feat(kic 2.0) add profiling

Signed-off-by: Tharun <rajendrantharun@live.com>

CHANGELOG.md

@@ -37,6 +37,8 @@ released and the release notes may change significantly before then.
 
 #### Added
 
+- added support for profiling in KIC 2.0.
+  [#1408](https://github.com/Kong/kubernetes-ingress-controller/pull/1408)
 - support for [UDP][kong-udp] via the new `UDPIngress` API.
 - `--watch-namespace` now supports multiple distinct namespaces versus simply
   supporting all namespaces (the default) or a single namespace. To watch

railgun/internal/diagnostics/server.go

@@ -0,0 +1,54 @@
+package diagnostics
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/kong/kubernetes-ingress-controller/railgun/internal/mgrutils"
+	"github.com/kong/kubernetes-ingress-controller/railgun/pkg/config"
+	"github.com/sirupsen/logrus"
+)
+
+type diagnosticsServer struct {
+	logger logrus.FieldLogger
+	mux    *http.ServeMux
+}
+
+func NewDiagnosticsServer(enableProfiling bool, log logrus.FieldLogger) *diagnosticsServer {
+	mux := http.NewServeMux()
+	if enableProfiling {
+		mgrutils.Install(mux)
+	}
+	return &diagnosticsServer{
+		logger: log,
+		mux:    mux,
+	}
+}
+
+func (s *diagnosticsServer) Start(ctx context.Context) error {
+	httpServer := &http.Server{Addr: fmt.Sprintf(":%d", config.DiagnosticsPort), Handler: s.mux}
+	errChan := make(chan error)
+	go func() {
+		err := httpServer.ListenAndServe()
+		if err != nil {
+			switch err {
+			case http.ErrServerClosed:
+				s.logger.Info("shutting down diagnostics server")
+			default:
+				s.logger.Error(err, "could not start a diagnostics server")
+				errChan <- err
+			}
+		}
+	}()
+
+	s.logger.Info("started diagnostics server at port ", config.DiagnosticsPort)
+
+	select {
+	case <-ctx.Done():
+		s.logger.Info("stopping down diagnostics server")
+		return httpServer.Shutdown(context.Background())
+	case err := <-errChan:
+		return err
+	}
+}

railgun/internal/mgrutils/profiling.go

@@ -0,0 +1,28 @@
+package mgrutils
+
+import (
+	"net/http"
+	"net/http/pprof"
+)
+
+// Install adds the Profiling webservice to the given mux.
+func Install(mux *http.ServeMux) {
+	mux.HandleFunc("/debug/pprof", redirectTo("/debug/pprof/"))
+	mux.HandleFunc("/debug/pprof/", pprof.Index)
+	mux.HandleFunc("/debug/pprof/heap", pprof.Index)
+	mux.HandleFunc("/debug/pprof/mutex", pprof.Index)
+	mux.HandleFunc("/debug/pprof/goroutine", pprof.Index)
+	mux.HandleFunc("/debug/pprof/threadcreate", pprof.Index)
+	mux.HandleFunc("/debug/pprof/block", pprof.Index)
+	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)
+}
+
+// redirectTo redirects request to a certain destination.
+func redirectTo(to string) func(http.ResponseWriter, *http.Request) {
+	return func(rw http.ResponseWriter, req *http.Request) {
+		http.Redirect(rw, req, to, http.StatusFound)
+	}
+}

railgun/manager/run.go

@@ -23,6 +23,7 @@ import (
 	configurationv1beta1 "github.com/kong/kubernetes-ingress-controller/railgun/apis/configuration/v1beta1"
 	"github.com/kong/kubernetes-ingress-controller/railgun/controllers/configuration"
 	kongctrl "github.com/kong/kubernetes-ingress-controller/railgun/controllers/configuration"
+	"github.com/kong/kubernetes-ingress-controller/railgun/internal/diagnostics"
 	"github.com/kong/kubernetes-ingress-controller/railgun/internal/mgrutils"
 	"github.com/kong/kubernetes-ingress-controller/railgun/internal/proxy"
 	"github.com/kong/kubernetes-ingress-controller/railgun/pkg/config"
@@ -268,6 +269,13 @@ func Run(ctx context.Context, c *config.Config) error {
 		setupLog.Info("anonymous reports disabled, skipping")
 	}
 
+	diagnosticsServer := diagnostics.NewDiagnosticsServer(c.EnableProfiling, deprecatedLogger.WithField("component", "metadata-server"))
+	go func() {
+		setupLog.Info("starting diagnostics server")
+		if err := diagnosticsServer.Start(ctx); err != nil {
+			setupLog.Error(err, "unable to start diagnostics server")
+		}
+	}()
 	setupLog.Info("starting manager")
 	return mgr.Start(ctx)
 }

railgun/pkg/config/config.go

@@ -68,6 +68,9 @@ type Config struct {
 
 	// Admission Webhook server config
 	AdmissionServer admission.ServerConfig
+
+	// Performance
+	EnableProfiling bool
 }
 
 // -----------------------------------------------------------------------------
@@ -157,6 +160,9 @@ func (c *Config) FlagSet() *pflag.FlagSet {
 	flagSet.StringVar(&c.AdmissionServer.Key, "admission-webhook-key", "",
 		`admission server PEM private key value`)
 
+	// Misc
+	flagSet.BoolVar(&c.EnableProfiling, "profiling", false, "Enable profiling via web interface host:port/debug/pprof/")
+
 	return &flagSet.FlagSet
 }
 

railgun/pkg/config/consts.go

@@ -16,3 +16,6 @@ const HealthzPort = 10254
 // Similar to HealthzPort, it may be used in existing user deployment configurations, and its
 // literal value is used in several stock manifests, which must be updated along with this value.
 const MetricsPort = 10255
+
+// DiagnosticsPort is the default port of the manager's diagnostics service listens on.
+const DiagnosticsPort = 10256

railgun/test/integration/controller_test.go

@@ -57,3 +57,20 @@ func TestMetricsEndpoint(t *testing.T) {
 		return len(v) > 0
 	}, ingressWait, waitTick)
 }
+
+func TestProfilingEndpoint(t *testing.T) {
+	if useLegacyKIC() {
+		t.Skip("profiling endpoint behaves differently in legacy KIC")
+	}
+	_ = proxyReady()
+	assert.Eventually(t, func() bool {
+		profilingURL := fmt.Sprintf("http://localhost:%v/debug/pprof/", config.DiagnosticsPort)
+		resp, err := httpc.Get(profilingURL)
+		if err != nil {
+			t.Logf("WARNING: error while waiting for %s: %v", profilingURL, err)
+			return false
+		}
+		defer resp.Body.Close()
+		return resp.StatusCode == http.StatusOK
+	}, ingressWait, waitTick)
+}

railgun/test/integration/suite_test.go

@@ -234,6 +234,7 @@ func deployControllers(ctx context.Context, ready chan ktfkind.ProxyReadinessEve
 				"--admission-webhook-listen=172.17.0.1:49023",
 				fmt.Sprintf("--admission-webhook-cert=%s", admissionWebhookCert),
 				fmt.Sprintf("--admission-webhook-key=%s", admissionWebhookKey),
+				"--profiling",
 			})
 			fmt.Fprintf(os.Stderr, "config: %+v\n", config)