ctr: move events command

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

cmd/ctr/commands/events/events.go

@@ -0,0 +1,58 @@
+package events
+
+import (
+	"encoding/json"
+	"fmt"
+
+	eventsapi "github.com/containerd/containerd/api/services/events/v1"
+	"github.com/containerd/containerd/cmd/ctr/commands"
+	"github.com/containerd/typeurl"
+	"github.com/urfave/cli"
+)
+
+// Command is the cli command for displaying containerd events
+var Command = cli.Command{
+	Name:  "events",
+	Usage: "display containerd events",
+	Action: func(context *cli.Context) error {
+		client, ctx, cancel, err := commands.NewClient(context)
+		if err != nil {
+			return err
+		}
+		defer cancel()
+		eventsClient := client.EventService()
+		events, err := eventsClient.Subscribe(ctx, &eventsapi.SubscribeRequest{
+			Filters: context.Args(),
+		})
+		if err != nil {
+			return err
+		}
+		for {
+			e, err := events.Recv()
+			if err != nil {
+				return err
+			}
+
+			var out []byte
+			if e.Event != nil {
+				v, err := typeurl.UnmarshalAny(e.Event)
+				if err != nil {
+					return err
+				}
+				out, err = json.Marshal(v)
+				if err != nil {
+					return err
+				}
+			}
+
+			if _, err := fmt.Println(
+				e.Timestamp,
+				e.Namespace,
+				e.Topic,
+				string(out),
+			); err != nil {
+				return err
+			}
+		}
+	},
+}