Create scaffolding of ddl-simulator

Implement global server as control plane

Implement device to get their info from global server and connect each
others

pkg/device/client.go

@@ -0,0 +1,52 @@
+package device
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	pb "git.pengzhan.dev/ddp-simulator/proto"
+	"github.com/cenkalti/backoff/v4"
+	log "github.com/sirupsen/logrus"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+func (d *Device) RegisterClient() error {
+	conn, err := grpc.NewClient(fmt.Sprintf("%s:%d", d.ParentIP, d.ParentPort), grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		log.Fatalf("failed to connect to global server: %v", err)
+	}
+	defer conn.Close()
+
+	client := pb.NewDeviceClient(conn)
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	children := make([]string, 0)
+	for _, child := range d.Children {
+		children = append(children, child.ID)
+	}
+
+	_, err = client.Register(ctx, &pb.RegisterRequest{
+		Id:          d.ID,
+		Role:        d.Role,
+		Ip:          d.IP,
+		Port:        int32(d.Port),
+		ChildrenIds: children,
+		Capacity:    d.Capacity,
+	})
+	return err
+}
+
+func (d *Device) RegisterClientRetry(ctx context.Context, timeout time.Duration) error {
+	b := backoff.NewExponentialBackOff()
+	b.InitialInterval = 1 * time.Second
+	b.MaxElapsedTime = timeout
+
+	retryOp := func() error {
+		return d.RegisterClient()
+	}
+	err := backoff.Retry(retryOp, backoff.WithContext(b, ctx))
+	return err
+}