From 02b84bd0188df372a1346a95e6c84b6cc2b4b2c1 Mon Sep 17 00:00:00 2001
From: Matthias <xmatthias@outlook.com>
Date: Thu, 31 Dec 2020 20:02:27 +0100
Subject: [PATCH] Introduce webserver mode for fastapi

---
 freqtrade/commands/trade_commands.py  | 10 +++++---
 freqtrade/enums/runmode.py            |  1 +
 freqtrade/rpc/api_server/webserver.py | 35 ++++++++++++++++++++++++---
 freqtrade/rpc/rpc_manager.py          |  7 +++---
 4 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/freqtrade/commands/trade_commands.py b/freqtrade/commands/trade_commands.py
index 69ea5998f..ca1451778 100644
--- a/freqtrade/commands/trade_commands.py
+++ b/freqtrade/commands/trade_commands.py
@@ -1,7 +1,6 @@
 import logging
 from typing import Any, Dict
 
-
 logger = logging.getLogger(__name__)
 
 
@@ -29,9 +28,14 @@ def start_trading(args: Dict[str, Any]) -> int:
     return 0
 
 
-def start_webserver(args: Dict[str, Any]) -> int:
+def start_webserver(args: Dict[str, Any]) -> None:
     """
     Main entry point for webserver mode
     """
+    from freqtrade.rpc.api_server import ApiServer
+    from freqtrade.configuration import Configuration
+    from freqtrade.enums import RunMode
 
-    print(args)
+    # Initialize configuration
+    config = Configuration(args, RunMode.WEBSERVER).get_config()
+    ApiServer(config, standalone=True)
diff --git a/freqtrade/enums/runmode.py b/freqtrade/enums/runmode.py
index 7826d1d0c..6545aaec7 100644
--- a/freqtrade/enums/runmode.py
+++ b/freqtrade/enums/runmode.py
@@ -14,6 +14,7 @@ class RunMode(Enum):
     UTIL_EXCHANGE = "util_exchange"
     UTIL_NO_EXCHANGE = "util_no_exchange"
     PLOT = "plot"
+    WEBSERVER = "webserver"
     OTHER = "other"
 
 
diff --git a/freqtrade/rpc/api_server/webserver.py b/freqtrade/rpc/api_server/webserver.py
index a43d4abe6..9cbd5512a 100644
--- a/freqtrade/rpc/api_server/webserver.py
+++ b/freqtrade/rpc/api_server/webserver.py
@@ -8,6 +8,7 @@ from fastapi import Depends, FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from starlette.responses import JSONResponse
 
+from freqtrade.exceptions import OperationalException
 from freqtrade.rpc.api_server.uvicorn_threaded import UvicornServer
 from freqtrade.rpc.rpc import RPC, RPCException, RPCHandler
 
@@ -28,16 +29,30 @@ class FTJSONResponse(JSONResponse):
 
 class ApiServer(RPCHandler):
 
+    __instance = None
+    __initialized = False
+
     _rpc: RPC
     _has_rpc: bool = False
     _config: Dict[str, Any] = {}
 
-    def __init__(self, rpc: RPC, config: Dict[str, Any]) -> None:
-        super().__init__(rpc, config)
+    def __new__(cls, *args, **kwargs):
+        """
+        This class is a singleton.
+        We'll only have one instance of it around.
+        """
+        if ApiServer.__instance is None:
+            ApiServer.__instance = object.__new__(cls)
+            ApiServer.__initialized = False
+        return ApiServer.__instance
+
+    def __init__(self, config: Dict[str, Any], standalone: bool = False) -> None:
+        if self.__initialized and (standalone or self._standalone):
+            return
+        self._standalone: bool = standalone
+        self._config = config
         self._server = None
 
-        ApiServer._rpc = rpc
-        ApiServer._has_rpc = True
         ApiServer._config = config
         api_config = self._config['api_server']
 
@@ -50,6 +65,18 @@ class ApiServer(RPCHandler):
 
         self.start_api()
 
+    def add_rpc_handler(self, rpc: RPC):
+        """
+        Attach rpc handler
+        """
+        if not self._rpc:
+            self._rpc = rpc
+            ApiServer._rpc = rpc
+            ApiServer._has_rpc = True
+        else:
+            # This should not happen assuming we didn't mess up.
+            raise OperationalException('RPC Handler already attached.')
+
     def cleanup(self) -> None:
         """ Cleanup pending module resources """
         if self._server:
diff --git a/freqtrade/rpc/rpc_manager.py b/freqtrade/rpc/rpc_manager.py
index 18ed68041..8814f70a0 100644
--- a/freqtrade/rpc/rpc_manager.py
+++ b/freqtrade/rpc/rpc_manager.py
@@ -36,15 +36,16 @@ class RPCManager:
         if config.get('api_server', {}).get('enabled', False):
             logger.info('Enabling rpc.api_server')
             from freqtrade.rpc.api_server import ApiServer
-
-            self.registered_modules.append(ApiServer(self._rpc, config))
+            apiserver = ApiServer(config)
+            apiserver.add_rpc_handler(self._rpc)
+            self.registered_modules.append(apiserver)
 
     def cleanup(self) -> None:
         """ Stops all enabled rpc modules """
         logger.info('Cleaning up rpc modules ...')
         while self.registered_modules:
             mod = self.registered_modules.pop()
-            logger.debug('Cleaning up rpc.%s ...', mod.name)
+            logger.info('Cleaning up rpc.%s ...', mod.name)
             mod.cleanup()
             del mod