package runner import ( "fmt" "os" "os/exec" "path/filepath" "strings" "time" "git.rootprojects.org/root/go-serviceman/service" ) // Filled in on init by runner_windows.go var shellArgs = []string{} // Notes on spawning a child process // https://groups.google.com/forum/#!topic/golang-nuts/shST-SDqIp4 func Run(conf *service.Service) { originalBackoff := 1 * time.Second maxBackoff := 1 * time.Minute threshold := 5 * time.Second backoff := originalBackoff failures := 0 logfile := filepath.Join(conf.Logdir, conf.Name+".log") binpath := conf.Exec args := []string{} if "" != conf.Interpreter { binpath = conf.Interpreter args = append(args, conf.Exec) } args = append(args, conf.Argv...) if !conf.System && 0 != len(shellArgs) { nargs := append(shellArgs[1:], binpath) args = append(nargs, args...) binpath = shellArgs[0] } for { // setup the log lf, err := os.OpenFile(logfile, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644) if nil != err { fmt.Fprintf(os.Stderr, "[%s] Could not open log file %q\n", time.Now(), logfile) lf = os.Stderr } else { defer lf.Close() } start := time.Now() cmd := exec.Command(binpath, args...) fmt.Fprintf(lf, "[%s] Starting %q %s \n", time.Now(), binpath, strings.Join(args, " ")) cmd.Stdin = nil cmd.Stdout = lf cmd.Stderr = lf if "" != conf.Workdir { cmd.Dir = conf.Workdir } err = cmd.Start() if nil != err { fmt.Fprintf(lf, "[%s] Could not start %q process: %s\n", time.Now(), conf.Name, err) } else { err = cmd.Wait() if nil != err { fmt.Fprintf(lf, "[%s] Process %q failed with error: %s\n", time.Now(), conf.Name, err) } else { fmt.Fprintf(lf, "[%s] Process %q exited cleanly\n", time.Now(), conf.Name) } } // if this is a oneshot... so it is if !conf.Restart { fmt.Fprintf(lf, "Not restarting %q because `restart` set to `false`\n", conf.Name) break } end := time.Now() if end.Sub(start) > threshold { backoff = originalBackoff failures = 0 } else { failures += 1 fmt.Fprintf(lf, "Waiting %s to restart %q (%d consequtive immediate exits)\n", backoff, conf.Name, failures) time.Sleep(backoff) backoff *= 2 if backoff > maxBackoff { backoff = maxBackoff } } } }