feat: CLI command 'feast serve' should start go-based server if flag is enabled

Makefile

@@ -167,7 +167,7 @@ compile-protos-go: install-go-proto-dependencies install-protoc-dependencies
 	cd sdk/python && python setup.py build_go_protos
 
 compile-go-lib: install-go-proto-dependencies install-go-ci-dependencies
-	cd sdk/python && python setup.py build_go_lib
+	cd sdk/python && COMPILE_GO=True python setup.py build_ext --inplace
 
 # Needs feast package to setup the feature store
 test-go: compile-protos-go
@@ -178,7 +178,7 @@ format-go:
 	gofmt -s -w go/
 
 lint-go: compile-protos-go
-	go vet ./go/internal/feast ./go/cmd/server
+	go vet ./go/internal/feast ./go/embedded
 
 # Docker
 

go/embedded/online_features.go

@@ -3,7 +3,15 @@ package embedded
 import (
 	"context"
 	"fmt"
+	"github.com/feast-dev/feast/go/internal/feast/server"
+	"github.com/feast-dev/feast/go/internal/feast/server/logging"
+	"github.com/feast-dev/feast/go/protos/feast/serving"
+	"google.golang.org/grpc"
 	"log"
+	"net"
+	"os"
+	"os/signal"
+	"syscall"
 
 	"github.com/apache/arrow/go/v8/arrow"
 	"github.com/apache/arrow/go/v8/arrow/array"
@@ -198,6 +206,36 @@ func (s *OnlineFeatureService) GetOnlineFeatures(
 	return nil
 }
 
+func (s *OnlineFeatureService) StartGprcServer(host string, port int) error {
+	// TODO(oleksii): enable logging
+	// Disable logging for now
+	var loggingService *logging.LoggingService = nil
+	ser := server.NewGrpcServingServiceServer(s.fs, loggingService)
+	log.Printf("Starting a gRPC server on host %s port %d\n", host, port)
+	lis, err := net.Listen("tcp", fmt.Sprintf("%s:%d", host, port))
+	if err != nil {
+		return err
+	}
+	grpcServer := grpc.NewServer()
+	serving.RegisterServingServiceServer(grpcServer, ser)
+
+	// Notify this channel when receiving interrupt or termination signals from OS
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		// As soon as these signals are received from OS, try to gracefully stop the gRPC server
+		<-c
+		fmt.Println("Stopping the gRPC server...")
+		grpcServer.GracefulStop()
+	}()
+
+	err = grpcServer.Serve(lis)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 /*
 	Read Record Batch from memory managed by Python caller.
 	Python part uses C ABI interface to export this record into C Data Interface,

go/internal/feast/onlinestore/onlinestore.go

@@ -43,7 +43,8 @@ type OnlineStore interface {
 
 func getOnlineStoreType(onlineStoreConfig map[string]interface{}) (string, bool) {
 	if onlineStoreType, ok := onlineStoreConfig["type"]; !ok {
-		return "", false
+		// If online store type isn't specified, default to sqlite
+		return "sqlite", true
 	} else {
 		result, ok := onlineStoreType.(string)
 		return result, ok
@@ -53,10 +54,11 @@ func getOnlineStoreType(onlineStoreConfig map[string]interface{}) (string, bool)
 func NewOnlineStore(config *registry.RepoConfig) (OnlineStore, error) {
 	onlineStoreType, ok := getOnlineStoreType(config.OnlineStore)
 	if !ok {
+		return nil, fmt.Errorf("could not get online store type from online store config: %+v", config.OnlineStore)
+	} else if onlineStoreType == "sqlite" {
 		onlineStore, err := NewSqliteOnlineStore(config.Project, config, config.OnlineStore)
 		return onlineStore, err
-	}
-	if onlineStoreType == "redis" {
+	} else if onlineStoreType == "redis" {
 		onlineStore, err := NewRedisOnlineStore(config.Project, config.OnlineStore)
 		return onlineStore, err
 	} else {

go/cmd/server/server.go → go/internal/feast/server/grpc_server.go

@@ -1,27 +1,29 @@
-package main
+package server
 
 import (
 	"context"
 
-	"github.com/feast-dev/feast/go/cmd/server/logging"
 	"github.com/feast-dev/feast/go/internal/feast"
+	"github.com/feast-dev/feast/go/internal/feast/server/logging"
 	"github.com/feast-dev/feast/go/protos/feast/serving"
 	prototypes "github.com/feast-dev/feast/go/protos/feast/types"
 	"github.com/feast-dev/feast/go/types"
 	"github.com/google/uuid"
 )
 
-type servingServiceServer struct {
+const feastServerVersion = "0.0.1"
+
+type grpcServingServiceServer struct {
 	fs             *feast.FeatureStore
 	loggingService *logging.LoggingService
 	serving.UnimplementedServingServiceServer
 }
 
-func newServingServiceServer(fs *feast.FeatureStore, loggingService *logging.LoggingService) *servingServiceServer {
-	return &servingServiceServer{fs: fs, loggingService: loggingService}
+func NewGrpcServingServiceServer(fs *feast.FeatureStore, loggingService *logging.LoggingService) *grpcServingServiceServer {
+	return &grpcServingServiceServer{fs: fs, loggingService: loggingService}
 }
 
-func (s *servingServiceServer) GetFeastServingInfo(ctx context.Context, request *serving.GetFeastServingInfoRequest) (*serving.GetFeastServingInfoResponse, error) {
+func (s *grpcServingServiceServer) GetFeastServingInfo(ctx context.Context, request *serving.GetFeastServingInfoRequest) (*serving.GetFeastServingInfoResponse, error) {
 	return &serving.GetFeastServingInfoResponse{
 		Version: feastServerVersion,
 	}, nil
@@ -30,7 +32,7 @@ func (s *servingServiceServer) GetFeastServingInfo(ctx context.Context, request
 // Returns an object containing the response to GetOnlineFeatures.
 // Metadata contains featurenames that corresponds to the number of rows in response.Results.
 // Results contains values including the value of the feature, the event timestamp, and feature status in a columnar format.
-func (s *servingServiceServer) GetOnlineFeatures(ctx context.Context, request *serving.GetOnlineFeaturesRequest) (*serving.GetOnlineFeaturesResponse, error) {
+func (s *grpcServingServiceServer) GetOnlineFeatures(ctx context.Context, request *serving.GetOnlineFeaturesRequest) (*serving.GetOnlineFeaturesResponse, error) {
 	requestId := GenerateRequestId()
 	featuresOrService, err := s.fs.ParseFeatures(request.GetKind())
 	if err != nil {
@@ -74,7 +76,7 @@ func (s *servingServiceServer) GetOnlineFeatures(ctx context.Context, request *s
 			EventTimestamps: vector.Timestamps,
 		})
 	}
-	if featuresOrService.FeatureService != nil {
+	if featuresOrService.FeatureService != nil && s.loggingService != nil {
 		go s.loggingService.GenerateLogs(featuresOrService.FeatureService, entityValuesMap, resp.Results[len(request.Entities):], request.RequestContext, requestId)
 	}
 	return resp, nil

go/cmd/server/server_test.go → go/internal/feast/server/grpc_server_test.go

@@ -1,4 +1,4 @@
-package main
+package server
 
 import (
 	"context"
@@ -16,8 +16,8 @@ import (
 	"github.com/apache/arrow/go/v8/arrow/memory"
 	"github.com/apache/arrow/go/v8/parquet/file"
 	"github.com/apache/arrow/go/v8/parquet/pqarrow"
-	"github.com/feast-dev/feast/go/cmd/server/logging"
 	"github.com/feast-dev/feast/go/internal/feast"
+	"github.com/feast-dev/feast/go/internal/feast/server/logging"
 	"github.com/feast-dev/feast/go/internal/test"
 	"github.com/feast-dev/feast/go/protos/feast/serving"
 	"github.com/feast-dev/feast/go/protos/feast/types"
@@ -73,7 +73,7 @@ func getClient(ctx context.Context, offlineStoreType string, basePath string, en
 	if err != nil {
 		panic(err)
 	}
-	servingServiceServer := newServingServiceServer(fs, loggingService)
+	servingServiceServer := NewGrpcServingServiceServer(fs, loggingService)
 
 	serving.RegisterServingServiceServer(server, servingServiceServer)
 	go func() {

sdk/python/feast/embedded_go/online_features_service.py

@@ -132,6 +132,9 @@ def get_online_features(
         resp = record_batch_to_online_response(record_batch)
         return OnlineResponse(resp)
 
+    def start_grpc_server(self, host: str, port: int):
+        self._service.StartGprcServer(host, port)
+
 
 def _to_arrow(value, type_hint: Optional[ValueType]) -> pa.Array:
     if isinstance(value, Value_pb2.RepeatedValue):

sdk/python/feast/feature_store.py

@@ -111,7 +111,7 @@ class FeatureStore:
     repo_path: Path
     _registry: Registry
     _provider: Provider
-    _go_server: Optional["EmbeddedOnlineFeatureServer"]
+    _go_server: "EmbeddedOnlineFeatureServer"
 
     @log_exceptions
     def __init__(
@@ -1306,6 +1306,18 @@ def get_online_features(
             native_entity_values=True,
         )
 
+    def _lazy_init_go_server(self):
+        """Lazily initialize self._go_server if it hasn't been initialized before."""
+        from feast.embedded_go.online_features_service import (
+            EmbeddedOnlineFeatureServer,
+        )
+
+        # Lazily start the go server on the first request
+        if self._go_server is None:
+            self._go_server = EmbeddedOnlineFeatureServer(
+                str(self.repo_path.absolute()), self.config, self
+            )
+
     def _get_online_features(
         self,
         features: Union[List[str], FeatureService],
@@ -1323,15 +1335,7 @@ def _get_online_features(
 
         # If Go feature server is enabled, send request to it instead of going through regular Python logic
         if self.config.go_feature_retrieval:
-            from feast.embedded_go.online_features_service import (
-                EmbeddedOnlineFeatureServer,
-            )
-
-            # Lazily start the go server on the first request
-            if self._go_server is None:
-                self._go_server = EmbeddedOnlineFeatureServer(
-                    str(self.repo_path.absolute()), self.config, self
-                )
+            self._lazy_init_go_server()
 
             entity_native_values: Dict[str, List[Any]]
             if not native_entity_values:
@@ -1957,7 +1961,14 @@ def _get_feature_views_to_use(
     @log_exceptions_and_usage
     def serve(self, host: str, port: int, no_access_log: bool) -> None:
         """Start the feature consumption server locally on a given port."""
-        feature_server.start_server(self, host, port, no_access_log)
+        if self.config.go_feature_retrieval:
+            # Start go server instead of python if the flag is enabled
+            self._lazy_init_go_server()
+            # TODO(tsotne) add http/grpc flag in CLI and call appropriate method here depending on that
+            self._go_server.start_grpc_server(host, port)
+        else:
+            # Start the python server if go server isn't enabled
+            feature_server.start_server(self, host, port, no_access_log)
 
     @log_exceptions_and_usage
     def get_feature_server_endpoint(self) -> Optional[str]: