Complete refactor to new grpc control plane and only http proxy for carts (#4)

Co-authored-by: matst80 <mats.tornberg@gmail.com>
Reviewed-on: https://git.tornberg.me/mats/go-cart-actor/pulls/4
Co-authored-by: Mats Törnberg <mats@tornberg.me>
Co-committed-by: Mats Törnberg <mats@tornberg.me>

pkg/actor/grpc_server.go

@@ -0,0 +1,119 @@
+package actor
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"time"
+
+	messages "git.tornberg.me/go-cart-actor/pkg/messages"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/reflection"
+)
+
+// ControlServer implements the ControlPlane gRPC services.
+// It delegates to a grain pool and cluster operations to a synced pool.
+type ControlServer[V any] struct {
+	messages.UnimplementedControlPlaneServer
+
+	pool GrainPool[V]
+}
+
+func (s *ControlServer[V]) AnnounceOwnership(ctx context.Context, req *messages.OwnershipAnnounce) (*messages.OwnerChangeAck, error) {
+	err := s.pool.HandleOwnershipChange(req.Host, req.Ids)
+	if err != nil {
+		return &messages.OwnerChangeAck{
+			Accepted: false,
+			Message:  "owner change failed",
+		}, err
+	}
+
+	log.Printf("Ack count: %d", len(req.Ids))
+	return &messages.OwnerChangeAck{
+		Accepted: true,
+		Message:  "ownership announced",
+	}, nil
+}
+
+func (s *ControlServer[V]) AnnounceExpiry(ctx context.Context, req *messages.ExpiryAnnounce) (*messages.OwnerChangeAck, error) {
+	err := s.pool.HandleRemoteExpiry(req.Host, req.Ids)
+	return &messages.OwnerChangeAck{
+		Accepted: err == nil,
+		Message:  "expiry acknowledged",
+	}, nil
+}
+
+// ControlPlane: Ping
+func (s *ControlServer[V]) Ping(ctx context.Context, _ *messages.Empty) (*messages.PingReply, error) {
+	// log.Printf("got ping")
+	return &messages.PingReply{
+		Host:     s.pool.Hostname(),
+		UnixTime: time.Now().Unix(),
+	}, nil
+}
+
+// ControlPlane: Negotiate (merge host views)
+func (s *ControlServer[V]) Negotiate(ctx context.Context, req *messages.NegotiateRequest) (*messages.NegotiateReply, error) {
+
+	s.pool.Negotiate(req.KnownHosts)
+	return &messages.NegotiateReply{Hosts: req.GetKnownHosts()}, nil
+}
+
+// ControlPlane: GetCartIds (locally owned carts only)
+func (s *ControlServer[V]) GetLocalActorIds(ctx context.Context, _ *messages.Empty) (*messages.ActorIdsReply, error) {
+	return &messages.ActorIdsReply{Ids: s.pool.GetLocalIds()}, nil
+}
+
+// ControlPlane: Closing (peer shutdown notification)
+func (s *ControlServer[V]) Closing(ctx context.Context, req *messages.ClosingNotice) (*messages.OwnerChangeAck, error) {
+	if req.GetHost() != "" {
+		s.pool.RemoveHost(req.GetHost())
+	}
+	return &messages.OwnerChangeAck{
+		Accepted: true,
+		Message:  "removed host",
+	}, nil
+}
+
+type ServerConfig struct {
+	Addr    string
+	Options []grpc.ServerOption
+}
+
+func NewServerConfig(addr string, options ...grpc.ServerOption) ServerConfig {
+	return ServerConfig{
+		Addr:    addr,
+		Options: options,
+	}
+}
+
+func DefaultServerConfig() ServerConfig {
+	return NewServerConfig(":1337")
+}
+
+// StartGRPCServer configures and starts the unified gRPC server on the given address.
+// It registers both the CartActor and ControlPlane services.
+func NewControlServer[V any](config ServerConfig, pool GrainPool[V]) (*grpc.Server, error) {
+	lis, err := net.Listen("tcp", config.Addr)
+	if err != nil {
+		return nil, fmt.Errorf("failed to listen: %w", err)
+	}
+
+	grpcServer := grpc.NewServer(config.Options...)
+	server := &ControlServer[V]{
+		pool: pool,
+	}
+
+	messages.RegisterControlPlaneServer(grpcServer, server)
+	reflection.Register(grpcServer)
+
+	log.Printf("gRPC server listening as %s on %s", pool.Hostname(), config.Addr)
+	go func() {
+		if err := grpcServer.Serve(lis); err != nil {
+			log.Fatalf("failed to serve gRPC: %v", err)
+		}
+	}()
+
+	return grpcServer, nil
+}