Wrap syscall.Kill to a wrapper to avoid error in Windows

syscall.Kill is a system library call not available in Windows making it difficult to compile the code as is in Windows and for proper IDE support. So wrapped syscall.Kill to a system specific build constrained implementation to avoid the compile error.

controllers/router_test.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/newscred/webhook-broker/storage/data"
 	storagemocks "github.com/newscred/webhook-broker/storage/mocks"
+	"github.com/newscred/webhook-broker/utils"
 	"github.com/stretchr/testify/mock"
 )
 
@@ -85,7 +86,7 @@ func TestNotifyOnInterrupt(t *testing.T) {
 		<-stop
 		wg.Done()
 	}()
-	syscall.Kill(syscall.Getpid(), syscall.SIGTERM)
+	utils.NewProcessKiller().Kill(syscall.Getpid(), syscall.SIGTERM)
 	if waitTimeout(&wg, 100*time.Millisecond) {
 		t.Fail()
 	}

main.go

@@ -22,6 +22,7 @@ import (
 	"github.com/newscred/webhook-broker/dispatcher"
 	"github.com/newscred/webhook-broker/storage"
 	"github.com/newscred/webhook-broker/storage/data"
+	"github.com/newscred/webhook-broker/utils"
 	lumberjack "gopkg.in/natefinch/lumberjack.v2"
 )
 
@@ -229,7 +230,7 @@ func startWebhookBroker(inConfig *config.CLIConfig) {
 			log.Print("Restarting")
 			setHasConfigChange(true)
 		}
-		syscall.Kill(pid, syscall.SIGINT)
+		utils.NewProcessKiller().Kill(pid, syscall.SIGINT)
 	})
 	for hasConfigChange {
 		setHasConfigChange(false)

utils/process_killer.go

@@ -0,0 +1,12 @@
+package utils
+
+import "syscall"
+
+// ProcessKiller interface for killing a process
+type ProcessKiller interface {
+	Kill(PID int, signal syscall.Signal) error
+}
+
+func NewProcessKiller() ProcessKiller {
+	return &DefaultProcessKiller{}
+}

utils/process_killer_unix.go

@@ -0,0 +1,25 @@
+//go:build linux || darwin
+
+package utils
+
+import (
+	"os"
+	"syscall"
+)
+
+// DefaultProcessKiller is a default implementation of ProcessKiller interface
+type DefaultProcessKiller struct{}
+
+func (pk *DefaultProcessKiller) Kill(pid int, signal syscall.Signal) error {
+	_, err := os.FindProcess(pid)
+	if err != nil {
+		return err
+	}
+
+	err = syscall.Kill(pid, syscall.SIGINT)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

utils/process_killer_windows.go

@@ -0,0 +1,15 @@
+//go:build windows
+
+package utils
+
+import (
+	"syscall"
+)
+
+// DefaultProcessKiller is a default implementation of ProcessKiller interface
+type DefaultProcessKiller struct {
+}
+
+func (pk *DefaultProcessKiller) Kill(pid int, signal syscall.Signal) error {
+	return nil
+}