feat: create standalone native fnOS repository

app-src/internal/nginx/pid_unix.go

@@ -0,0 +1,24 @@
+//go:build linux || darwin || freebsd
+
+package nginx
+
+import (
+	"os"
+	"syscall"
+)
+
+func reloadProcess(pid int) error {
+	return syscall.Kill(pid, syscall.SIGHUP)
+}
+
+func terminateProcess(pid int, sig syscall.Signal) error {
+	return syscall.Kill(pid, sig)
+}
+
+func isPIDAlive(pid int) bool {
+	proc, err := os.FindProcess(pid)
+	if err != nil {
+		return false
+	}
+	return proc.Signal(syscall.Signal(0)) == nil
+}