ctr: move signals to commands package

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

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

@@ -0,0 +1,44 @@
+package commands
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+var signalMap = map[string]syscall.Signal{
+	"ABRT":   unix.SIGABRT,
+	"ALRM":   unix.SIGALRM,
+	"BUS":    unix.SIGBUS,
+	"CHLD":   unix.SIGCHLD,
+	"CLD":    unix.SIGCLD,
+	"CONT":   unix.SIGCONT,
+	"FPE":    unix.SIGFPE,
+	"HUP":    unix.SIGHUP,
+	"ILL":    unix.SIGILL,
+	"INT":    unix.SIGINT,
+	"IO":     unix.SIGIO,
+	"IOT":    unix.SIGIOT,
+	"KILL":   unix.SIGKILL,
+	"PIPE":   unix.SIGPIPE,
+	"POLL":   unix.SIGPOLL,
+	"PROF":   unix.SIGPROF,
+	"PWR":    unix.SIGPWR,
+	"QUIT":   unix.SIGQUIT,
+	"SEGV":   unix.SIGSEGV,
+	"STKFLT": unix.SIGSTKFLT,
+	"STOP":   unix.SIGSTOP,
+	"SYS":    unix.SIGSYS,
+	"TERM":   unix.SIGTERM,
+	"TRAP":   unix.SIGTRAP,
+	"TSTP":   unix.SIGTSTP,
+	"TTIN":   unix.SIGTTIN,
+	"TTOU":   unix.SIGTTOU,
+	"URG":    unix.SIGURG,
+	"USR1":   unix.SIGUSR1,
+	"USR2":   unix.SIGUSR2,
+	"VTALRM": unix.SIGVTALRM,
+	"WINCH":  unix.SIGWINCH,
+	"XCPU":   unix.SIGXCPU,
+	"XFSZ":   unix.SIGXFSZ,
+}

cmd/ctr/commands/signals_unix.go

@@ -0,0 +1,42 @@
+// +build darwin freebsd solaris
+
+package commands
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+var signalMap = map[string]syscall.Signal{
+	"ABRT":   unix.SIGABRT,
+	"ALRM":   unix.SIGALRM,
+	"BUS":    unix.SIGBUS,
+	"CHLD":   unix.SIGCHLD,
+	"CONT":   unix.SIGCONT,
+	"FPE":    unix.SIGFPE,
+	"HUP":    unix.SIGHUP,
+	"ILL":    unix.SIGILL,
+	"INT":    unix.SIGINT,
+	"IO":     unix.SIGIO,
+	"IOT":    unix.SIGIOT,
+	"KILL":   unix.SIGKILL,
+	"PIPE":   unix.SIGPIPE,
+	"PROF":   unix.SIGPROF,
+	"QUIT":   unix.SIGQUIT,
+	"SEGV":   unix.SIGSEGV,
+	"STOP":   unix.SIGSTOP,
+	"SYS":    unix.SIGSYS,
+	"TERM":   unix.SIGTERM,
+	"TRAP":   unix.SIGTRAP,
+	"TSTP":   unix.SIGTSTP,
+	"TTIN":   unix.SIGTTIN,
+	"TTOU":   unix.SIGTTOU,
+	"URG":    unix.SIGURG,
+	"USR1":   unix.SIGUSR1,
+	"USR2":   unix.SIGUSR2,
+	"VTALRM": unix.SIGVTALRM,
+	"WINCH":  unix.SIGWINCH,
+	"XCPU":   unix.SIGXCPU,
+	"XFSZ":   unix.SIGXFSZ,
+}

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),
+}