[ATO-1652] Add gRPC support

Makefile

@@ -20,7 +20,6 @@ install:
 	poetry run python -m pip install -U pip
 	poetry install
 
-
 clean:
 	find . -name '*.pyc' -exec rm -f {} +
 	find . -name '*.pyo' -exec rm -f {} +
@@ -37,7 +36,7 @@ formatter:
 
 lint:
 	poetry run ruff check rasa_sdk tests --ignore D
-	poetry run black --check rasa_sdk tests
+	poetry run black --exclude="rasa_sdk/grpc_py" --check rasa_sdk tests
 	make lint-docstrings
 
  # Compare against `main` if no branch was provided
@@ -62,3 +61,11 @@ cleanup-generated-changelog:
 release:
 	poetry run python scripts/release.py
 
+generate-grpc:
+	 python -m grpc_tools.protoc \
+	 	-Irasa_sdk/grpc_py=./proto \
+	 	--python_out=. \
+	 	--grpc_python_out=. \
+	 	--pyi_out=. \
+	 	proto/action_webhook.proto \
+	 	proto/health.proto

changelog/1109.feature.md

@@ -0,0 +1,6 @@
+Rasa SDK now supports gRPC protocol. 
+This allows users to use gRPC to invoke custom actions.
+Users can use secure (TLS) and insecure connections to communicate over gRPC.
+To start action server with gRPC use `--grpc` flag.
+For SSL support, users can provide `--ssl-keyfile`,  `--ssl-certificate` and `--ssl-ca-file`.
+Support for `--ssl-password` is not available yet due to a limitation in the gRPC Python library.

proto/action_webhook.proto

@@ -0,0 +1,68 @@
+syntax = "proto3";
+
+package action_server_webhook;
+import "google/protobuf/struct.proto";
+
+service ActionService {
+    rpc Webhook (WebhookRequest) returns (WebhookResponse);
+    rpc Actions (ActionsRequest) returns (ActionsResponse);
+}
+
+message ActionsRequest {}
+
+message ActionsResponse {
+    map<string, string> actions = 1;
+}
+
+message Tracker {
+    string sender_id = 1;
+    google.protobuf.Struct slots = 2;
+    google.protobuf.Struct latest_message = 3;
+    repeated google.protobuf.Struct events = 4;
+    bool paused = 5;
+    optional string followup_action = 6;
+    map<string, string> active_loop = 7;
+    optional string latest_action_name = 8;
+    repeated google.protobuf.Struct stack = 9;
+}
+
+message Intent {
+    string string_value = 1;
+    google.protobuf.Struct dict_value = 2;
+}
+
+message Entity {
+    string string_value = 1;
+    google.protobuf.Struct dict_value = 2;
+}
+
+message Action {
+    string string_value = 1;
+    google.protobuf.Struct dict_value = 2;
+}
+
+message Domain {
+    google.protobuf.Struct config = 1;
+    google.protobuf.Struct session_config = 2;
+    repeated Intent intents = 3;
+    repeated Entity entities = 4;
+    google.protobuf.Struct slots = 5;
+    google.protobuf.Struct responses = 6;
+    repeated Action actions = 7;
+    google.protobuf.Struct forms = 8;
+    repeated google.protobuf.Struct e2e_actions = 9;
+}
+
+message WebhookRequest {
+    string next_action = 1;
+    string sender_id = 2;
+    Tracker tracker = 3;
+    Domain domain = 4;
+    string version = 5;
+    optional string domain_digest = 6;
+}
+
+message WebhookResponse {
+    repeated google.protobuf.Struct events = 1;
+    repeated google.protobuf.Struct responses = 2;
+}

proto/health.proto

@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package grpc.health.v1;
+
+message HealthCheckRequest {}
+
+message HealthCheckResponse {}
+
+service HealthService {
+  rpc Check(HealthCheckRequest) returns (HealthCheckResponse);
+}

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "poetry.core.masonry.api"
 [tool.black]
 line-length = 88
 target-version = [ "py37", "py38", "py39", "py310",]
-exclude = "((.eggs | .git | .mypy_cache | .pytest_cache | build | dist))"
+exclude = "((.eggs | .git | .mypy_cache | .pytest_cache | build | dist ))"
 
 [tool.poetry]
 name = "rasa-sdk"
@@ -67,11 +67,13 @@ ignore_missing_imports = true
 show_error_codes = true
 warn_redundant_casts = true
 warn_unused_ignores = true
+exclude = "rasa_sdk/grpc_py"
 
 [tool.ruff]
 ignore = [ "D100", "D104", "D105", "RUF005",]
 line-length = 88
 select = [ "D", "E", "F", "W", "RUF",]
+exclude = [ "rasa_sdk/grpc_py" ]
 
 [tool.poetry.dependencies]
 python = ">=3.8,<3.11"
@@ -87,6 +89,10 @@ opentelemetry-api = "~1.15.0"
 opentelemetry-sdk = "~1.15.0"
 opentelemetry-exporter-jaeger = "~1.15.0"
 opentelemetry-exporter-otlp = "~1.15.0"
+grpcio = "1.59.3"
+protobuf = "4.25.3"
+grpcio-tools = "1.56.2"
+pydantic = "2.6.4"
 
 [tool.poetry.dev-dependencies]
 pytest-cov = "^4.1.0"
@@ -111,3 +117,4 @@ asyncio_mode = "auto"
 [tool.poetry.group.dev.dependencies]
 ruff = ">=0.0.256,<0.0.286"
 pytest-asyncio = "^0.21.0"
+types-protobuf = "4.25.0.20240417"

rasa_sdk/__main__.py

@@ -1,8 +1,12 @@
 import logging
+import asyncio
 
 from rasa_sdk import utils
 from rasa_sdk.endpoint import create_argument_parser, run
 from rasa_sdk.constants import APPLICATION_ROOT_LOGGER_NAME
+from rasa_sdk.grpc_server import run_grpc
+
+logger = logging.getLogger(__name__)
 
 
 def main_from_args(args):
@@ -18,20 +22,33 @@ def main_from_args(args):
     )
     utils.update_sanic_log_level()
 
-    run(
-        args.actions,
-        args.port,
-        args.cors,
-        args.ssl_certificate,
-        args.ssl_keyfile,
-        args.ssl_password,
-        args.auto_reload,
-        args.endpoints,
-    )
+    if args.grpc:
+        asyncio.run(
+            run_grpc(
+                args.actions,
+                args.port,
+                args.ssl_certificate,
+                args.ssl_keyfile,
+                args.ssl_ca_file,
+                args.auto_reload,
+                args.endpoints,
+            )
+        )
+    else:
+        run(
+            args.actions,
+            args.port,
+            args.cors,
+            args.ssl_certificate,
+            args.ssl_keyfile,
+            args.ssl_password,
+            args.auto_reload,
+            args.endpoints,
+        )
 
 
 def main():
-    # Running as standalone python application
+    """Runs the action server as standalone application."""
     arg_parser = create_argument_parser()
     cmdline_args = arg_parser.parse_args()
 

rasa_sdk/cli/arguments.py

@@ -3,17 +3,31 @@
 from rasa_sdk.constants import DEFAULT_SERVER_PORT, DEFAULT_ENDPOINTS_PATH
 
 
-def action_arg(action):
-    if "/" in action:
+def action_arg(actions_module_path: str) -> str:
+    """Validate the action module path.
+
+    Valid action module path is python module, so it should not contain a slash.
+
+    Args:
+        actions_module_path: Path to the actions python module.
+
+    Returns:
+        actions_module_path: If provided module path is valid.
+
+    Raises:
+        argparse.ArgumentTypeError: If the module path is invalid.
+    """
+    if "/" in actions_module_path:
         raise argparse.ArgumentTypeError(
             "Invalid actions format. Actions file should be a python module "
             "and passed with module notation (e.g. directory.actions)."
         )
     else:
-        return action
+        return actions_module_path
 
 
-def add_endpoint_arguments(parser):
+def add_endpoint_arguments(parser: argparse.ArgumentParser) -> None:
+    """Add all the arguments to the argument parser."""
     parser.add_argument(
         "-p",
         "--port",
@@ -47,7 +61,15 @@ def add_endpoint_arguments(parser):
         "--ssl-password",
         default=None,
         help="If your ssl-keyfile is protected by a password, you can specify it "
-        "using this paramer.",
+        "using this parameter. "
+        "Not supported in grpc mode.",
+    )
+    parser.add_argument(
+        "--ssl-ca-file",
+        default=None,
+        help="If you want to authenticate the client using a certificate, you can "
+        "specify the CA certificate of the client using this parameter. "
+        "Supported only in grpc mode.",
     )
     parser.add_argument(
         "--auto-reload",
@@ -59,3 +81,6 @@ def add_endpoint_arguments(parser):
         default=DEFAULT_ENDPOINTS_PATH,
         help="Configuration file for the assistant as a yml file.",
     )
+    parser.add_argument(
+        "--grpc", help="Starts grpc server instead of http", action="store_true"
+    )

rasa_sdk/constants.py

@@ -11,3 +11,4 @@
     "https://docs.python.org/3/library/logging.config.html#dictionary-schema-details"
 )
 DEFAULT_ENDPOINTS_PATH = "endpoints.yml"
+NO_GRACE_PERIOD = 0

rasa_sdk/endpoint.py

@@ -172,7 +172,10 @@ async def actions(_) -> HTTPResponse:
         if auto_reload:
             executor.reload()
 
-        body = [{"name": k} for k in executor.actions.keys()]
+        body = [
+            action_name_item.model_dump()
+            for action_name_item in executor.list_actions()
+        ]
         return response.json(body, status=200)
 
     @app.exception(Exception)