feat: Implement gRPC server to ingest streaming features

protos/feast/serving/GrpcServer.proto

@@ -0,0 +1,27 @@
+syntax = "proto3";
+
+message PushRequest {
+    map<string, string> features = 1;
+    string stream_feature_view = 2;
+    bool allow_registry_cache = 3;
+    string to = 4;
+}
+
+message PushResponse {
+  bool status = 1;
+}
+
+message WriteToOnlineStoreRequest {
+    map<string, string> features = 1;
+    string feature_view_name = 2;
+    bool allow_registry_cache = 3;
+}
+
+message WriteToOnlineStoreResponse {
+  bool status = 1;
+}
+
+service GrpcFeatureServer {
+  rpc Push (PushRequest) returns (PushResponse) {};
+  rpc WriteToOnlineStore (WriteToOnlineStoreRequest) returns (WriteToOnlineStoreResponse);
+}

sdk/python/feast/cli.py

@@ -26,8 +26,10 @@
 
 from feast import utils
 from feast.constants import DEFAULT_FEATURE_TRANSFORMATION_SERVER_PORT
+from feast.data_source import PushMode
 from feast.errors import FeastObjectNotFoundException, FeastProviderLoginError
 from feast.feature_view import FeatureView
+from feast.infra.contrib.grpc_server import get_grpc_server
 from feast.on_demand_feature_view import OnDemandFeatureView
 from feast.repo_config import load_repo_config
 from feast.repo_operations import (
@@ -689,6 +691,36 @@ def serve_command(
     )
 
 
+@cli.command("listen")
+@click.option(
+    "--address",
+    "-a",
+    type=click.STRING,
+    default="localhost:50051",
+    show_default=True,
+    help="Address of the gRPC server",
+)
+@click.option(
+    "--max_workers",
+    "-w",
+    type=click.INT,
+    default=10,
+    show_default=False,
+    help="The maximum number of threads that can be used to execute the gRPC calls",
+)
+@click.pass_context
+def listen_command(
+    ctx: click.Context,
+    address: str,
+    max_workers: int,
+):
+    """Start a gRPC feature server to ingest streaming features on given address"""
+    store = create_feature_store(ctx)
+    server = get_grpc_server(address, store, max_workers)
+    server.start()
+    server.wait_for_termination()
+
+
 @cli.command("serve_transformations")
 @click.option(
     "--port",

sdk/python/feast/infra/contrib/grpc_server.py

@@ -0,0 +1,95 @@
+import logging
+from concurrent import futures
+
+import grpc
+import pandas as pd
+from grpc_health.v1 import health, health_pb2_grpc
+
+from feast.data_source import PushMode
+from feast.errors import PushSourceNotFoundException
+from feast.feature_store import FeatureStore
+from feast.protos.feast.serving.GrpcServer_pb2 import (
+    PushResponse,
+    WriteToOnlineStoreResponse,
+)
+from feast.protos.feast.serving.GrpcServer_pb2_grpc import (
+    GrpcFeatureServerServicer,
+    add_GrpcFeatureServerServicer_to_server,
+)
+
+
+def parse(features):
+    df = {}
+    for i in features.keys():
+        df[i] = [features.get(i)]
+    return pd.DataFrame.from_dict(df)
+
+
+class GrpcFeatureServer(GrpcFeatureServerServicer):
+    fs: FeatureStore
+
+    def __init__(self, fs: FeatureStore):
+        self.fs = fs
+        super().__init__()
+
+    def Push(self, request, context):
+        try:
+            df = parse(request.features)
+            if request.to == "offline":
+                to = PushMode.OFFLINE
+            elif request.to == "online":
+                to = PushMode.ONLINE
+            elif request.to == "online_and_offline":
+                to = PushMode.ONLINE_AND_OFFLINE
+            else:
+                raise ValueError(
+                    f"{request.to} is not a supported push format. Please specify one of these ['online', 'offline', "
+                    f"'online_and_offline']."
+                )
+            self.fs.push(
+                push_source_name=request.push_source_name,
+                df=df,
+                allow_registry_cache=request.allow_registry_cache,
+                to=to,
+            )
+        except PushSourceNotFoundException as e:
+            logging.exception(str(e))
+            context.set_code(grpc.StatusCode.INVALID_ARGUMENT)
+            context.set_details(str(e))
+            return PushResponse(status=False)
+        except Exception as e:
+            logging.exception(str(e))
+            context.set_code(grpc.StatusCode.INTERNAL)
+            context.set_details(str(e))
+            return PushResponse(status=False)
+        return PushResponse(status=True)
+
+    def WriteToOnlineStore(self, request, context):
+        logging.warning(
+            "write_to_online_store is deprecated. Please consider using Push instead"
+        )
+        try:
+            df = parse(request.features)
+            self.fs.write_to_online_store(
+                feature_view_name=request.feature_view_name,
+                df=df,
+                allow_registry_cache=request.allow_registry_cache,
+            )
+        except Exception as e:
+            logging.exception(str(e))
+            context.set_code(grpc.StatusCode.INTERNAL)
+            context.set_details(str(e))
+            return PushResponse(status=False)
+        return WriteToOnlineStoreResponse(status=True)
+
+
+def get_grpc_server(address: str, fs: FeatureStore, max_workers: int):
+    server = grpc.server(futures.ThreadPoolExecutor(max_workers=max_workers))
+    add_GrpcFeatureServerServicer_to_server(GrpcFeatureServer(fs), server)
+    health_servicer = health.HealthServicer(
+        experimental_non_blocking=True,
+        experimental_thread_pool=futures.ThreadPoolExecutor(max_workers=max_workers),
+    )
+    health_pb2_grpc.add_HealthServicer_to_server(health_servicer, server)
+    server.add_insecure_port(address)
+    return server