fix: process leak

https://www.ohyee.cc/post/note_zombie_process

cron/spider/request.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"syscall"
 
 	"github.com/OhYee/blotter/output"
 	"github.com/chromedp/chromedp"
@@ -113,5 +114,12 @@ func getHTMLWithJS(u string) string {
 	if err != nil {
 		output.ErrOutput.Println(u, err)
 	}
+
+	defer func() {
+		if process := chromedp.FromContext(ctx3).Browser.Process(); process != nil {
+			fmt.Println(process.Signal(syscall.SIGTERM))
+		}
+	}()
+
 	return res
 }

main.go

@@ -12,6 +12,7 @@ import (
 	"github.com/OhYee/blotter/output"
 	"github.com/OhYee/blotter/register"
 	"github.com/OhYee/blotter/utils/initial"
+	"github.com/OhYee/blotter/utils/reaper"
 )
 
 var (
@@ -44,6 +45,8 @@ func parseFlags() {
 }
 
 func main() {
+	go reaper.Reap()
+
 	parseFlags()
 	register.SetContext("version", _version)
 	register.SetContext("spiderURL", url)

utils/reaper/reaper.go

@@ -0,0 +1,136 @@
+/**
+ * Copy from https://github.com/ramr/go-reaper/blob/master/reaper.go
+ */
+package reaper
+
+/*  Note:  This is a *nix only implementation.  */
+
+//  Prefer #include style directives.
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+type Config struct {
+	Pid              int
+	Options          int
+	DisablePid1Check bool
+	Debug            bool
+}
+
+// Handle death of child (SIGCHLD) messages. Pushes the signal onto the
+// notifications channel if there is a waiter.
+func sigChildHandler(notifications chan os.Signal) {
+	var sigs = make(chan os.Signal, 3)
+	signal.Notify(sigs, syscall.SIGCHLD)
+
+	for {
+		var sig = <-sigs
+		select {
+		case notifications <- sig: /*  published it.  */
+		default:
+			/*
+			 *  Notifications channel full - drop it to the
+			 *  floor. This ensures we don't fill up the SIGCHLD
+			 *  queue. The reaper just waits for any child
+			 *  process (pid=-1), so we ain't loosing it!! ;^)
+			 */
+		}
+	}
+
+} /*  End of function  sigChildHandler.  */
+
+// Be a good parent - clean up behind the children.
+func reapChildren(config Config) {
+	var notifications = make(chan os.Signal, 1)
+
+	go sigChildHandler(notifications)
+
+	pid := config.Pid
+	opts := config.Options
+
+	for {
+		var sig = <-notifications
+		if config.Debug {
+			fmt.Printf(" - Received signal %v\n", sig)
+		}
+		for {
+			var wstatus syscall.WaitStatus
+
+			/*
+			 *  Reap 'em, so that zombies don't accumulate.
+			 *  Plants vs. Zombies!!
+			 */
+			pid, err := syscall.Wait4(pid, &wstatus, opts, nil)
+			for syscall.EINTR == err {
+				pid, err = syscall.Wait4(pid, &wstatus, opts, nil)
+			}
+
+			if syscall.ECHILD == err {
+				break
+			}
+
+			if config.Debug {
+				fmt.Printf(" - Grim reaper cleanup: pid=%d, wstatus=%+v\n",
+					pid, wstatus)
+			}
+
+		}
+	}
+
+} /*   End of function  reapChildren.  */
+
+/*
+ *  ======================================================================
+ *  Section: Exported functions
+ *  ======================================================================
+ */
+
+// Normal entry point for the reaper code. Start reaping children in the
+// background inside a goroutine.
+func Reap() {
+	/*
+	 *  Only reap processes if we are taking over init's duties aka
+	 *  we are running as pid 1 inside a docker container. The default
+	 *  is to reap all processes.
+	 */
+	Start(Config{
+		Pid:              -1,
+		Options:          0,
+		DisablePid1Check: false,
+	})
+
+} /*  End of [exported] function  Reap.  */
+
+// Entry point for invoking the reaper code with a specific configuration.
+// The config allows you to bypass the pid 1 checks, so handle with care.
+// The child processes are reaped in the background inside a goroutine.
+func Start(config Config) {
+	/*
+	 *  Start the Reaper with configuration options. This allows you to
+	 *  reap processes even if the current pid isn't running as pid 1.
+	 *  So ... use with caution!!
+	 *
+	 *  In most cases, you are better off just using Reap() as that
+	 *  checks if we are running as Pid 1.
+	 */
+	if !config.DisablePid1Check {
+		mypid := os.Getpid()
+		if 1 != mypid {
+			if config.Debug {
+				fmt.Printf(" - Grim reaper disabled, pid not 1\n")
+			}
+			return
+		}
+	}
+
+	/*
+	 *  Ok, so either pid 1 checks are disabled or we are the grandma
+	 *  of 'em all, either way we get to play the grim reaper.
+	 *  You will be missed, Terry Pratchett!! RIP
+	 */
+	go reapChildren(config)
+
+} /*  End of [exported] function  Start.  */