ctr: move signals to commands package

Signed-off-by: Jess Valarezo <valarezo.jessica@gmail.com>

cmd/ctr/attach.go

@@ -55,8 +55,8 @@ var taskAttachCommand = cli.Command{
 				logrus.WithError(err).Error("console resize")
 			}
 		} else {
-			sigc := forwardAllSignals(ctx, task)
+			sigc := commands.ForwardAllSignals(ctx, task)
-			defer stopCatch(sigc)
+			defer commands.StopCatch(sigc)
 		}
 
 		ec := <-statusC

cmd/ctr/commands/signals.go

@@ -0,0 +1,59 @@
+package commands
+
+import (
+	gocontext "context"
+	"fmt"
+	"os"
+	"os/signal"
+	"strconv"
+	"strings"
+	"syscall"
+
+	"github.com/containerd/containerd"
+	"github.com/sirupsen/logrus"
+)
+
+type killer interface {
+	Kill(gocontext.Context, syscall.Signal, ...containerd.KillOpts) error
+}
+
+// ForwardAllSignals forwards signals
+func ForwardAllSignals(ctx gocontext.Context, task killer) chan os.Signal {
+	sigc := make(chan os.Signal, 128)
+	signal.Notify(sigc)
+	go func() {
+		for s := range sigc {
+			logrus.Debug("forwarding signal ", s)
+			if err := task.Kill(ctx, s.(syscall.Signal)); err != nil {
+				logrus.WithError(err).Errorf("forward signal %s", s)
+			}
+		}
+	}()
+	return sigc
+}
+
+// StopCatch stops and closes a channel
+func StopCatch(sigc chan os.Signal) {
+	signal.Stop(sigc)
+	close(sigc)
+}
+
+// ParseSignal parses a given string into a syscall.Signal
+// it checks that the signal exists in the platform-appropriate signalMap
+func ParseSignal(rawSignal string) (syscall.Signal, error) {
+	s, err := strconv.Atoi(rawSignal)
+	if err == nil {
+		sig := syscall.Signal(s)
+		for _, msig := range signalMap {
+			if sig == msig {
+				return sig, nil
+			}
+		}
+		return -1, fmt.Errorf("unknown signal %q", rawSignal)
+	}
+	signal, ok := signalMap[strings.TrimPrefix(strings.ToUpper(rawSignal), "SIG")]
+	if !ok {
+		return -1, fmt.Errorf("unknown signal %q", rawSignal)
+	}
+	return signal, nil
+}

cmd/ctr/commands/signals_linux.go

@@ -1,4 +1,4 @@
-package main
+package commands
 
 import (
 	"syscall"

cmd/ctr/commands/signals_unix.go

@@ -1,6 +1,6 @@
 // +build darwin freebsd solaris
 
-package main
+package commands
 
 import (
 	"syscall"

cmd/ctr/commands/signals_windows.go

@@ -0,0 +1,23 @@
+package commands
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/windows"
+)
+
+var signalMap = map[string]syscall.Signal{
+	"HUP":    syscall.Signal(windows.SIGHUP),
+	"INT":    syscall.Signal(windows.SIGINT),
+	"QUIT":   syscall.Signal(windows.SIGQUIT),
+	"SIGILL": syscall.Signal(windows.SIGILL),
+	"TRAP":   syscall.Signal(windows.SIGTRAP),
+	"ABRT":   syscall.Signal(windows.SIGABRT),
+	"BUS":    syscall.Signal(windows.SIGBUS),
+	"FPE":    syscall.Signal(windows.SIGFPE),
+	"KILL":   syscall.Signal(windows.SIGKILL),
+	"SEGV":   syscall.Signal(windows.SIGSEGV),
+	"PIPE":   syscall.Signal(windows.SIGPIPE),
+	"ALRM":   syscall.Signal(windows.SIGALRM),
+	"TERM":   syscall.Signal(windows.SIGTERM),
+}

cmd/ctr/exec.go

@@ -10,6 +10,7 @@ import (
 	"github.com/urfave/cli"
 )
 
+//TODO:(jessvalarezo) exec-id is optional here, update to required arg
 var taskExecCommand = cli.Command{
 	Name:      "exec",
 	Usage:     "execute additional processes in an existing container",
@@ -87,8 +88,8 @@ var taskExecCommand = cli.Command{
 				logrus.WithError(err).Error("console resize")
 			}
 		} else {
-			sigc := forwardAllSignals(ctx, process)
+			sigc := commands.ForwardAllSignals(ctx, process)
-			defer stopCatch(sigc)
+			defer commands.StopCatch(sigc)
 		}
 
 		if err := process.Start(ctx); err != nil {

cmd/ctr/kill.go

@@ -6,6 +6,8 @@ import (
 	"github.com/urfave/cli"
 )
 
+// TODO:(jessvalarezo) the pid flag is not used here
+// update to be able to signal given pid
 var taskKillCommand = cli.Command{
 	Name:      "kill",
 	Usage:     "signal a container (default: SIGTERM)",
@@ -31,7 +33,7 @@ var taskKillCommand = cli.Command{
 		if id == "" {
 			return errors.New("container id must be provided")
 		}
-		signal, err := parseSignal(context.String("signal"))
+		signal, err := commands.ParseSignal(context.String("signal"))
 		if err != nil {
 			return err
 		}

cmd/ctr/run.go

@@ -4,7 +4,6 @@ import (
 	gocontext "context"
 	"fmt"
 	"runtime"
-	"syscall"
 
 	"github.com/containerd/console"
 	"github.com/containerd/containerd"
@@ -20,10 +19,6 @@ type resizer interface {
 	Resize(ctx gocontext.Context, w, h uint32) error
 }
 
-type killer interface {
-	Kill(gocontext.Context, syscall.Signal, ...containerd.KillOpts) error
-}
-
 func withEnv(context *cli.Context) containerd.SpecOpts {
 	return func(_ gocontext.Context, _ *containerd.Client, _ *containers.Container, s *specs.Spec) error {
 		env := context.StringSlice("env")
@@ -160,8 +155,8 @@ var runCommand = cli.Command{
 				logrus.WithError(err).Error("console resize")
 			}
 		} else {
-			sigc := forwardAllSignals(ctx, task)
+			sigc := commands.ForwardAllSignals(ctx, task)
-			defer stopCatch(sigc)
+			defer commands.StopCatch(sigc)
 		}
 		status := <-statusC
 		code, _, err := status.Result()

cmd/ctr/start.go

@@ -70,8 +70,8 @@ var taskStartCommand = cli.Command{
 				logrus.WithError(err).Error("console resize")
 			}
 		} else {
-			sigc := forwardAllSignals(ctx, task)
+			sigc := commands.ForwardAllSignals(ctx, task)
-			defer stopCatch(sigc)
+			defer commands.StopCatch(sigc)
 		}
 
 		status := <-statusC

cmd/ctr/utils.go

@@ -8,11 +8,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
-	"os"
-	"os/signal"
-	"strconv"
 	"strings"
-	"syscall"
 	"time"
 
 	"github.com/containerd/console"
@@ -20,7 +16,6 @@ import (
 	"github.com/containerd/containerd/remotes/docker"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 )
 
@@ -95,43 +90,6 @@ func getResolver(ctx gocontext.Context, clicontext *cli.Context) (remotes.Resolv
 	return docker.NewResolver(options), nil
 }
 
-func forwardAllSignals(ctx gocontext.Context, task killer) chan os.Signal {
-	sigc := make(chan os.Signal, 128)
-	signal.Notify(sigc)
-	go func() {
-		for s := range sigc {
-			logrus.Debug("forwarding signal ", s)
-			if err := task.Kill(ctx, s.(syscall.Signal)); err != nil {
-				logrus.WithError(err).Errorf("forward signal %s", s)
-			}
-		}
-	}()
-	return sigc
-}
-
-func parseSignal(rawSignal string) (syscall.Signal, error) {
-	s, err := strconv.Atoi(rawSignal)
-	if err == nil {
-		sig := syscall.Signal(s)
-		for _, msig := range signalMap {
-			if sig == msig {
-				return sig, nil
-			}
-		}
-		return -1, fmt.Errorf("unknown signal %q", rawSignal)
-	}
-	signal, ok := signalMap[strings.TrimPrefix(strings.ToUpper(rawSignal), "SIG")]
-	if !ok {
-		return -1, fmt.Errorf("unknown signal %q", rawSignal)
-	}
-	return signal, nil
-}
-
-func stopCatch(sigc chan os.Signal) {
-	signal.Stop(sigc)
-	close(sigc)
-}
-
 // parseMountFlag parses a mount string in the form "type=foo,source=/path,destination=/target,options=rbind:rw"
 func parseMountFlag(m string) (specs.Mount, error) {
 	mount := specs.Mount{}

cmd/ctr/utils_windows.go

@@ -5,12 +5,10 @@ import (
 	"net"
 	"os"
 	"sync"
-	"syscall"
 
 	"github.com/Microsoft/go-winio"
 	clog "github.com/containerd/containerd/log"
 	"github.com/pkg/errors"
-	"golang.org/x/sys/windows"
 )
 
 func prepareStdio(stdin, stdout, stderr string, console bool) (*sync.WaitGroup, error) {
@@ -91,19 +89,3 @@ func prepareStdio(stdin, stdout, stderr string, console bool) (*sync.WaitGroup,
 
 	return &wg, nil
 }
-
-var signalMap = map[string]syscall.Signal{
-	"HUP":    syscall.Signal(windows.SIGHUP),
-	"INT":    syscall.Signal(windows.SIGINT),
-	"QUIT":   syscall.Signal(windows.SIGQUIT),
-	"SIGILL": syscall.Signal(windows.SIGILL),
-	"TRAP":   syscall.Signal(windows.SIGTRAP),
-	"ABRT":   syscall.Signal(windows.SIGABRT),
-	"BUS":    syscall.Signal(windows.SIGBUS),
-	"FPE":    syscall.Signal(windows.SIGFPE),
-	"KILL":   syscall.Signal(windows.SIGKILL),
-	"SEGV":   syscall.Signal(windows.SIGSEGV),
-	"PIPE":   syscall.Signal(windows.SIGPIPE),
-	"ALRM":   syscall.Signal(windows.SIGALRM),
-	"TERM":   syscall.Signal(windows.SIGTERM),
-}