Add publish subcommand for publishing events

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

cmd/containerd/main.go

@@ -73,6 +73,7 @@ func main() {
 	}
 	app.Commands = []cli.Command{
 		configCommand,
+		publishCommand,
 	}
 	app.Action = func(context *cli.Context) error {
 		var (

cmd/containerd/publish.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	gocontext "context"
+	"io"
+	"io/ioutil"
+	"net"
+	"os"
+	"time"
+
+	eventsapi "github.com/containerd/containerd/api/services/events/v1"
+	"github.com/containerd/containerd/dialer"
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/namespaces"
+	"github.com/gogo/protobuf/types"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+	"google.golang.org/grpc"
+)
+
+var publishCommand = cli.Command{
+	Name:  "publish",
+	Usage: "binary to publish events to containerd",
+	Flags: []cli.Flag{
+		cli.StringFlag{
+			Name:  "namespace",
+			Usage: "namespace to publish to",
+		},
+		cli.StringFlag{
+			Name:  "topic",
+			Usage: "topic of the event",
+		},
+	},
+	Action: func(context *cli.Context) error {
+		ctx := namespaces.WithNamespace(gocontext.Background(), context.String("namespace"))
+		topic := context.String("topic")
+		if topic == "" {
+			return errors.New("topic required to publish event")
+		}
+		payload, err := getEventPayload(os.Stdin)
+		if err != nil {
+			return err
+		}
+		client, err := connectEvents(context.GlobalString("address"))
+		if err != nil {
+			return err
+		}
+		if _, err := client.Publish(ctx, &eventsapi.PublishRequest{
+			Topic: topic,
+			Event: payload,
+		}); err != nil {
+			return errdefs.FromGRPC(err)
+		}
+		return nil
+	},
+}
+
+func getEventPayload(r io.Reader) (*types.Any, error) {
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	var any types.Any
+	if err := any.Unmarshal(data); err != nil {
+		return nil, err
+	}
+	return &any, nil
+}
+
+func connectEvents(address string) (eventsapi.EventsClient, error) {
+	conn, err := connect(address, dialer.Dialer)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to dial %q", address)
+	}
+	return eventsapi.NewEventsClient(conn), nil
+}
+
+func connect(address string, d func(string, time.Duration) (net.Conn, error)) (*grpc.ClientConn, error) {
+	gopts := []grpc.DialOption{
+		grpc.WithBlock(),
+		grpc.WithInsecure(),
+		grpc.WithTimeout(60 * time.Second),
+		grpc.WithDialer(d),
+		grpc.FailOnNonTempDialError(true),
+		grpc.WithBackoffMaxDelay(3 * time.Second),
+	}
+	conn, err := grpc.Dial(dialer.DialAddress(address), gopts...)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to dial %q", address)
+	}
+	return conn, nil
+}