Merge pull request #11 from JoMingyu/issue/4

Flask Large Application Example 적용

app/__init__.py

@@ -0,0 +1,39 @@
+from flask import Flask
+from werkzeug.exceptions import HTTPException
+
+from app.misc.log import log
+
+
+def register_extensions(flask_app: Flask):
+    pass
+
+
+def register_views(flask_app: Flask):
+    from app.views import route
+
+    route(flask_app)
+
+
+def register_hooks(flask_app: Flask):
+    from app.hooks.error import broad_exception_handler, http_exception_handler
+    from app.hooks.request_context import after_request
+
+    flask_app.after_request(after_request)
+    flask_app.register_error_handler(HTTPException, http_exception_handler)
+    flask_app.register_error_handler(Exception, broad_exception_handler)
+
+
+def create_app(*config_cls) -> Flask:
+    log(message='Flask application initialized with {}'.format(', '.join([config.__name__ for config in config_cls])),
+        keyword='INFO')
+
+    flask_app = Flask(__name__)
+
+    for config in config_cls:
+        flask_app.config.from_object(config)
+
+    register_extensions(flask_app)
+    register_views(flask_app)
+    register_hooks(flask_app)
+
+    return flask_app

app/context.py

@@ -0,0 +1,18 @@
+from flask import current_app, request
+
+
+class _ContextProperty:
+    @property
+    def secret_key(self) -> str:
+        return current_app.secret_key
+
+    @property
+    def user_agent(self) -> str:
+        return request.headers['user_agent']
+
+    @property
+    def remote_addr(self) -> str:
+        return request.remote_addr
+
+
+context_property = _ContextProperty()

app/hooks/error.py

@@ -0,0 +1,9 @@
+from werkzeug.exceptions import HTTPException
+
+
+def http_exception_handler(e: HTTPException):
+    return '', e.code
+
+
+def broad_exception_handler(e: Exception):
+    return '', 500

app/hooks/request_context.py

@@ -0,0 +1,9 @@
+from flask import Response
+
+
+def after_request(response: Response) -> Response:
+    try:
+        response.headers['X-Content-Type-Options'] = 'nosniff'
+        response.headers['X-Frame-Options'] = 'deny'
+    finally:
+        return response

app/misc/log.py

@@ -0,0 +1,12 @@
+from termcolor import colored
+
+
+def log(message: str, keyword: str="WARN"):
+    if keyword == "WARN":
+        print(colored('[WARN]', 'yellow'), message)
+    elif keyword == "ERROR":
+        print(colored('[ERROR] ' + message, 'red'))
+    elif keyword == "INFO":
+        print(colored('[INFO]', 'blue'), message)
+    else:
+        print(colored('[{}]'.format(type), 'cyan'), message)

app/views/__init__.py

@@ -0,0 +1,25 @@
+from flask import Blueprint, Flask
+from flask_restful import Api
+
+
+def route(flask_app: Flask):
+    from app.views.sample import sample
+
+    handle_exception_func = flask_app.handle_exception
+    handle_user_exception_func = flask_app.handle_user_exception
+    # register_blueprint 시 defer되었던 함수들이 호출되며, flask-restful.Api._init_app()이 호출되는데
+    # 해당 메소드가 app 객체의 에러 핸들러를 오버라이딩해서, 별도로 적용한 handler의 HTTPException 관련 로직이 동작하지 않음
+    # 따라서 두 함수를 임시 저장해 두고, register_blueprint 이후 함수를 재할당하도록 함
+
+    # - blueprint, api object initialize
+    api_v1_blueprint = Blueprint('api_v1', __name__, url_prefix='/api/v1')
+    api_v1 = Api(api_v1_blueprint)
+
+    # - route
+    api_v1.add_resource(sample.Sample, '/sample')
+
+    # - register blueprint
+    flask_app.register_blueprint(api_v1_blueprint)
+
+    flask_app.handle_exception = handle_exception_func
+    flask_app.handle_user_exception = handle_user_exception_func

app/views/base.py

@@ -0,0 +1,10 @@
+import arrow
+from flask_restful import Resource
+
+
+class BaseResource(Resource):
+    def __init__(self):
+        self.utcnow = arrow.utcnow()
+        self.kstnow = self.utcnow.to('Asia/Seoul')
+        self.iso8601_formatted_utcnow = self.utcnow.isoformat()
+        self.iso8601_formatted_kstnow = self.kstnow.isoformat()

app/views/sample/sample.py

@@ -0,0 +1,10 @@
+from flask import request
+
+from app.views.base import BaseResource
+
+
+class Sample(BaseResource):
+    def post(self):
+        payload = request.json
+
+        return payload, 201

config/app_config.py

@@ -0,0 +1,9 @@
+import os
+
+
+class LocalLevelConfig:
+    SECRET_KEY = os.getenv('SECRET_KEY', '85c145a16bd6f6e1f3e104ca78c6a102')
+
+
+class ProductionLevelConfig:
+    SECRET_KEY = os.getenv('SECRET_KEY')

config/db_config.py

@@ -0,0 +1,6 @@
+class LocalDBConfig:
+    pass
+
+
+class RemoteDBConfig:
+    pass

constants/local_run.py

@@ -0,0 +1,6 @@
+RUN_SETTING = {
+    'host': 'localhost',
+    'port': 5000,
+    'debug': True,
+    'threaded': True
+}

production_app.py

@@ -0,0 +1,10 @@
+import os
+
+from app import create_app
+from config.app_config import ProductionLevelConfig
+from config.db_config import RemoteDBConfig
+
+if 'SECRET_KEY' not in os.environ:
+    raise Warning('The secret key must be passed by the <SECRET_KEY> envvar.')
+
+application = create_app(ProductionLevelConfig, RemoteDBConfig)

run.py

@@ -1,12 +1,9 @@
-from flask import Flask
-
-app = Flask(__name__)
-
-
-@app.route('/')
-def index():
-    return 'This is version 2'
+from app import create_app
+from config.app_config import LocalLevelConfig
+from config.db_config import LocalDBConfig
+from constants.local_run import RUN_SETTING
 
+app = create_app(LocalLevelConfig, LocalDBConfig)
 
 if __name__ == '__main__':
-    app.run()
+    app.run(**RUN_SETTING)