Replace TFWConnector with PipeIO in the webservice

solvable/Dockerfile

@@ -1,11 +1,5 @@
 FROM eu.gcr.io/avatao-challengestore/tutorial-framework
 
-# Install webservice dependencies
-RUN pip3 install Flask==1.0        \
-                 SQLAlchemy==1.2.7 \
-                 passlib==1.7.1    \
-                 git+https://github.com/avatao-content/tfwconnector.git#subdirectory=python3
-
 # Define variables to use later
 ENV TFW_EHMAIN_DIR="${TFW_DIR}/builtin_event_handlers" \
     TFW_WEBSERVICE_DIR="/srv/webservice"               \

solvable/src/webservice/pipe_io.py

@@ -0,0 +1,69 @@
+from typing import Callable
+
+
+class PipeReader:
+    def __init__(self, pipe_path):
+        self._pipe = open(pipe_path, 'rb')
+        self._message_handler = lambda msg: None
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type_, value, traceback):
+        self.close()
+
+    def close(self):
+        self._pipe.close()
+
+    @property
+    def message_handler(self):
+        return self._message_handler
+
+    @message_handler.setter
+    def message_handler(self, value):
+        if not isinstance(value, Callable):
+            raise ValueError("message_handler must be callable!")
+        self._message_handler = value
+
+    def run(self):
+        msg = self.recv_message()
+        while msg:
+            self._message_handler(msg)
+            msg = self.recv_message()
+
+    def recv_message(self):
+        return self._pipe.readline()[:-1]
+
+
+class PipeWriter:
+    def __init__(self, pipe_path):
+        self._pipe = open(pipe_path, 'wb')
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type_, value, traceback):
+        self.close()
+
+    def close(self):
+        self._pipe.close()
+
+    def send_message(self, message):
+        self._pipe.write(message + b'\n')
+        self._pipe.flush()
+
+
+class PipeIO:
+    def __init__(self, in_pipe_path, out_pipe_path):
+        self.reader = PipeReader(in_pipe_path)
+        self.writer = PipeWriter(out_pipe_path)
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type_, value, traceback):
+        self.close()
+
+    def close(self):
+        self.reader.close()
+        self.writer.close()

solvable/src/webservice/user_ops.py

@@ -1,7 +1,6 @@
-from functools import partial
+from json import dumps
-
-from tfwconnector import MessageSender
 
+from pipe_io import PipeWriter
 from crypto import PasswordHasher
 from model import User
 from errors import InvalidCredentialsError, UserExistsError
@@ -12,11 +11,14 @@ class UserOps:
         self.username = username
         self.password = password
         self.db_session = db_session
-        self.message_sender = MessageSender()
+        self.pipe = PipeWriter('/tmp/tfw_json_send')
-        self.log = partial(
+        self.log = lambda message: self.pipe.send_message(dumps({
-            self.message_sender.send,
+            'key': 'message',
-            'Authenticator'
+            'data': {
-        )
+                'originator': 'Authenticator',
+                'message': message
+            }
+        }).encode())
 
     def authenticate(self):
         """