first commit

main.go

@@ -0,0 +1,210 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+type Service struct {
+	CMD  string   `json:"cmd"`
+	Args []string `json:"args"`
+	PWD  string   `json:"pwd"`
+
+	cmd *exec.Cmd
+}
+
+type Config struct {
+	Services []*Service `json:"services"`
+}
+
+func printErr(err error) {
+	fmt.Fprintf(os.Stderr, "[qini] Err: %s\n", err.Error())
+}
+
+func printInfo(info string) {
+	fmt.Fprintf(os.Stderr, "[qini] Inf: %s\n", info)
+}
+
+var verbose bool
+
+func debug(s string, a ...any) {
+	if verbose {
+		fmt.Fprintf(os.Stderr, "[qini] debug: %s\n", fmt.Sprintf(s, a...))
+	}
+}
+
+func stopAllServices(services []*Service) {
+	for _, s := range services {
+		if s.cmd.Process == nil {
+			continue
+		}
+
+		debug("send SIGINT to [%s]", s.CMD)
+		s.cmd.Process.Signal(syscall.SIGINT)
+
+		go func(s *Service) {
+			time.Sleep(15 * time.Second)
+			if s.cmd.Process != nil && s.cmd.ProcessState == nil {
+				debug("send SIGKILL to [%s]", s.CMD)
+				s.cmd.Process.Kill()
+			}
+		}(s)
+	}
+}
+
+func runServices(services []*Service) int {
+	if len(services) == 0 {
+		printInfo("no services in config")
+		return 1
+	}
+
+	var (
+		r *io.PipeReader
+		w *io.PipeWriter
+
+		lock sync.Mutex
+		once sync.Once
+		wg   sync.WaitGroup
+
+		exitCode int
+	)
+
+	lock.Lock()
+
+	for i, s := range services {
+		s.cmd = exec.Command(s.CMD, s.Args...)
+
+		s.cmd.SysProcAttr = &syscall.SysProcAttr{
+			Setsid: false,
+		}
+
+		if s.PWD != "" {
+			s.cmd.Dir = s.PWD
+		}
+
+		if r != nil {
+			s.cmd.Stdin = r
+		}
+
+		if i+1 < len(services) {
+			r, w = io.Pipe()
+			s.cmd.Stdout = w
+		} else {
+			s.cmd.Stdout = os.Stdout
+		}
+
+		wg.Add(1)
+		go func(w *io.PipeWriter) {
+			defer wg.Done()
+
+			defer func() {
+				if w != nil {
+					w.Close()
+				}
+
+				once.Do(func() {
+					lock.Lock()
+					defer lock.Unlock()
+
+					debug("stop all services")
+
+					stopAllServices(services)
+					exitCode = s.cmd.ProcessState.ExitCode()
+				})
+			}()
+
+			debug("run service [%s]", s.CMD)
+			err := s.cmd.Run()
+			if err != nil {
+				printErr(err)
+			}
+			debug("service [%s] done, err: [%v]", s.CMD, err)
+		}(w)
+	}
+
+	lock.Unlock()
+
+	debug("wait servises")
+	wg.Wait()
+	debug("all servises stoped")
+
+	return exitCode
+}
+
+func loadConfig(cfg *Config, configFile string) error {
+	f, err := os.Open(configFile)
+	if err != nil {
+		return err
+	}
+
+	defer f.Close()
+
+	return json.NewDecoder(f).Decode(cfg)
+}
+
+func forwardSignals(services []*Service) {
+	signals := []os.Signal{syscall.SIGTERM, syscall.SIGINT, syscall.SIGQUIT}
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, signals...)
+
+	for sig := range sigCh {
+		for _, s := range services {
+			if s.cmd.Process == nil {
+				continue
+			}
+
+			syscall.Kill(s.cmd.Process.Pid, (sig).(syscall.Signal))
+		}
+	}
+}
+
+func forwardSignals2(services []*Service) {
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGCHLD)
+
+	for _ = range sigCh {
+		printInfo("chld")
+		for _, c := range services {
+			if c.cmd.ProcessState != nil {
+
+			}
+		}
+	}
+}
+
+func main() {
+	verbose = true
+
+	err := unix.Prctl(unix.PR_SET_CHILD_SUBREAPER, 1, 0, 0, 0)
+	if err != nil {
+		printErr(err)
+	}
+
+	var configFile string
+	flag.StringVar(&configFile, "c", "./config.json", "JSON config file")
+	flag.Parse()
+
+	var cfg Config
+
+	err = loadConfig(&cfg, configFile)
+	if err != nil {
+		printErr(err)
+		os.Exit(1)
+	}
+
+	go forwardSignals(cfg.Services)
+	go forwardSignals2(cfg.Services)
+
+	exitCode := runServices(cfg.Services)
+	os.Exit(exitCode)
+}