Replace gRPC with Flask

.github/workflows/backend.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: docker/build-push-action@v1
         with:
-          dockerfile: backend/Dockerfile
+          context: backend
           username: ${{ github.actor }}
           password: ${{ github.token }}
           registry: docker.pkg.github.com/polycortex/polydodo

.github/workflows/mobile.yml

@@ -21,12 +21,6 @@ jobs:
         with:
           java-version: "8.x"
       - uses: subosito/flutter-action@v1
-      - uses: abelfodil/protoc-action@v1
-        with:
-          enable-dart: true
-
-      - run: protoc --proto_path=protos protos/* --dart_out=grpc:mobile/lib/protos
-        working-directory: .
 
       - run: flutter pub get
 

.github/workflows/web.yml

@@ -14,10 +14,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
-      - uses: abelfodil/protoc-action@v1
-        with:
-          enable-grpc-web: true
-      - run: protoc protos/* --js_out=import_style=commonjs:web/src --grpc-web_out=import_style=commonjs,mode=grpcwebtext:web/src
+
       - run: yarn --cwd web install
       - run: yarn --cwd web build
       - uses: actions/upload-artifact@v2

README.md

@@ -4,29 +4,18 @@ This projects aims to offer a comprehensive guide to **record polysomnographic E
 
 ## Dev requirements
 
-### gRPC
-
-- Install `gRPC` package from your distribution's package manager
-- Install `protoc` compiler
-
 ### Web
 
 - Install Yarn package manager
-- `yarn global add protoc-gen-grpc-web`
-- Add `$HOME/.yarn/bin` to `PATH`
 
 ### Python
 
 - Install Python 3 and pip
 - Consider using `venv` to create a virtual environment
-- Install gRPC using a package manager or by compiling the [source code](https://github.com/grpc/grpc)
-- Create a simlink named `protoc-gen-grpc_python` to `grpc_python_plugin` using `ln -nsf $(which grpc_python_plugin) /some/where/in/your/path/protoc-gen-grpc_python`
 
 ### Flutter
 
 - Install the latest stable version of flutter
-- Run `flutter pub global activate protoc_plugin`
-- Add `$HOME/.pub-cache/bin` to `PATH`
 
 ### VS Code
 
@@ -36,9 +25,10 @@ This projects aims to offer a comprehensive guide to **record polysomnographic E
 ## Dev workflow
 
 - Open workspace `polydodo.code-workspace`
+- Install Python packages by running `pip install --user -r backend/requirements.txt`
 - Install node modules by running `yarn install --cwd web`
 - Fetch Flutter dependencies through the `Flutter` extension
-- Compile all protos through `proto3` extension
+- Start dev server by running `python backend/app.py`
 
 ## Running the server locally
 

backend/Dockerfile

@@ -1,18 +1,5 @@
-FROM namely/protoc-all as generator
-WORKDIR /
-COPY protos protos
-COPY backend backend
-RUN ln $(which grpc_python_plugin) /usr/bin/protoc-gen-grpc_python
-RUN protoc protos/* --python_out=backend --grpc_python_out=backend
-
-FROM envoyproxy/envoy:v1.15-latest
-RUN apt-get update \
-  && apt-get -y install python3-pip \
-  && apt-get autoremove -y \
-  && apt-get clean \
-  && rm -rf /tmp/* /var/tmp/* \
-  && rm -rf /var/lib/apt/lists/*
-COPY --from=generator /backend /backend
+FROM python
+COPY . /backend
 WORKDIR /backend
 RUN pip3 install -r requirements.txt --no-cache-dir
-CMD "./start.sh"
+CMD ["python", "app.py"]

backend/app.py

@@ -1,40 +1,14 @@
-# Copyright 2015 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-"""The Python implementation of the GRPC helloworld.Greeter server."""
+from flask import Flask
+from flask_cors import CORS
+from waitress import serve
 
-from concurrent import futures
-import logging
+app = Flask(__name__)
+cors = CORS(app)
 
-import grpc
 
-from protos import helloworld_pb2
-from protos import helloworld_pb2_grpc
+@app.route("/")
+def hello():
+    return "Hello, World!"
 
 
-class Greeter(helloworld_pb2_grpc.GreeterServicer):
-    def SayHello(self, request, context):
-        return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)
-
-
-def serve():
-    server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
-    helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
-    server.add_insecure_port('[::]:9090')
-    server.start()
-    server.wait_for_termination()
-
-
-if __name__ == '__main__':
-    logging.basicConfig()
-    serve()
+serve(app, host='0.0.0.0', port=8080)

backend/requirements.txt

@@ -1,2 +1,3 @@
-grpcio==1.32.0
-protobuf==3.13.0
+Flask==1.1.2
+Flask-Cors==1.10.3
+waitress==1.4.4

backend/setup.cfg

@@ -1,4 +1,4 @@
 [flake8]
 ignore = D203
-exclude = __pycache__,old,build,dist,backend/protos
+exclude = __pycache__,old,build,dist
 max-complexity = 10

mobile/lib/main.dart

@@ -1,26 +1,7 @@
-import 'package:polydodo/protos/helloworld.pbgrpc.dart';
-import 'package:grpc/grpc.dart';
 import 'package:flutter/material.dart';
 
-import 'protos/helloworld.pb.dart';
 import 'src/app.dart';
 
 void main() async {
-  // GRPC TEST
-  final channel = ClientChannel(
-    const String.fromEnvironment('HOST'),
-    port: 9090,
-    options: const ChannelOptions(credentials: ChannelCredentials.insecure()),
-  );
-  final stub = GreeterClient(channel);
-
-  try {
-    final response = await stub.sayHello(HelloRequest()..name = 'world');
-    print('Greeter client received: ${response.message}');
-  } catch (e) {
-    print('Caught error: $e');
-  }
-  await channel.shutdown();
-  // END OF TEST
   runApp(App());
 }