container kill support

Signed-off-by: rajasec <rajasec79@gmail.com>

README.md

@@ -237,3 +237,11 @@ WorkingDirectory=/containers/minecraftbuild
 [Install]
 WantedBy=multi-user.target
 ```
+##Usage:
+runc --id=runc kill <arguments>
+##Arguments can be signal number or signal name in string 
+
+##Example
+runc --id=runc kill TERM
+runc --id=runc kill 15
+##if the shell is interactive, few signals can not be forwarded. /bin/sh can not forward the signal

kill.go

@@ -0,0 +1,53 @@
+// +build linux
+
+package main
+
+import (
+	"fmt"
+	"github.com/codegangsta/cli"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+var killCommand = cli.Command{
+	Name:  "kill",
+	Usage: "kill a container",
+	Action: func(context *cli.Context) {
+		container, err := getContainer(context)
+		if err != nil {
+			fatal(fmt.Errorf("%s", err))
+		}
+		sigStr := context.Args().First()
+		state, err := container.Status()
+		if err != nil {
+			fatal(fmt.Errorf("Container not running %d", state))
+			// return here
+		}
+		var sig uint64
+		sigN, err := strconv.ParseUint(sigStr, 10, 5)
+		if err != nil {
+			//The signal is not a number, treat it as a string (either like
+			//KILL" or like "SIGKILL")
+			syscallSig, ok := SignalMap[strings.TrimPrefix(sigStr, "SIG")]
+			if !ok {
+				fatal(fmt.Errorf("Invalid Signal: %s", sigStr))
+			}
+			sig = uint64(syscallSig)
+			errVal := container.Signal(syscall.Signal(sig))
+			if errVal != nil {
+				fatal(fmt.Errorf("%s", errVal))
+			}
+		} else {
+			sig = sigN
+			errVar := container.Signal(syscall.Signal(sig))
+			if errVar != nil {
+				fatal(fmt.Errorf("%s", errVar))
+			}
+
+		}
+		if sig == 0 {
+			fatal(fmt.Errorf("Invalid signal: %s", sigStr))
+		}
+	},
+}

main.go

@@ -55,6 +55,7 @@ func main() {
 		checkpointCommand,
 		eventsCommand,
 		restoreCommand,
+		killCommand,
 		specCommand,
 	}
 	app.Before = func(context *cli.Context) error {

signal_linux.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"syscall"
+)
+
+var SignalMap = map[string]syscall.Signal{
+	"ABRT":   syscall.SIGABRT,
+	"ALRM":   syscall.SIGALRM,
+	"BUS":    syscall.SIGBUS,
+	"CHLD":   syscall.SIGCHLD,
+	"CLD":    syscall.SIGCLD,
+	"CONT":   syscall.SIGCONT,
+	"FPE":    syscall.SIGFPE,
+	"HUP":    syscall.SIGHUP,
+	"ILL":    syscall.SIGILL,
+	"INT":    syscall.SIGINT,
+	"IO":     syscall.SIGIO,
+	"IOT":    syscall.SIGIOT,
+	"KILL":   syscall.SIGKILL,
+	"PIPE":   syscall.SIGPIPE,
+	"POLL":   syscall.SIGPOLL,
+	"PROF":   syscall.SIGPROF,
+	"PWR":    syscall.SIGPWR,
+	"QUIT":   syscall.SIGQUIT,
+	"SEGV":   syscall.SIGSEGV,
+	"STKFLT": syscall.SIGSTKFLT,
+	"STOP":   syscall.SIGSTOP,
+	"SYS":    syscall.SIGSYS,
+	"TERM":   syscall.SIGTERM,
+	"TRAP":   syscall.SIGTRAP,
+	"TSTP":   syscall.SIGTSTP,
+	"TTIN":   syscall.SIGTTIN,
+	"TTOU":   syscall.SIGTTOU,
+	"UNUSED": syscall.SIGUNUSED,
+	"URG":    syscall.SIGURG,
+	"USR1":   syscall.SIGUSR1,
+	"USR2":   syscall.SIGUSR2,
+	"VTALRM": syscall.SIGVTALRM,
+	"WINCH":  syscall.SIGWINCH,
+	"XCPU":   syscall.SIGXCPU,
+	"XFSZ":   syscall.SIGXFSZ,
+}