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NO-ISSUE: Add opt-in pprof endpoint to machine-controller-manager #189

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Merged
openshift-merge-bot merged 1 commit into from
Jun 23, 2026
+170 −0
Merged

NO-ISSUE: Add opt-in pprof endpoint to machine-controller-manager #189

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21 changes: 21 additions & 0 deletions cmd/manager/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@ package main
import (
"flag"
"fmt"
_ "net/http/pprof"
"os"
"strings"
"time"
Expand Down Expand Up @@ -97,6 +98,18 @@ func main() {
"The address for health checking.",
)

enablePprof := flag.Bool(
"enable-pprof",
false,
"Enable the pprof profiling endpoint.",
)

pprofAddr := flag.String(
"pprof-bind-address",
"127.0.0.1:6060",
"The address for serving pprof profiling endpoints (requires --enable-pprof).",
)
Comment thread
perdasilva marked this conversation as resolved.

// Sets up feature gates (version from build time, default 4 for unknown)
// Default should be changed to 5 once we branch for 5
majorVersion := version.Version.Major
Expand Down Expand Up @@ -231,6 +244,14 @@ func main() {
klog.Fatal(err)
}

if *enablePprof {
if err := mgr.Add(&pprofServer{
Addr: *pprofAddr,
}); err != nil {
klog.Fatalf("Error adding pprof server: %v", err)
}
}
Comment thread
damdo marked this conversation as resolved.

// Start the Cmd
err = mgr.Start(ctrl.SetupSignalHandler())
if err != nil {
Expand Down
105 changes: 105 additions & 0 deletions cmd/manager/main_test.go
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Original file line number Diff line number Diff line change
@@ -0,0 +1,105 @@
package main

import (
"context"
"fmt"
"net"
"net/http"
"testing"
"time"
)

func TestPprofServerResponds(t *testing.T) {
listener, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
t.Fatalf("failed to listen: %v", err)
}
addr := listener.Addr().String()
listener.Close()
Comment thread
perdasilva marked this conversation as resolved.

srv := &pprofServer{
Addr: addr,
}

ctx, cancel := context.WithCancel(context.Background())
defer cancel()

errCh := make(chan error, 1)
go func() {
errCh <- srv.Start(ctx)
}()

var resp *http.Response
for i := 0; i < 20; i++ {
resp, err = http.Get(fmt.Sprintf("http://%s/debug/pprof/", addr))
if err == nil {
break
}
time.Sleep(50 * time.Millisecond)
}
if err != nil {
t.Fatalf("pprof server did not respond: %v", err)
}
defer resp.Body.Close()

if resp.StatusCode != http.StatusOK {
t.Errorf("expected status 200, got %d", resp.StatusCode)
}

cancel()
select {
case err := <-errCh:
if err != nil {
t.Errorf("server returned error on shutdown: %v", err)
}
case <-time.After(10 * time.Second):
t.Fatal("server did not shut down within 10 seconds")
}
}

func TestPprofServerGracefulShutdown(t *testing.T) {
listener, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
t.Fatalf("failed to listen: %v", err)
}
addr := listener.Addr().String()
listener.Close()

srv := &pprofServer{
Addr: addr,
}

ctx, cancel := context.WithCancel(context.Background())

errCh := make(chan error, 1)
go func() {
errCh <- srv.Start(ctx)
}()

for i := 0; i < 20; i++ {
resp, getErr := http.Get(fmt.Sprintf("http://%s/debug/pprof/", addr))
if getErr == nil {
resp.Body.Close()
break
}
time.Sleep(50 * time.Millisecond)
}

cancel()

select {
case err := <-errCh:
if err != nil {
t.Errorf("server returned error on shutdown: %v", err)
}
case <-time.After(5 * time.Second):
t.Fatal("server did not shut down within 5 seconds")
}
}

func TestPprofServerNeedLeaderElection(t *testing.T) {
srv := &pprofServer{}
if srv.NeedLeaderElection() {
t.Error("pprofServer.NeedLeaderElection() returned true, expected false")
}
}
44 changes: 44 additions & 0 deletions cmd/manager/pprof.go
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Original file line number Diff line number Diff line change
@@ -0,0 +1,44 @@
package main

import (
"context"
"fmt"
"net/http"
"time"

"k8s.io/klog/v2"
)

type pprofServer struct {
Addr string
}

func (s *pprofServer) Start(ctx context.Context) error {
srv := &http.Server{
Addr: s.Addr,
Handler: http.DefaultServeMux,
}
klog.Infof("Starting pprof server on %s", s.Addr)

errCh := make(chan error, 1)
go func() {
if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
errCh <- err
}
close(errCh)
}()

select {
case err := <-errCh:
return fmt.Errorf("pprof server failed: %w", err)
case <-ctx.Done():
}

shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
return srv.Shutdown(shutdownCtx)
}

func (s *pprofServer) NeedLeaderElection() bool {
return false
}