runner: add ability to wait for a process to finish before moving on

README.md

@@ -49,6 +49,9 @@ types will halt and not restart.
 - signal (in process types): "SIGTERM", "term", or "15" terminates the process;
 "SIGKILL", "kill", or "9" kills the process. The default is "SIGKILL".
 
+- signalWait (in process types): duration to wait after sending the signal to
+the process.
+
 - sticky (in build process types): a sticky build is not interrupted when file
 changes are detected.
 

internal/procfile/procfile.go

@@ -59,6 +59,9 @@
 // process; "SIGKILL", "kill", or "9" kills the process. The default is
 // "SIGKILL".
 //
+// - signalWait (in process types): duration to wait after sending the signal to
+// the process.
+//
 // - sticky (in build process types): a sticky build is not interrupted when
 // file changes are detected.
 //
@@ -72,6 +75,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"time"
 
 	"cirello.io/runner/internal/runner"
 )
@@ -143,6 +147,14 @@ func Parse(r io.Reader) (*runner.Runner, error) {
 					proc.Signal = runner.ParseSignal(strings.TrimPrefix(part, "signal="))
 					continue
 				}
+				if strings.HasPrefix(part, "signalWait=") {
+					signalWait, err := time.ParseDuration(strings.TrimPrefix(part, "signalWait="))
+					if err != nil {
+						return rnr, err
+					}
+					proc.SignalWait = signalWait
+					continue
+				}
 				if strings.HasPrefix(part, "optional=") {
 					optional, err := strconv.ParseBool(strings.TrimPrefix(part, "optional="))
 					if err != nil {

internal/runner/cmd_others.go

@@ -18,24 +18,32 @@
 package runner
 
 import (
+	"context"
+	"fmt"
 	"os/exec"
 	"syscall"
+	"time"
 )
 
-func command(cmd string, signal Signal) (*exec.Cmd, func() error) {
-	c := exec.Command("sh", "-c", cmd)
+func command(ctx context.Context, cmd string, signal Signal, signalWait time.Duration) *exec.Cmd {
+	c := exec.CommandContext(ctx, "sh", "-c", cmd)
 	c.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
-	return c, func() error {
-		if c.Process == nil {
-			return nil
-		}
+	c.Cancel = func() error {
 		pgid := -c.Process.Pid
-		kill := syscall.SIGKILL
+		osSignal := syscall.SIGKILL
 		if signal == SignalTERM {
-			kill = syscall.SIGTERM
+			osSignal = syscall.SIGTERM
+		}
+		if err := c.Process.Signal(osSignal); err != nil {
+			return fmt.Errorf("cannot signal process: %w", err)
+		}
+		if err := syscall.Kill(pgid, osSignal); err != nil {
+			return fmt.Errorf("cannot signal process group: %w", err)
+		}
+		if signalWait > 0 {
+			time.Sleep(signalWait)
 		}
-		_ = c.Process.Signal(kill)
-		_ = syscall.Kill(pgid, kill)
 		return nil
 	}
+	return c
 }

internal/runner/cmd_windows.go

@@ -20,16 +20,9 @@ package runner
 import (
 	"context"
 	"os/exec"
+	"time"
 )
 
-func command(cmd string, signal Signal) (*exec.Cmd, func() error) {
-	ctx, cancel := context.WithCancel(context.Background())
-	c := exec.CommandContext(ctx, "cmd", "/c", cmd)
-	return c, func() error {
-		// Custom signal is not supported on Windows.
-		_ = signal
-		cancel()
-		_ = c.Wait()
-		return nil
-	}
+func command(ctx context.Context, cmd string, _ Signal, _ time.Duration) *exec.Cmd {
+	return exec.CommandContext(ctx, "cmd", "/c", cmd)
 }

internal/runner/runner.go

@@ -108,6 +108,10 @@ type ProcessType struct {
 	// Signal indicates how a process should be halted.
 	Signal Signal
 
+	// SignalWait indicates how long to wait for a process to be finished
+	// before releasing it.
+	SignalWait time.Duration
+
 	// Sticky processes are not interrupted by filesystem events.
 	Sticky bool
 
@@ -468,7 +472,7 @@ func (r *Runner) startProcess(ctx context.Context, sv *ProcessType, procCount, p
 		fmt.Fprintln(pw, "listening on", port)
 	}
 	fmt.Fprintln(pw)
-	c, stopCmd := command(cmd, sv.Signal)
+	c := command(ctx, cmd, sv.Signal, sv.SignalWait)
 	c.Dir = r.WorkDir
 
 	c.Env = os.Environ()
@@ -504,15 +508,6 @@ func (r *Runner) startProcess(ctx context.Context, sv *ProcessType, procCount, p
 	if sv.WaitFor != "" {
 		r.waitFor(ctx, pw, sv.WaitFor)
 	}
-	done := make(chan struct{})
-	go func() {
-		select {
-		case <-ctx.Done():
-			stopCmd()
-		case <-done:
-		}
-	}()
-	defer close(done)
 	if err := c.Run(); err != nil {
 		fmt.Fprintf(pw, "exec error %s: (%s) %v\n", procName, cmd, err)
 		return false

main.go

@@ -58,6 +58,9 @@ types will halt and not restart.
 - signal (in process types): "SIGTERM", "term", or "15" terminates the process;
 "SIGKILL", "kill", or "9" kills the process. The default is "SIGKILL".
 
+- signalWait (in process types): duration to wait after sending the signal to
+the process.
+
 - sticky (in build process types): a sticky build is not interrupted when file
 changes are detected.