cli: add RPCServer commands

Author: utnapischtim

invenio_app/cli.py

@@ -2,15 +2,132 @@
 #
 # This file is part of Invenio.
 # Copyright (C) 2017-2018 CERN.
+# Copyright (C) 2025 Graz University of Technology.
 #
 # Invenio is free software; you can redistribute it and/or modify it
 # under the terms of the MIT License; see LICENSE file for more details.
 
 """CLI application for Invenio flavours."""
 
+import contextlib
+import io
+import pickle
+import socket
+import socketserver
+
+from click import group, option, pass_context, secho
+from flask.cli import with_appcontext
 from invenio_base.app import create_cli
 
 from .factory import create_app
 
 #: Invenio CLI application.
 cli = create_cli(create_app=create_app)
+
+
+class RPCRequestHandler(socketserver.BaseRequestHandler):
+    """RPCRequestHandler."""
+
+    def handle(self):
+        """Handles the requests to the RPCServer."""
+        data = self.request.recv(4096)
+        if not data:
+            return
+
+        try:
+            command_parts = pickle.loads(data)
+
+            if not isinstance(command_parts, list) or len(command_parts) == 0:
+                raise ValueError("Invalid command format should be a list.")
+
+            if command_parts[0] == "ping":
+                result = "pong"
+            else:
+                output_buffer = io.StringIO()
+                with contextlib.redirect_stdout(output_buffer):
+                    cli.main(args=command_parts, standalone_mode=False)
+                result = output_buffer.getvalue().strip()
+
+            response = pickle.dumps({"success": True, "result": result})
+        except Exception as e:
+            response = pickle.dumps({"success": False, "error": str(e)})
+
+        self.request.sendall(response)
+
+
+class RPCServer(socketserver.TCPServer):
+    """RPCServer implementation."""
+
+    allow_reuse_address = True
+
+    def shutdown_server(self):
+        """Shutdown the server."""
+        secho("Shutting down RPC Server...", fg="green")
+        self.shutdown()
+        self.server_close()
+
+
+def send(host, port, args):
+    """Send."""
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        s.connect((host, port))
+        s.sendall(pickle.dumps(list(args)))
+
+        return pickle.loads(s.recv(4096))
+
+
+@group()
+def rpc_server():
+    """RPC server."""
+
+
+@rpc_server.command("start")
+@option("--port", default=5000)
+@option("--host", default="localhost")
+@with_appcontext
+def rpc_server_start(port, host):
+    """Start rpc server."""
+    server = RPCServer((host, port), RPCRequestHandler)
+
+    secho(
+        f"RPC Server is running on port {host}:{port}... (Press Ctrl+C to stop)",
+        fg="green",
+    )
+
+    try:
+        server.serve_forever()
+    except KeyboardInterrupt:
+        server.shutdown()
+
+
+@rpc_server.command(
+    "send",
+    context_settings={"allow_extra_args": True, "ignore_unknown_options": True},
+)
+@option("--port", default=5000)
+@option("--host", default="localhost")
+@option("--plain", is_flag=True, default=False)
+@pass_context
+def rpc_server_send(ctx, port, host, plain):
+    """Send."""
+    response = send(host, port, ctx.args)
+
+    if response["success"]:
+        prefix = "" if plain else "Response: "
+        color = "green"
+        message = response["result"]
+    else:
+        prefix = "" if plain else "Error: "
+        color = "red"
+        message = response["error"]
+
+    secho(f"{prefix}{message}", fg=color)
+
+
+@rpc_server.command("ping")
+@option("--port", default=5000)
+@option("--host", default="localhost")
+def rpc_server_ping(port, host):
+    """Ping."""
+    response = send(host, port, ["ping"])
+    secho(response["result"])

setup.cfg

@@ -3,7 +3,7 @@
 # This file is part of Invenio.
 # Copyright (C) 2017-2022 CERN.
 # Copyright (C) 2021      TU Wien.
-# Copyright (C) 2022-2024 Graz University of Technology.
+# Copyright (C) 2022-2025 Graz University of Technology.
 #
 # Invenio is free software; you can redistribute it and/or modify it
 # under the terms of the MIT License; see LICENSE file for more details.
@@ -48,6 +48,9 @@ tests =
 [options.entry_points]
 console_scripts =
     invenio = invenio_app.cli:cli
+    rpc-server = invenio_app.cli:rpc_server
+flask.commands =
+    rpc-server = invenio_app.cli:rpc_server
 invenio_base.api_apps =
     invenio_app = invenio_app:InvenioApp
 invenio_base.apps =