Move shim protos into linux pkg

This moves the shim's API and protos out of the containerd services
package and into the linux runtime package. This is because the shim is
an implementation detail of the linux runtime that we have and it is not
a containerd user facing api.

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

cmd/containerd-shim/main_unix.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"runtime"
 	"strings"
 
 	"golang.org/x/sys/unix"
@@ -13,8 +14,8 @@ import (
 	"google.golang.org/grpc"
 
 	"github.com/Sirupsen/logrus"
-	shimapi "github.com/containerd/containerd/api/services/shim/v1"
 	"github.com/containerd/containerd/linux/shim"
+	shimapi "github.com/containerd/containerd/linux/shim/v1"
 	"github.com/containerd/containerd/reaper"
 	"github.com/containerd/containerd/version"
 	"github.com/urfave/cli"
@@ -66,7 +67,7 @@ func main() {
 			return err
 		}
 		server := grpc.NewServer()
-		sv, err := shim.New(path, context.GlobalString("namespace"))
+		sv, err := shim.NewService(path, context.GlobalString("namespace"))
 		if err != nil {
 			return err
 		}
@@ -114,7 +115,24 @@ func handleSignals(signals chan os.Signal, server *grpc.Server) error {
 			// i.e. machine reboot
 			server.Stop()
 			return nil
+		case unix.SIGUSR1:
+			dumpStacks()
 		}
 	}
 	return nil
 }
+
+func dumpStacks() {
+	var (
+		buf       []byte
+		stackSize int
+	)
+	bufferLen := 16384
+	for stackSize == len(buf) {
+		buf = make([]byte, bufferLen)
+		stackSize = runtime.Stack(buf, true)
+		bufferLen *= 2
+	}
+	buf = buf[:stackSize]
+	logrus.Infof("=== BEGIN goroutine stack dump ===\n%s\n=== END goroutine stack dump ===", buf)
+}