Update shim for exec

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

runtime/runtime.go

@@ -1,6 +1,9 @@
 package runtime
 
-import "errors"
+import (
+	"errors"
+	"time"
+)
 
 var (
 	ErrNotChildProcess       = errors.New("containerd: not a child process for container")
@@ -14,3 +17,46 @@ var (
 
 	errNotImplemented = errors.New("containerd: not implemented")
 )
+
+const (
+	ExitFile       = "exit"
+	ExitStatusFile = "exitStatus"
+	StateFile      = "state.json"
+	InitProcessID  = "init"
+)
+
+type State string
+
+const (
+	Paused  = State("paused")
+	Running = State("running")
+)
+
+type state struct {
+	Bundle string `json:"bundle"`
+}
+
+type Stat struct {
+	// Timestamp is the time that the statistics where collected
+	Timestamp time.Time
+	// Data is the raw stats
+	// TODO: it is currently an interface because we don't know what type of exec drivers
+	// we will have or what the structure should look like at the moment os the containers
+	// can return what they want and we could marshal to json or whatever.
+	Data interface{}
+}
+
+type Checkpoint struct {
+	// Timestamp is the time that checkpoint happened
+	Timestamp time.Time
+	// Name is the name of the checkpoint
+	Name string
+	// Tcp checkpoints open tcp connections
+	Tcp bool
+	// UnixSockets persists unix sockets in the checkpoint
+	UnixSockets bool
+	// Shell persists tty sessions in the checkpoint
+	Shell bool
+	// Exit exits the container after the checkpoint is finished
+	Exit bool
+}