Engine: new command 'kill' sends a signal to a running container

api.go

@@ -150,19 +150,11 @@ func postContainersKill(srv *Server, version float64, w http.ResponseWriter, r *
 	if err := parseForm(r); err != nil {
 		return err
 	}
-	name := vars["name"]
-
-	signal := 0
-	if r != nil {
-		if s := r.Form.Get("signal"); s != "" {
-			s, err := strconv.Atoi(s)
-			if err != nil {
-				return err
+	job := srv.Eng.Job("kill", vars["name"])
+	if sig := r.Form.Get("signal"); sig != "" {
+		job.Args = append(job.Args, sig)
 	}
-			signal = s
-		}
-	}
-	if err := srv.ContainerKill(name, signal); err != nil {
+	if err := job.Run(); err != nil {
 		return err
 	}
 	w.WriteHeader(http.StatusNoContent)

server.go

@@ -23,6 +23,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
+	"strconv"
 	"sync"
 	"syscall"
 	"time"
@@ -78,6 +79,9 @@ func jobInitApi(job *engine.Job) engine.Status {
 		job.Error(err)
 		return engine.StatusErr
 	}
+	if err := job.Eng.Register("kill", srv.ContainerKill); err != nil {
+		return err.Error()
+	}
 	if err := job.Eng.Register("serveapi", srv.ListenAndServe); err != nil {
 		job.Error(err)
 		return engine.StatusErr
@@ -169,25 +173,38 @@ func (srv *Server) versionInfos() []utils.VersionInfo {
 // If no signal is given (sig 0), then Kill with SIGKILL and wait
 // for the container to exit.
 // If a signal is given, then just send it to the container and return.
-func (srv *Server) ContainerKill(name string, sig int) error {
+func (srv *Server) ContainerKill(job *engine.Job) string {
+	if n := len(job.Args); n < 1 || n > 2 {
+		return fmt.Sprintf("Usage: %s CONTAINER [SIGNAL]", job.Name)
+	}
+	name := job.Args[0]
+	var sig uint64
+	if len(job.Args) == 2 && job.Args[1] != "" {
+		var err error
+		// The largest legal signal is 31, so let's parse on 5 bits
+		sig, err = strconv.ParseUint(job.Args[1], 10, 5)
+		if err != nil {
+			return fmt.Sprintf("Invalid signal: %s", job.Args[1])
+		}
+	}
 	if container := srv.runtime.Get(name); container != nil {
 		// If no signal is passed, perform regular Kill (SIGKILL + wait())
 		if sig == 0 {
 			if err := container.Kill(); err != nil {
-				return fmt.Errorf("Cannot kill container %s: %s", name, err)
+				return fmt.Sprintf("Cannot kill container %s: %s", name, err)
 			}
 			srv.LogEvent("kill", container.ID, srv.runtime.repositories.ImageName(container.Image))
 		} else {
 			// Otherwise, just send the requested signal
-			if err := container.kill(sig); err != nil {
-				return fmt.Errorf("Cannot kill container %s: %s", name, err)
+			if err := container.kill(int(sig)); err != nil {
+				return fmt.Sprintf("Cannot kill container %s: %s", name, err)
 			}
 			// FIXME: Add event for signals
 		}
 	} else {
-		return fmt.Errorf("No such container: %s", name)
+		return fmt.Sprintf("No such container: %s", name)
 	}
-	return nil
+	return "0"
 }
 
 func (srv *Server) ContainerExport(name string, out io.Writer) error {