Implement hook timeouts

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

libcontainer/configs/config.go

@@ -3,7 +3,9 @@ package configs
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"os/exec"
+	"time"
 
 	"github.com/Sirupsen/logrus"
 )
@@ -274,10 +276,11 @@ func (f FuncHook) Run(s HookState) error {
 }
 
 type Command struct {
-	Path string   `json:"path"`
-	Args []string `json:"args"`
-	Env  []string `json:"env"`
-	Dir  string   `json:"dir"`
+	Path    string         `json:"path"`
+	Args    []string       `json:"args"`
+	Env     []string       `json:"env"`
+	Dir     string         `json:"dir"`
+	Timeout *time.Duration `json:"timeout"`
 }
 
 // NewCommandHooks will execute the provided command when the hook is run.
@@ -302,5 +305,19 @@ func (c Command) Run(s HookState) error {
 		Env:   c.Env,
 		Stdin: bytes.NewReader(b),
 	}
-	return cmd.Run()
+	errC := make(chan error, 1)
+	go func() {
+		errC <- cmd.Run()
+	}()
+	if c.Timeout != nil {
+		select {
+		case err := <-errC:
+			return err
+		case <-time.After(*c.Timeout):
+			cmd.Process.Kill()
+			cmd.Wait()
+			return fmt.Errorf("hook ran past specified timeout of %.1fs", c.Timeout.Seconds())
+		}
+	}
+	return <-errC
 }

libcontainer/specconv/spec_linux.go

@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"strings"
 	"syscall"
+	"time"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
 	"github.com/opencontainers/runc/libcontainer/configs"
@@ -719,27 +720,28 @@ func setupSeccomp(config *specs.Seccomp) (*configs.Seccomp, error) {
 func createHooks(rspec *specs.Spec, config *configs.Config) {
 	config.Hooks = &configs.Hooks{}
 	for _, h := range rspec.Hooks.Prestart {
-		cmd := configs.Command{
-			Path: h.Path,
-			Args: h.Args,
-			Env:  h.Env,
-		}
+		cmd := createCommandHook(h)
 		config.Hooks.Prestart = append(config.Hooks.Prestart, configs.NewCommandHook(cmd))
 	}
 	for _, h := range rspec.Hooks.Poststart {
-		cmd := configs.Command{
-			Path: h.Path,
-			Args: h.Args,
-			Env:  h.Env,
-		}
+		cmd := createCommandHook(h)
 		config.Hooks.Poststart = append(config.Hooks.Poststart, configs.NewCommandHook(cmd))
 	}
 	for _, h := range rspec.Hooks.Poststop {
-		cmd := configs.Command{
-			Path: h.Path,
-			Args: h.Args,
-			Env:  h.Env,
-		}
+		cmd := createCommandHook(h)
 		config.Hooks.Poststop = append(config.Hooks.Poststop, configs.NewCommandHook(cmd))
 	}
 }
+
+func createCommandHook(h specs.Hook) configs.Command {
+	cmd := configs.Command{
+		Path: h.Path,
+		Args: h.Args,
+		Env:  h.Env,
+	}
+	if h.Timeout != nil {
+		d := time.Duration(*h.Timeout) * time.Second
+		cmd.Timeout = &d
+	}
+	return cmd
+}