✨ Broadcast event

pkg/internal/directory/command.go

@@ -0,0 +1,22 @@
+package directory
+
+const (
+	CommandMethodGet    = "get"
+	CommandMethodPut    = "put"
+	CommandMethodPatch  = "patch"
+	CommandMethodPost   = "post"
+	CommandMethodDelete = "delete"
+)
+
+type Command struct {
+	// The unique identifier of the command, different method command can hold the same command id
+	ID string `json:"id"`
+	// The method of the command, such as get, post, others; inspired by RESTful design
+	Method string `json:"method"`
+	// The tags of the command will be used to invoke the pre-command middlewares and post-command middlewares
+	Tags []string `json:"tags"`
+	// The implementation of the command, the handler is the service that will be invoked
+	Handler []*ServiceInstance `json:"handler"`
+
+	robinIndex uint
+}

pkg/internal/directory/command_mapping.go

@@ -0,0 +1,67 @@
+package directory
+
+import (
+	"git.solsynth.dev/hypernet/nexus/pkg/nex"
+	"github.com/rs/zerolog/log"
+	"github.com/samber/lo"
+	"strings"
+	"sync"
+)
+
+// In commands, we use the map and the mutex because it is usually read and only sometimes write
+var commandDirectory = make(map[string]*Command)
+var commandDirectoryMutex sync.Mutex
+
+func AddCommand(id, method string, tags []string, handler *ServiceInstance) {
+	commandDirectoryMutex.Lock()
+	defer commandDirectoryMutex.Unlock()
+
+	if tags == nil {
+		tags = make([]string, 0)
+	}
+
+	ky := nex.GetCommandKey(id, method)
+	if _, ok := commandDirectory[ky]; !ok {
+		commandDirectory[ky] = &Command{
+			ID:      id,
+			Method:  method,
+			Tags:    tags,
+			Handler: []*ServiceInstance{handler},
+		}
+	} else {
+		commandDirectory[ky].Handler = append(commandDirectory[ky].Handler, handler)
+		commandDirectory[ky].Tags = lo.Uniq(append(commandDirectory[ky].Tags, tags...))
+	}
+
+	commandDirectory[ky].Handler = lo.UniqBy(commandDirectory[ky].Handler, func(item *ServiceInstance) string {
+		return item.ID
+	})
+
+	log.Info().Str("id", id).Str("method", method).Str("tags", strings.Join(tags, ",")).Msg("New command registered")
+}
+
+func GetCommandHandler(id, method string) *ServiceInstance {
+	commandDirectoryMutex.Lock()
+	defer commandDirectoryMutex.Unlock()
+
+	ky := nex.GetCommandKey(id, method)
+	if val, ok := commandDirectory[ky]; ok {
+		if len(val.Handler) == 0 {
+			return nil
+		}
+
+		idx := val.robinIndex % uint(len(val.Handler))
+		val.robinIndex = idx + 1
+		return val.Handler[idx]
+	}
+
+	return nil
+}
+
+func RemoveCommand(id, method string) {
+	commandDirectoryMutex.Lock()
+	defer commandDirectoryMutex.Unlock()
+
+	ky := nex.GetCommandKey(id, method)
+	delete(commandDirectory, ky)
+}

pkg/internal/directory/command_rpc.go

@@ -0,0 +1,116 @@
+package directory
+
+import (
+	"context"
+	"git.solsynth.dev/hypernet/nexus/pkg/proto"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"io"
+	"net/http"
+	"time"
+)
+
+type CommandRpcServer struct {
+	proto.UnimplementedCommandControllerServer
+}
+
+func (c CommandRpcServer) AddCommand(ctx context.Context, info *proto.CommandInfo) (*proto.AddCommandResponse, error) {
+	clientId, err := GetClientId(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	service := GetServiceInstance(clientId)
+	if service == nil {
+		return nil, status.Errorf(codes.NotFound, "service not found")
+	}
+
+	AddCommand(info.GetId(), info.GetMethod(), info.GetTags(), service)
+	return &proto.AddCommandResponse{
+		IsSuccess: true,
+	}, nil
+}
+
+func (c CommandRpcServer) RemoveCommand(ctx context.Context, request *proto.CommandLookupRequest) (*proto.RemoveCommandResponse, error) {
+	RemoveCommand(request.GetId(), request.GetMethod())
+	return &proto.RemoveCommandResponse{
+		IsSuccess: true,
+	}, nil
+}
+
+func (c CommandRpcServer) SendCommand(ctx context.Context, argument *proto.CommandArgument) (*proto.CommandReturn, error) {
+	id := argument.GetCommand()
+	method := argument.GetMethod()
+
+	handler := GetCommandHandler(id, method)
+	if handler == nil {
+		return &proto.CommandReturn{
+			IsDelivered: false,
+			Status:      http.StatusNotFound,
+			ContentType: "text/plain+error",
+			Payload:     []byte("command not found"),
+		}, nil
+	}
+
+	conn, err := handler.GetGrpcConn()
+	if err != nil {
+		return &proto.CommandReturn{
+			IsDelivered: false,
+			Status:      http.StatusServiceUnavailable,
+			ContentType: "text/plain+error",
+			Payload:     []byte("service unavailable"),
+		}, nil
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
+	defer cancel()
+
+	out, err := proto.NewCommandControllerClient(conn).SendCommand(ctx, argument)
+	if err != nil {
+		return &proto.CommandReturn{
+			IsDelivered: true,
+			Status:      http.StatusInternalServerError,
+			ContentType: "text/plain+error",
+			Payload:     []byte(err.Error()),
+		}, nil
+	}
+	out.IsDelivered = true
+	return out, nil
+}
+
+func (c CommandRpcServer) SendStreamCommand(g grpc.BidiStreamingServer[proto.CommandArgument, proto.CommandReturn]) error {
+	for {
+		pck, err := g.Recv()
+		if err == io.EOF {
+			return nil
+		} else if err != nil {
+			return err
+		}
+
+		id := pck.GetCommand()
+		method := pck.GetMethod()
+
+		handler := GetCommandHandler(id, method)
+		if handler == nil {
+			return status.Errorf(codes.NotFound, "command not found")
+		}
+
+		conn, err := handler.GetGrpcConn()
+
+		ctx, cancel := context.WithTimeout(g.Context(), time.Second*10)
+		out, err := proto.NewCommandControllerClient(conn).SendCommand(ctx, pck)
+		cancel()
+
+		if err != nil {
+			_ = g.Send(&proto.CommandReturn{
+				IsDelivered: false,
+				Status:      http.StatusInternalServerError,
+				ContentType: "text/plain+error",
+				Payload:     []byte(err.Error()),
+			})
+		} else {
+			_ = g.Send(out)
+		}
+	}
+}

pkg/internal/directory/connect.go

@@ -0,0 +1,29 @@
+package directory
+
+import (
+	"context"
+	"fmt"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	health "google.golang.org/grpc/health/grpc_health_v1"
+	"time"
+)
+
+func ConnectService(in *ServiceInstance) (*grpc.ClientConn, error) {
+	conn, err := grpc.NewClient(
+		in.GrpcAddr,
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create grpc connection: %v", err)
+	}
+
+	client := health.NewHealthClient(conn)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+	defer cancel()
+	if _, err = client.Check(ctx, &health.HealthCheckRequest{}); err != nil {
+		return conn, fmt.Errorf("grpc service is down: %v", err)
+	}
+
+	return conn, nil
+}

pkg/internal/directory/exts.go

@@ -0,0 +1,20 @@
+package directory
+
+import (
+	"context"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+func GetClientId(ctx context.Context) (string, error) {
+	var clientId string
+	if md, ok := metadata.FromIncomingContext(ctx); !ok {
+		return clientId, status.Errorf(codes.InvalidArgument, "missing metadata")
+	} else if val, ok := md["client_id"]; !ok || len(val) == 0 {
+		return clientId, status.Errorf(codes.Unauthenticated, "missing client_id in metadata")
+	} else {
+		clientId = val[0]
+	}
+	return clientId, nil
+}

pkg/internal/directory/service.go

@@ -0,0 +1,29 @@
+package directory
+
+import "google.golang.org/grpc"
+
+type ServiceInstance struct {
+	ID       string  `json:"id"`
+	Type     string  `json:"type"`
+	Label    string  `json:"label"`
+	GrpcAddr string  `json:"grpc_addr"`
+	HttpAddr *string `json:"http_addr"`
+
+	grpcConn   *grpc.ClientConn
+	retryCount int
+}
+
+func (v *ServiceInstance) GetGrpcConn() (*grpc.ClientConn, error) {
+	if v.grpcConn != nil {
+		return v.grpcConn, nil
+	}
+
+	var err error
+	v.grpcConn, err = ConnectService(v)
+	if err != nil {
+		RemoveServiceInstance(v.ID)
+		return nil, err
+	}
+
+	return v.grpcConn, nil
+}

pkg/internal/directory/service_mapping.go

@@ -0,0 +1,78 @@
+package directory
+
+import (
+	"context"
+	"git.solsynth.dev/hypernet/nexus/pkg/nex"
+	"git.solsynth.dev/hypernet/nexus/pkg/proto"
+	"sync"
+	"time"
+)
+
+// In services, we use sync.Map because it will be both often read and write
+var serviceDirectory sync.Map
+
+func GetServiceInstance(id string) *ServiceInstance {
+	val, ok := serviceDirectory.Load(id)
+	if ok {
+		return val.(*ServiceInstance)
+	} else {
+		return nil
+	}
+}
+
+func GetServiceInstanceByType(t string) *ServiceInstance {
+	var result *ServiceInstance
+	serviceDirectory.Range(func(key, value any) bool {
+		if value.(*ServiceInstance).Type == t {
+			result = value.(*ServiceInstance)
+			return false
+		}
+		return true
+	})
+	return result
+}
+
+func ListServiceInstance() []*ServiceInstance {
+	var result []*ServiceInstance
+	serviceDirectory.Range(func(key, value interface{}) bool {
+		result = append(result, value.(*ServiceInstance))
+		return true
+	})
+	return result
+}
+
+func ListServiceInstanceByType(t string) []*ServiceInstance {
+	var result []*ServiceInstance
+	serviceDirectory.Range(func(key, value interface{}) bool {
+		if value.(*ServiceInstance).Type == t {
+			result = append(result, value.(*ServiceInstance))
+		}
+		return true
+	})
+	return result
+}
+
+func AddServiceInstance(in *ServiceInstance) {
+	serviceDirectory.Store(in.ID, in)
+}
+
+func RemoveServiceInstance(id string) {
+	serviceDirectory.Delete(id)
+}
+
+func BroadcastEvent(event string, data any) {
+	serviceDirectory.Range(func(key, value any) bool {
+		conn, err := value.(*ServiceInstance).GetGrpcConn()
+		if err != nil {
+			return true
+		}
+
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+		_, _ = proto.NewServiceDirectoryClient(conn).BroadcastEvent(ctx, &proto.EventInfo{
+			Event: event,
+			Data:  nex.EncodeMap(data),
+		})
+		return true
+	})
+}

pkg/internal/directory/service_rpc.go

@@ -0,0 +1,91 @@
+package directory
+
+import (
+	"context"
+	"fmt"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"git.solsynth.dev/hypernet/nexus/pkg/proto"
+	"github.com/rs/zerolog/log"
+	"github.com/samber/lo"
+)
+
+type ServiceRpcServer struct {
+	proto.UnimplementedServiceDirectoryServer
+}
+
+func instantiationService(in *ServiceInstance) *proto.ServiceInfo {
+	if in == nil {
+		return nil
+	}
+	return &proto.ServiceInfo{
+		Id:       in.ID,
+		Type:     in.Type,
+		Label:    in.Label,
+		GrpcAddr: in.GrpcAddr,
+		HttpAddr: in.HttpAddr,
+	}
+}
+
+func (v *ServiceRpcServer) GetService(ctx context.Context, request *proto.GetServiceRequest) (*proto.GetServiceResponse, error) {
+	if request.Id != nil {
+		out := GetServiceInstance(request.GetId())
+		return &proto.GetServiceResponse{
+			Data: instantiationService(out),
+		}, nil
+	}
+	if request.Type != nil {
+		out := GetServiceInstanceByType(request.GetType())
+		return &proto.GetServiceResponse{
+			Data: instantiationService(out),
+		}, nil
+	}
+	return nil, fmt.Errorf("no filter condition is provided")
+}
+
+func (v *ServiceRpcServer) ListService(ctx context.Context, request *proto.ListServiceRequest) (*proto.ListServiceResponse, error) {
+	var out []*ServiceInstance
+	if request.Type != nil {
+		out = ListServiceInstanceByType(request.GetType())
+	} else {
+		out = ListServiceInstance()
+	}
+	return &proto.ListServiceResponse{
+		Data: lo.Map(out, func(item *ServiceInstance, index int) *proto.ServiceInfo {
+			return instantiationService(item)
+		}),
+	}, nil
+}
+
+func (v *ServiceRpcServer) AddService(ctx context.Context, info *proto.ServiceInfo) (*proto.AddServiceResponse, error) {
+	clientId, err := GetClientId(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	if info.GetId() != clientId {
+		return nil, status.Errorf(codes.InvalidArgument, "client_id mismatch in metadata")
+	}
+
+	in := &ServiceInstance{
+		ID:       clientId,
+		Type:     info.GetType(),
+		Label:    info.GetLabel(),
+		GrpcAddr: info.GetGrpcAddr(),
+		HttpAddr: info.HttpAddr,
+	}
+	AddServiceInstance(in)
+	log.Info().Str("id", clientId).Str("label", info.GetLabel()).Msg("New service registered")
+	return &proto.AddServiceResponse{
+		IsSuccess: true,
+	}, nil
+}
+
+func (v *ServiceRpcServer) RemoveService(ctx context.Context, request *proto.RemoveServiceRequest) (*proto.RemoveServiceResponse, error) {
+	RemoveServiceInstance(request.GetId())
+	log.Info().Str("id", request.GetId()).Msg("A service removed.")
+	return &proto.RemoveServiceResponse{
+		IsSuccess: true,
+	}, nil
+}