kubelet tracing

Signed-off-by: Sally O'Malley <somalley@redhat.com>
Co-authored-by: David Ashpole <dashpole@google.com>

pkg/kubelet/server/server.go

@@ -37,6 +37,7 @@ import (
 	cadvisorapi "github.com/google/cadvisor/info/v1"
 	cadvisorv2 "github.com/google/cadvisor/info/v2"
 	"github.com/google/cadvisor/metrics"
+	oteltrace "go.opentelemetry.io/otel/trace"
 	"google.golang.org/grpc"
 	"k8s.io/klog/v2"
 	"k8s.io/kubernetes/pkg/kubelet/metrics/collectors"
@@ -63,6 +64,7 @@ import (
 	compbasemetrics "k8s.io/component-base/metrics"
 	"k8s.io/component-base/metrics/legacyregistry"
 	runtimeapi "k8s.io/cri-api/pkg/apis/runtime/v1"
+	tracing "k8s.io/component-base/tracing"
 	podresourcesapi "k8s.io/kubelet/pkg/apis/podresources/v1"
 	podresourcesapiv1alpha1 "k8s.io/kubelet/pkg/apis/podresources/v1alpha1"
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
@@ -127,10 +129,13 @@ type containerInterface interface {
 // so we can ensure restful.FilterFunctions are used for all handlers
 type filteringContainer struct {
 	*restful.Container
+	oteltrace.TracerProvider
+
 	registeredHandlePaths []string
 }
 
 func (a *filteringContainer) Handle(path string, handler http.Handler) {
+	handler = tracing.WithTracing(handler, a.TracerProvider, "kubelet")
 	a.HandleWithFilter(path, handler)
 	a.registeredHandlePaths = append(a.registeredHandlePaths, path)
 }
@@ -144,12 +149,13 @@ func ListenAndServeKubeletServer(
 	resourceAnalyzer stats.ResourceAnalyzer,
 	kubeCfg *kubeletconfiginternal.KubeletConfiguration,
 	tlsOptions *TLSOptions,
-	auth AuthInterface) {
+	auth AuthInterface,
+	tp oteltrace.TracerProvider) {
 
 	address := netutils.ParseIPSloppy(kubeCfg.Address)
 	port := uint(kubeCfg.Port)
 	klog.InfoS("Starting to listen", "address", address, "port", port)
-	handler := NewServer(host, resourceAnalyzer, auth, kubeCfg)
+	handler := NewServer(host, resourceAnalyzer, auth, tp, kubeCfg)
 	s := &http.Server{
 		Addr:           net.JoinHostPort(address.String(), strconv.FormatUint(uint64(port), 10)),
 		Handler:        &handler,
@@ -158,6 +164,7 @@ func ListenAndServeKubeletServer(
 		WriteTimeout:   4 * 60 * time.Minute,
 		MaxHeaderBytes: 1 << 20,
 	}
+
 	if tlsOptions != nil {
 		s.TLSConfig = tlsOptions.Config
 		// Passing empty strings as the cert and key files means no
@@ -174,9 +181,14 @@ func ListenAndServeKubeletServer(
 }
 
 // ListenAndServeKubeletReadOnlyServer initializes a server to respond to HTTP network requests on the Kubelet.
-func ListenAndServeKubeletReadOnlyServer(host HostInterface, resourceAnalyzer stats.ResourceAnalyzer, address net.IP, port uint) {
+func ListenAndServeKubeletReadOnlyServer(
+	host HostInterface,
+	resourceAnalyzer stats.ResourceAnalyzer,
+	address net.IP,
+	port uint) {
 	klog.InfoS("Starting to listen read-only", "address", address, "port", port)
-	s := NewServer(host, resourceAnalyzer, nil, nil)
+	// TODO: https://github.com/kubernetes/kubernetes/issues/109829 tracer should use WithPublicEndpoint
+	s := NewServer(host, resourceAnalyzer, nil, oteltrace.NewNoopTracerProvider(), nil)
 
 	server := &http.Server{
 		Addr:           net.JoinHostPort(address.String(), strconv.FormatUint(uint64(port), 10)),
@@ -241,12 +253,15 @@ func NewServer(
 	host HostInterface,
 	resourceAnalyzer stats.ResourceAnalyzer,
 	auth AuthInterface,
+	tp oteltrace.TracerProvider,
 	kubeCfg *kubeletconfiginternal.KubeletConfiguration) Server {
+	rc := &filteringContainer{Container: restful.NewContainer(), TracerProvider: tp}
+
 	server := Server{
 		host:                 host,
 		resourceAnalyzer:     resourceAnalyzer,
 		auth:                 auth,
-		restfulCont:          &filteringContainer{Container: restful.NewContainer()},
+		restfulCont:          rc,
 		metricsBuckets:       sets.NewString(),
 		metricsMethodBuckets: sets.NewString("OPTIONS", "GET", "HEAD", "POST", "PUT", "DELETE", "TRACE", "CONNECT"),
 	}