
 		return err
 	}

pkg/certmonitor/certmonitor.go

@@ -11,6 +11,7 @@ import (
 
 	daemonconfig "github.com/k3s-io/k3s/pkg/daemons/config"
 	"github.com/k3s-io/k3s/pkg/daemons/control/deps"
+	"github.com/k3s-io/k3s/pkg/metrics"
 	"github.com/k3s-io/k3s/pkg/util"
 	"github.com/k3s-io/k3s/pkg/util/services"
 	"github.com/k3s-io/k3s/pkg/version"
@@ -22,18 +23,9 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/wait"
-	"k8s.io/component-base/metrics/legacyregistry"
 )
 
 var (
-	// DefaultRegisterer and DefaultGatherer are the implementations of the
-	// prometheus Registerer and Gatherer interfaces that all metrics operations
-	// will use. They are variables so that packages that embed this library can
-	// replace them at runtime, instead of having to pass around specific
-	// registries.
-	DefaultRegisterer = legacyregistry.Registerer()
-	DefaultGatherer   = legacyregistry.DefaultGatherer
-
 	// Check certificates twice an hour. Kubernetes events have a TTL of 1 hour by default,
 	// so similar events should be aggregated and refreshed by the event recorder as long
 	// as they are created within the TTL period.
@@ -50,7 +42,7 @@ var (
 // Setup starts the certificate expiration monitor
 func Setup(ctx context.Context, nodeConfig *daemonconfig.Node, dataDir string) error {
 	logrus.Debugf("Starting %s with monitoring period %s", controllerName, certCheckInterval)
-	DefaultRegisterer.MustRegister(certificateExpirationSeconds)
+	metrics.DefaultRegisterer.MustRegister(certificateExpirationSeconds)
 
 	client, err := util.GetClientSet(nodeConfig.AgentConfig.KubeConfigKubelet)
 	if err != nil {

pkg/cli/agent/agent.go

 package agent
 
 import (
+	"context"
 	"crypto/tls"
-	"errors"
 	"fmt"
-	"net/http"
 	"os"
 	"path/filepath"
 	"runtime"
 
 	"github.com/gorilla/mux"
 	"github.com/k3s-io/k3s/pkg/agent"
-	"github.com/k3s-io/k3s/pkg/authenticator"
+	"github.com/k3s-io/k3s/pkg/agent/https"
 	"github.com/k3s-io/k3s/pkg/cli/cmds"
+	"github.com/k3s-io/k3s/pkg/daemons/config"
 	"github.com/k3s-io/k3s/pkg/datadir"
+	k3smetrics "github.com/k3s-io/k3s/pkg/metrics"
 	"github.com/k3s-io/k3s/pkg/proctitle"
+	"github.com/k3s-io/k3s/pkg/profile"
 	"github.com/k3s-io/k3s/pkg/spegel"
 	"github.com/k3s-io/k3s/pkg/util"
 	"github.com/k3s-io/k3s/pkg/version"
@@ -22,7 +24,6 @@ import (
 	"github.com/rancher/wrangler/v3/pkg/signals"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
-	apiauth "k8s.io/apiserver/pkg/authentication/authenticator"
 )
 
 func Run(ctx *cli.Context) error {
@@ -108,33 +109,22 @@ func Run(ctx *cli.Context) error {
 	// Until the agent is run and retrieves config from the server, we won't know
 	// if the embedded registry is enabled. If it is not enabled, these are not
 	// used as the registry is never started.
-	conf := spegel.DefaultRegistry
-	conf.Bootstrapper = spegel.NewAgentBootstrapper(cfg.ServerURL, cfg.Token, cfg.DataDir)
-	conf.HandlerFunc = func(conf *spegel.Config, router *mux.Router) error {
-		// Create and bind a new authenticator using the configured client CA
-		authArgs := []string{"--client-ca-file=" + conf.ClientCAFile}
-		auth, err := authenticator.FromArgs(authArgs)
-		if err != nil {
-			return err
-		}
-		conf.AuthFunc = func() apiauth.Request {
-			return auth
-		}
+	registry := spegel.DefaultRegistry
+	registry.Bootstrapper = spegel.NewAgentBootstrapper(cfg.ServerURL, cfg.Token, cfg.DataDir)
+	registry.Router = func(ctx context.Context, nodeConfig *config.Node) (*mux.Router, error) {
+		return https.Start(ctx, nodeConfig, nil)
+	}
 
-		// Create a new server and listen on the configured port
-		server := &http.Server{
-			Handler: router,
-			Addr:    ":" + conf.RegistryPort,
-			TLSConfig: &tls.Config{
-				ClientAuth: tls.RequestClientCert,
-			},
-		}
-		go func() {
-			if err := server.ListenAndServeTLS(conf.ServerCertFile, conf.ServerKeyFile); err != nil && !errors.Is(err, http.ErrServerClosed) {
-				logrus.Fatalf("registry server failed: %v", err)
-			}
-		}()
-		return nil
+	// same deal for metrics - these are not used if the extra metrics listener is not enabled.
+	metrics := k3smetrics.DefaultMetrics
+	metrics.Router = func(ctx context.Context, nodeConfig *config.Node) (*mux.Router, error) {
+		return https.Start(ctx, nodeConfig, nil)
+	}
+
+	// and for pprof as well
+	pprof := profile.DefaultProfiler
+	pprof.Router = func(ctx context.Context, nodeConfig *config.Node) (*mux.Router, error) {
+		return https.Start(ctx, nodeConfig, nil)
 	}
 
 	return agent.Run(contextCtx, cfg)

pkg/cli/cmds/agent.go

@@ -20,6 +20,7 @@ type Agent struct {
 	LBServerPort             int
 	ResolvConf               string
 	DataDir                  string
+	BindAddress              string
 	NodeIP                   cli.StringSlice
 	NodeExternalIP           cli.StringSlice
 	NodeName                 string
@@ -36,6 +37,7 @@ type Agent struct {
 	VPNAuth                  string
 	VPNAuthFile              string
 	Debug                    bool
+	EnablePProf              bool
 	Rootless                 bool
 	RootlessAlreadyUnshared  bool
 	WithNodeID               bool
@@ -226,6 +228,16 @@ var (
 		Usage:       "(agent/containerd) Disables containerd's fallback default registry endpoint when a mirror is configured for that registry",
 		Destination: &AgentConfig.ContainerdNoDefault,
 	}
+	EnablePProfFlag = &cli.BoolFlag{
+		Name:        "enable-pprof",
+		Usage:       "(experimental) Enable pprof endpoint on supervisor port",
+		Destination: &AgentConfig.EnablePProf,
+	}
+	BindAddressFlag = &cli.StringFlag{
+		Name:        "bind-address",
+		Usage:       "(listener) " + version.Program + " bind address (default: 0.0.0.0)",
+		Destination: &AgentConfig.BindAddress,
+	}
 )
 
 func NewAgentCommand(action func(ctx *cli.Context) error) cli.Command {
@@ -278,6 +290,7 @@ func NewAgentCommand(action func(ctx *cli.Context) error) cli.Command {
 			DisableDefaultRegistryEndpointFlag,
 			AirgapExtraRegistryFlag,
 			NodeIPFlag,
+			BindAddressFlag,
 			NodeExternalIPFlag,
 			ResolvConfFlag,
 			FlannelIfaceFlag,
@@ -286,6 +299,7 @@ func NewAgentCommand(action func(ctx *cli.Context) error) cli.Command {
 			ExtraKubeletArgs,
 			ExtraKubeProxyArgs,
 			// Experimental flags
+			EnablePProfFlag,
 			&cli.BoolFlag{
 				Name:        "rootless",
 				Usage:       "(experimental) Run rootless",

pkg/cli/cmds/server.go

@@ -48,8 +48,6 @@ type Server struct {
 	HelmJobImage             string
 	TLSSan                   cli.StringSlice
 	TLSSanSecurity           bool
-	BindAddress              string
-	EnablePProf              bool
 	ExtraAPIArgs             cli.StringSlice
 	ExtraEtcdArgs            cli.StringSlice
 	ExtraSchedulerArgs       cli.StringSlice
@@ -87,6 +85,7 @@ type Server struct {
 	EncryptSkip              bool
 	SystemDefaultRegistry    string
 	StartupHooks             []StartupHook
+	SupervisorMetrics        bool
 	EtcdSnapshotName         string
 	EtcdDisableSnapshots     bool
 	EtcdExposeMetrics        bool
@@ -178,11 +177,7 @@ var ServerFlags = []cli.Flag{
 	VModule,
 	LogFile,
 	AlsoLogToStderr,
-	&cli.StringFlag{
-		Name:        "bind-address",
-		Usage:       "(listener) " + version.Program + " bind address (default: 0.0.0.0)",
-		Destination: &ServerConfig.BindAddress,
-	},
+	BindAddressFlag,
 	&cli.IntFlag{
 		Name:        "https-listen-port",
 		Usage:       "(listener) HTTPS listen port",
@@ -493,9 +488,14 @@ var ServerFlags = []cli.Flag{
 	},
 	&cli.BoolFlag{
 		Name:        "embedded-registry",
-		Usage:       "(experimental/components) Enable embedded distributed container registry; requires use of embedded containerd",
+		Usage:       "(experimental/components) Enable embedded distributed container registry; requires use of embedded containerd; when enabled agents will also listen on the supervisor port",
 		Destination: &ServerConfig.EmbeddedRegistry,
 	},
+	&cli.BoolFlag{
+		Name:        "supervisor-metrics",
+		Usage:       "(experimental/components) Enable serving " + version.Program + " internal metrics on the supervisor port; when enabled agents will also listen on the supervisor port",
+		Destination: &ServerConfig.SupervisorMetrics,
+	},
 	NodeNameFlag,
 	WithNodeIDFlag,
 	NodeLabels,
@@ -534,11 +534,7 @@ var ServerFlags = []cli.Flag{
 		Destination: &ServerConfig.EncryptSecrets,
 	},
 	// Experimental flags
-	&cli.BoolFlag{
-		Name:        "enable-pprof",
-		Usage:       "(experimental) Enable pprof endpoint on supervisor port",
-		Destination: &ServerConfig.EnablePProf,
-	},
+	EnablePProfFlag,
 	&cli.BoolFlag{
 		Name:        "rootless",
 		Usage:       "(experimental) Run rootless",

pkg/cli/server/server.go

@@ -12,13 +12,16 @@ import (
 	systemd "github.com/coreos/go-systemd/v22/daemon"
 	"github.com/gorilla/mux"
 	"github.com/k3s-io/k3s/pkg/agent"
+	"github.com/k3s-io/k3s/pkg/agent/https"
 	"github.com/k3s-io/k3s/pkg/agent/loadbalancer"
 	"github.com/k3s-io/k3s/pkg/cli/cmds"
 	"github.com/k3s-io/k3s/pkg/clientaccess"
 	"github.com/k3s-io/k3s/pkg/daemons/config"
 	"github.com/k3s-io/k3s/pkg/datadir"
 	"github.com/k3s-io/k3s/pkg/etcd"
+	k3smetrics "github.com/k3s-io/k3s/pkg/metrics"
 	"github.com/k3s-io/k3s/pkg/proctitle"
+	"github.com/k3s-io/k3s/pkg/profile"
 	"github.com/k3s-io/k3s/pkg/rootless"
 	"github.com/k3s-io/k3s/pkg/server"
 	"github.com/k3s-io/k3s/pkg/spegel"
@@ -30,7 +33,6 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 	utilnet "k8s.io/apimachinery/pkg/util/net"
-	"k8s.io/apiserver/pkg/authentication/authenticator"
 	kubeapiserverflag "k8s.io/component-base/cli/flag"
 	"k8s.io/kubernetes/pkg/controlplane/apiserver/options"
 	utilsnet "k8s.io/utils/net"
@@ -136,12 +138,11 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 	serverConfig.ControlConfig.ServiceLBNamespace = cfg.ServiceLBNamespace
 	serverConfig.ControlConfig.SANs = util.SplitStringSlice(cfg.TLSSan)
 	serverConfig.ControlConfig.SANSecurity = cfg.TLSSanSecurity
-	serverConfig.ControlConfig.BindAddress = cfg.BindAddress
+	serverConfig.ControlConfig.BindAddress = cmds.AgentConfig.BindAddress
 	serverConfig.ControlConfig.SupervisorPort = cfg.SupervisorPort
 	serverConfig.ControlConfig.HTTPSPort = cfg.HTTPSPort
 	serverConfig.ControlConfig.APIServerPort = cfg.APIServerPort
 	serverConfig.ControlConfig.APIServerBindAddress = cfg.APIServerBindAddress
-	serverConfig.ControlConfig.EnablePProf = cfg.EnablePProf
 	serverConfig.ControlConfig.ExtraAPIArgs = cfg.ExtraAPIArgs
 	serverConfig.ControlConfig.ExtraControllerArgs = cfg.ExtraControllerArgs
 	serverConfig.ControlConfig.ExtraEtcdArgs = cfg.ExtraEtcdArgs
@@ -174,6 +175,7 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 	serverConfig.ControlConfig.EncryptSecrets = cfg.EncryptSecrets
 	serverConfig.ControlConfig.EtcdExposeMetrics = cfg.EtcdExposeMetrics
 	serverConfig.ControlConfig.EtcdDisableSnapshots = cfg.EtcdDisableSnapshots
+	serverConfig.ControlConfig.SupervisorMetrics = cfg.SupervisorMetrics
 	serverConfig.ControlConfig.VLevel = cmds.LogConfig.VLevel
 	serverConfig.ControlConfig.VModule = cmds.LogConfig.VModule
 
@@ -406,6 +408,7 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 	}
 
 	tlsMinVersionArg := getArgValueFromList("tls-min-version", serverConfig.ControlConfig.ExtraAPIArgs)
+	serverConfig.ControlConfig.MinTLSVersion = tlsMinVersionArg
 	serverConfig.ControlConfig.TLSMinVersion, err = kubeapiserverflag.TLSVersion(tlsMinVersionArg)
 	if err != nil {
 		return errors.Wrap(err, "invalid tls-min-version")
@@ -435,6 +438,7 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 		}
 		serverConfig.ControlConfig.ExtraAPIArgs = append(serverConfig.ControlConfig.ExtraAPIArgs, "tls-cipher-suites="+strings.Join(tlsCipherSuites, ","))
 	}
+	serverConfig.ControlConfig.CipherSuites = tlsCipherSuites
 	serverConfig.ControlConfig.TLSCipherSuites, err = kubeapiserverflag.TLSCipherSuites(tlsCipherSuites)
 	if err != nil {
 		return errors.Wrap(err, "invalid tls-cipher-suites")
@@ -556,28 +560,36 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 		go getAPIAddressFromEtcd(ctx, serverConfig, agentConfig)
 	}
 
+	// Until the agent is run and retrieves config from the server, we won't know
+	// if the embedded registry is enabled. If it is not enabled, these are not
+	// used as the registry is never started.
+	registry := spegel.DefaultRegistry
+	registry.Bootstrapper = spegel.NewChainingBootstrapper(
+		spegel.NewServerBootstrapper(&serverConfig.ControlConfig),
+		spegel.NewAgentBootstrapper(cfg.ServerURL, token, agentConfig.DataDir),
+		spegel.NewSelfBootstrapper(),
+	)
+	registry.Router = func(ctx context.Context, nodeConfig *config.Node) (*mux.Router, error) {
+		return https.Start(ctx, nodeConfig, serverConfig.ControlConfig.Runtime)
+	}
+
+	// same deal for metrics - these are not used if the extra metrics listener is not enabled.
+	metrics := k3smetrics.DefaultMetrics
+	metrics.Router = func(ctx context.Context, nodeConfig *config.Node) (*mux.Router, error) {
+		return https.Start(ctx, nodeConfig, serverConfig.ControlConfig.Runtime)
+	}
+
+	// and for pprof as well
+	pprof := profile.DefaultProfiler
+	pprof.Router = func(ctx context.Context, nodeConfig *config.Node) (*mux.Router, error) {
+		return https.Start(ctx, nodeConfig, serverConfig.ControlConfig.Runtime)
+	}
+
 	if cfg.DisableAgent {
 		agentConfig.ContainerRuntimeEndpoint = "/dev/null"
 		return agent.RunStandalone(ctx, agentConfig)
 	}
 
-	if cfg.EmbeddedRegistry {
-		conf := spegel.DefaultRegistry
-		conf.Bootstrapper = spegel.NewChainingBootstrapper(
-			spegel.NewServerBootstrapper(&serverConfig.ControlConfig),
-			spegel.NewAgentBootstrapper(cfg.ServerURL, token, agentConfig.DataDir),
-			spegel.NewSelfBootstrapper(),
-		)
-		conf.HandlerFunc = func(_ *spegel.Config, router *mux.Router) error {
-			router.NotFoundHandler = serverConfig.ControlConfig.Runtime.Handler
-			serverConfig.ControlConfig.Runtime.Handler = router
-			return nil
-		}
-		conf.AuthFunc = func() authenticator.Request {
-			return serverConfig.ControlConfig.Runtime.Authenticator
-		}
-	}
-
 	return agent.Run(ctx, agentConfig)
 }
 

pkg/cluster/https.go

@@ -4,17 +4,16 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
-	"fmt"
 	"io"
 	"log"
 	"net"
 	"net/http"
-	"net/http/pprof"
 	"os"
 	"path/filepath"
+	"strconv"
 
-	"github.com/gorilla/mux"
 	"github.com/k3s-io/k3s/pkg/daemons/config"
+	"github.com/k3s-io/k3s/pkg/util"
 	"github.com/k3s-io/k3s/pkg/version"
 	"github.com/rancher/dynamiclistener"
 	"github.com/rancher/dynamiclistener/factory"
@@ -24,7 +23,6 @@ import (
 	"github.com/rancher/wrangler/v3/pkg/generated/controllers/core"
 	"github.com/sirupsen/logrus"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	utilsnet "k8s.io/utils/net"
 )
 
 // newListener returns a new TCP listener and HTTP request handler using dynamiclistener.
@@ -43,11 +41,7 @@ func (c *Cluster) newListener(ctx context.Context) (net.Listener, http.Handler,
 			os.Remove(filepath.Join(c.config.DataDir, "tls/dynamic-cert.json"))
 		}
 	}
-	ip := c.config.BindAddress
-	if utilsnet.IsIPv6String(ip) {
-		ip = fmt.Sprintf("[%s]", ip)
-	}
-	tcp, err := dynamiclistener.NewTCPListener(ip, c.config.SupervisorPort)
+	tcp, err := util.ListenWithLoopback(ctx, c.config.BindAddress, strconv.Itoa(c.config.SupervisorPort))
 	if err != nil {
 		return nil, nil, err
 	}
@@ -114,17 +108,6 @@ func (c *Cluster) initClusterAndHTTPS(ctx context.Context) error {
 		return err
 	}
 
-	if c.config.EnablePProf {
-		mux := mux.NewRouter().SkipClean(true)
-		mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
-		mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
-		mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
-		mux.HandleFunc("/debug/pprof/trace", pprof.Trace)
-		mux.PathPrefix("/debug/pprof/").HandlerFunc(pprof.Index)
-		mux.NotFoundHandler = handler
-		handler = mux
-	}
-
 	// Create a HTTP server with the registered request handlers, using logrus for logging
 	server := http.Server{
 		Handler: handler,

pkg/daemons/config/types.go

@@ -41,6 +41,8 @@ type Node struct {
 	ImageServiceEndpoint     string
 	NoFlannel                bool
 	SELinux                  bool
+	EnablePProf              bool
+	SupervisorMetrics        bool
 	EmbeddedRegistry         bool
 	FlannelBackend           string
 	FlannelConfFile          string
@@ -128,6 +130,8 @@ type Agent struct {
 	AirgapExtraRegistry     []string
 	DisableCCM              bool
 	DisableNPC              bool
+	MinTLSVersion           string
+	CipherSuites            []string
 	Rootless                bool
 	ProtectKernelDefaults   bool
 	DisableServiceLB        bool
@@ -159,6 +163,7 @@ type CriticalControlArgs struct {
 	EgressSelectorMode    string       `cli:"egress-selector-mode"`
 	ServiceIPRange        *net.IPNet   `cli:"service-cidr"`
 	ServiceIPRanges       []*net.IPNet `cli:"service-cidr"`
+	SupervisorMetrics     bool         `cli:"supervisor-metrics"`
 }
 
 type Control struct {
@@ -191,7 +196,6 @@ type Control struct {
 	DisableServiceLB         bool
 	Rootless                 bool
 	ServiceLBNamespace       string
-	EnablePProf              bool
 	ExtraAPIArgs             []string
 	ExtraControllerArgs      []string
 	ExtraCloudControllerArgs []string
@@ -208,8 +212,10 @@ type Control struct {
 	ClusterResetRestorePath  string
 	EncryptForce             bool
 	EncryptSkip              bool
-	TLSMinVersion            uint16
-	TLSCipherSuites          []uint16
+	MinTLSVersion            string
+	CipherSuites             []string
+	TLSMinVersion            uint16        `json:"-"`
+	TLSCipherSuites          []uint16      `json:"-"`
 	EtcdSnapshotName         string        `json:"-"`
 	EtcdDisableSnapshots     bool          `json:"-"`
 	EtcdExposeMetrics        bool          `json:"-"`

pkg/metrics/metrics.go

+package metrics
+
+import (
+	"context"
+	"errors"
+
+	"github.com/gorilla/mux"
+	"github.com/k3s-io/k3s/pkg/agent/https"
+	"github.com/k3s-io/k3s/pkg/daemons/config"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"k8s.io/component-base/metrics/legacyregistry"
+)
+
+// DefaultRegisterer is the implementation of the
+// prometheus Registerer interface that all metrics operations
+// will use.
+var DefaultRegisterer = legacyregistry.Registerer()
+
+// DefaultGatherer  is the implementation of the
+// prometheus Gatherere interface that all metrics operations
+// will use.
+var DefaultGatherer = legacyregistry.DefaultGatherer
+
+// DefaultMetrics is the default instance of a Metrics server
+var DefaultMetrics = &Config{
+	Router: func(context.Context, *config.Node) (*mux.Router, error) {
+		return nil, errors.New("not implemented")
+	},
+}
+
+// Config holds fields for the metrics listener
+type Config struct {
+	// Router will be called to add the metrics API handler to an existing router.
+	Router https.RouterFunc
+}
+
+// Start starts binds the metrics API to an existing HTTP router.
+func (c *Config) Start(ctx context.Context, nodeConfig *config.Node) error {
+	mRouter, err := c.Router(ctx, nodeConfig)
+	if err != nil {
+		return err
+	}
+	mRouter.Handle("/metrics", promhttp.HandlerFor(DefaultGatherer, promhttp.HandlerOpts{}))
+	return nil
+}

pkg/profile/profile.go

+package profile
+
+import (
+	"context"
+	"errors"
+	"net/http/pprof"
+
+	"github.com/gorilla/mux"
+	"github.com/k3s-io/k3s/pkg/agent/https"
+	"github.com/k3s-io/k3s/pkg/daemons/config"
+)
+
+// DefaultProfiler the default instance of a performance profiling server
+var DefaultProfiler = &Config{
+	Router: func(context.Context, *config.Node) (*mux.Router, error) {
+		return nil, errors.New("not implemented")
+	},
+}
+
+// Config holds fields for the pprof listener
+type Config struct {
+	// Router will be called to add the pprof API handler to an existing router.
+	Router https.RouterFunc
+}
+
+// Start starts binds the pprof API to an existing HTTP router.
+func (c *Config) Start(ctx context.Context, nodeConfig *config.Node) error {
+	mRouter, err := c.Router(ctx, nodeConfig)
+	if err != nil {
+		return err
+	}
+	mRouter.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
+	mRouter.HandleFunc("/debug/pprof/profile", pprof.Profile)
+	mRouter.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
+	mRouter.HandleFunc("/debug/pprof/trace", pprof.Trace)
+	mRouter.PathPrefix("/debug/pprof/").HandlerFunc(pprof.Index)
+	return nil
+}

pkg/spegel/spegel.go

@@ -13,13 +13,12 @@ import (
 	"time"
 
 	"github.com/containerd/containerd/remotes/docker"
+	"github.com/k3s-io/k3s/pkg/agent/https"
 	"github.com/k3s-io/k3s/pkg/clientaccess"
 	"github.com/k3s-io/k3s/pkg/daemons/config"
 	"github.com/k3s-io/k3s/pkg/version"
 	"github.com/rancher/dynamiclistener/cert"
 	"k8s.io/apimachinery/pkg/util/wait"
-	"k8s.io/apiserver/pkg/authentication/authenticator"
-	"k8s.io/apiserver/pkg/authentication/request/union"
 	"k8s.io/utils/ptr"
 
 	"github.com/go-logr/logr"
@@ -43,11 +42,8 @@ import (
 // DefaultRegistry is the default instance of a Spegel distributed registry
 var DefaultRegistry = &Config{
 	Bootstrapper: NewSelfBootstrapper(),
-	HandlerFunc: func(_ *Config, _ *mux.Router) error {
-		return errors.New("not implemented")
-	},
-	AuthFunc: func() authenticator.Request {
-		return union.New(nil)
+	Router: func(context.Context, *config.Node) (*mux.Router, error) {
+		return nil, errors.New("not implemented")
 	},
 }
 
@@ -60,9 +56,6 @@ var (
 	resolveLatestTag = false
 )
 
-type authFunc func() authenticator.Request
-type handlerFunc func(config *Config, router *mux.Router) error
-
 // Config holds fields for a distributed registry
 type Config struct {
 	ClientCAFile   string
@@ -89,10 +82,7 @@ type Config struct {
 	Bootstrapper routing.Bootstrapper
 
 	// HandlerFunc will be called to add the registry API handler to an existing router.
-	HandlerFunc handlerFunc
-
-	// Authenticator will be called to retrieve an authenticator used to validate the request to the registry API.
-	AuthFunc authFunc
+	Router https.RouterFunc
 }
 
 // These values are not currently configurable
@@ -237,13 +227,12 @@ func (c *Config) Start(ctx context.Context, nodeConfig *config.Node) error {
 	// Track images available in containerd and publish via p2p router
 	go state.Track(ctx, ociClient, router, resolveLatestTag)
 
-	mRouter := mux.NewRouter().SkipClean(true)
-	mRouter.Use(c.authMiddleware())
-	mRouter.PathPrefix("/v2").Handler(regSvr.Handler)
-	mRouter.PathPrefix("/v1-" + version.Program + "/p2p").Handler(c.peerInfo())
-	if err := c.HandlerFunc(c, mRouter); err != nil {
+	mRouter, err := c.Router(ctx, nodeConfig)
+	if err != nil {
 		return err
 	}
+	mRouter.PathPrefix("/v2").Handler(regSvr.Handler)
+	mRouter.PathPrefix("/v1-" + version.Program + "/p2p").Handler(c.peerInfo())
 
 	// Wait up to 5 seconds for the p2p network to find peers. This will return
 	// immediately if the node is bootstrapping from itself.
@@ -269,16 +258,3 @@ func (c *Config) peerInfo() http.HandlerFunc {
 		fmt.Fprintf(resp, "%s/p2p/%s", info.Addrs[0].String(), info.ID.String())
 	})
 }
-
-// authMiddleware calls the configured authenticator to gate access to the registry API
-func (c *Config) authMiddleware() mux.MiddlewareFunc {
-	return func(next http.Handler) http.Handler {
-		return http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
-			if _, ok, err := c.AuthFunc().AuthenticateRequest(req); !ok || err != nil {
-				http.Error(resp, "Unauthorized", http.StatusUnauthorized)
-				return
-			}
-			next.ServeHTTP(resp, req)
-		})
-	}
-}

pkg/util/net.go

 package util
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net"
 	"os"
 	"strings"
+	"time"
 
+	"github.com/rancher/wrangler/v3/pkg/merr"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 	apinet "k8s.io/apimachinery/pkg/util/net"
@@ -319,3 +322,111 @@ func getIPFromInterface(ifaceName string) (string, error) {
 
 	return "", fmt.Errorf("can't find ip for interface %s", ifaceName)
 }
+
+type multiListener struct {
+	listeners []net.Listener
+	closing   chan struct{}
+	conns     chan acceptRes
+}
+
+type acceptRes struct {
+	conn net.Conn
+	err  error
+}
+
+// explicit interface check
+var _ net.Listener = &multiListener{}
+
+var loopbacks = []string{"127.0.0.1", "::1"}
+
+// ListenWithLoopback listens on the given address, as well as on IPv4 and IPv6 loopback addresses.
+// If the address is a wildcard, the listener is return unwrapped.
+func ListenWithLoopback(ctx context.Context, addr string, port string) (net.Listener, error) {
+	lc := &net.ListenConfig{
+		KeepAlive: 3 * time.Minute,
+		Control:   permitReuse,
+	}
+	l, err := lc.Listen(ctx, "tcp", net.JoinHostPort(addr, port))
+	if err != nil {
+		return nil, err
+	}
+
+	// If we're listening on a wildcard address, we don't need to wrap with the other loopback addresses
+	switch addr {
+	case "", "::", "0.0.0.0":
+		return l, nil
+	}
+
+	ml := &multiListener{
+		listeners: []net.Listener{l},
+		closing:   make(chan struct{}),
+		conns:     make(chan acceptRes),
+	}
+
+	for _, laddr := range loopbacks {
+		if laddr == addr {
+			continue
+		}
+		if l, err := lc.Listen(ctx, "tcp", net.JoinHostPort(laddr, port)); err == nil {
+			ml.listeners = append(ml.listeners, l)
+		} else {
+			logrus.Debugf("Failed to listen on %s: %v", net.JoinHostPort(laddr, port), err)
+		}
+	}
+
+	for i := range ml.listeners {
+		go ml.accept(ml.listeners[i])
+	}
+
+	return ml, nil
+}
+
+// Addr returns the address of the non-loopback address that this multiListener is listening on
+func (ml *multiListener) Addr() net.Addr {
+	return ml.listeners[0].Addr()
+}
+
+// Close closes all the listeners
+func (ml *multiListener) Close() error {
+	close(ml.closing)
+	var errs merr.Errors
+	for i := range ml.listeners {
+		err := ml.listeners[i].Close()
+		if err != nil {
+			errs = append(errs, err)
+		}
+	}
+	return merr.NewErrors(errs)
+}
+
+// Accept returns a Conn/err pair from one of the waiting listeners
+func (ml *multiListener) Accept() (net.Conn, error) {
+	select {
+	case res, ok := <-ml.conns:
+		if ok {
+			return res.conn, res.err
+		}
+		return nil, fmt.Errorf("connection channel closed")
+	case <-ml.closing:
+		return nil, fmt.Errorf("listener closed")
+	}
+}
+
+// accept runs a loop, accepting connections and trying to send on the result channel
+func (ml *multiListener) accept(listener net.Listener) {
+	for {
+		conn, err := listener.Accept()
+		r := acceptRes{
+			conn: conn,
+			err:  err,
+		}
+		select {
+		case ml.conns <- r:
+		case <-ml.closing:
+			if r.err == nil {
+				r.conn.Close()
+			}
+			return
+		}
+	}
+}

pkg/util/net_unix.go

+//go:build !windows
+// +build !windows
+
+package util
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// permitReuse enables port and address sharing on the socket
+func permitReuse(network, addr string, conn syscall.RawConn) error {
+	return conn.Control(func(fd uintptr) {
+		syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+		syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, unix.SO_REUSEADDR, 1)
+	})
+}

pkg/util/net_windows.go

+//go:build windows
+// +build windows
+
+package util
+
+import "syscall"
+
+// permitReuse is a no-op; port and address reuse is not supported on Windows
+func permitReuse(network, addr string, conn syscall.RawConn) error {
+	return nil
+}