Streamline setup process and init code

app/__init__.py

@@ -14,10 +14,11 @@ from flask_sqlalchemy import SQLAlchemy
 from flask_hashids import Hashids
 
 
+docker_client = DockerClient.from_env()
+
 apifairy = APIFairy()
 assets = Environment()
 db = SQLAlchemy()
-docker_client = DockerClient()
 hashids = Hashids()
 login = LoginManager()
 ma = Marshmallow()
@@ -28,80 +29,129 @@ scheduler = APScheduler()
 socketio = SocketIO()
 
 
-# TODO: Create export for lemmatized corpora
-
-
 def create_app(config: Config = Config) -> Flask:
-    ''' Creates an initialized Flask (WSGI Application) object. '''
+    ''' Creates an initialized Flask object. '''
+
     app = Flask(__name__)
     app.config.from_object(config)
-    config.init_app(app)
+
+    _configure_logging(app)
+    _configure_middlewares(app)
+    _init_docker_client(app)
+    _init_extensions(app)
+    _register_blueprints(app)
+    _register_socketio_namespaces(app)
+    _register_db_event_listeners(app)
+
+    return app
+
+
+def _configure_logging(app: Flask):
+    from flask.logging import default_handler
+    from logging import Formatter, StreamHandler
+
+    log_date_format: str = app.config['NOPAQUE_LOG_DATE_FORMAT']
+    log_format: str = app.config['NOPAQUE_LOG_FORMAT']
+    log_level: str = app.config['NOPAQUE_LOG_LEVEL']
+
+    formatter = Formatter(fmt=log_format, datefmt=log_date_format)
+    handler = StreamHandler()
+    handler.setFormatter(formatter)
+    handler.setLevel(log_level)
+
+    app.logger.removeHandler(default_handler)
+    app.logger.addHandler(handler)
+
+
+def _configure_middlewares(app: Flask):
+    from werkzeug.middleware.proxy_fix import ProxyFix
+
+    if app.config['NOPAQUE_PROXY_FIX_ENABLED']:
+        app.wsgi_app = ProxyFix(
+            app.wsgi_app,
+            x_for=app.config['NOPAQUE_PROXY_FIX_X_FOR'],
+            x_host=app.config['NOPAQUE_PROXY_FIX_X_HOST'],
+            x_port=app.config['NOPAQUE_PROXY_FIX_X_PORT'],
+            x_prefix=app.config['NOPAQUE_PROXY_FIX_X_PREFIX'],
+            x_proto=app.config['NOPAQUE_PROXY_FIX_X_PROTO']
+        )
+
+
+def _init_docker_client(app: Flask):
+    registry: str = app.config['NOPAQUE_DOCKER_REGISTRY']
+    username: str = app.config['NOPAQUE_DOCKER_REGISTRY_USERNAME']
+    password: str = app.config['NOPAQUE_DOCKER_REGISTRY_PASSWORD']
+
     docker_client.login(
-        app.config['NOPAQUE_DOCKER_REGISTRY_USERNAME'],
-        password=app.config['NOPAQUE_DOCKER_REGISTRY_PASSWORD'],
-        registry=app.config['NOPAQUE_DOCKER_REGISTRY']
+        username,
+        password=password,
+        registry=registry
     )
 
+
+def _init_extensions(app: Flask):
+    from typing import Callable
+    from .daemon import daemon
+    from .models import AnonymousUser, User
+
+    is_primary_instance: bool = app.config['NOPAQUE_IS_PRIMARY_INSTANCE']
+    socketio_message_queue_uri: str = app.config['NOPAQUE_SOCKETIO_MESSAGE_QUEUE_URI']
+    login_user_loader_callback: Callable[[int], User | None] = lambda user_id: User.query.get(int(user_id))
+
     apifairy.init_app(app)
     assets.init_app(app)
     db.init_app(app)
     hashids.init_app(app)
     login.init_app(app)
+    login.anonymous_user = AnonymousUser
+    login.login_view = 'auth.login'
+    login.user_loader(login_user_loader_callback)
     ma.init_app(app)
     mail.init_app(app)
     migrate.init_app(app, db)
     paranoid.init_app(app)
-    scheduler.init_app(app)
-    socketio.init_app(app, message_queue=app.config['NOPAQUE_SOCKETIO_MESSAGE_QUEUE_URI'])  # noqa
-
-    from .models import AnonymousUser, User
-    login.anonymous_user = AnonymousUser
-    login.login_view = 'auth.login'
-    @login.user_loader
-    def load_user(user_id):
-        return User.query.get(int(user_id))
-
     paranoid.redirect_view = '/'
+    scheduler.init_app(app)
+    if is_primary_instance:
+        scheduler.add_job('daemon', daemon, args=(app,), seconds=3, trigger='interval')
+    socketio.init_app(app, message_queue=socketio_message_queue_uri)
 
-    from .models.event_listeners import register_event_listeners
-    register_event_listeners()
 
+def _register_blueprints(app: Flask):
     from .admin import bp as admin_blueprint
-    app.register_blueprint(admin_blueprint, url_prefix='/admin')
-
     from .api import bp as api_blueprint
-    app.register_blueprint(api_blueprint, url_prefix='/api')
-
     from .auth import bp as auth_blueprint
-    app.register_blueprint(auth_blueprint)
-
     from .contributions import bp as contributions_blueprint
-    app.register_blueprint(contributions_blueprint, url_prefix='/contributions')
-
     from .corpora import bp as corpora_blueprint
-    from .corpora.cqi_over_sio import CQiNamespace
-    app.register_blueprint(corpora_blueprint, cli_group='corpus', url_prefix='/corpora')
-    socketio.on_namespace(CQiNamespace('/cqi_over_sio'))
-
     from .errors import bp as errors_bp
-    app.register_blueprint(errors_bp)
-
     from .jobs import bp as jobs_blueprint
-    app.register_blueprint(jobs_blueprint, url_prefix='/jobs')
-
     from .main import bp as main_blueprint
-    app.register_blueprint(main_blueprint, cli_group=None)
-
     from .services import bp as services_blueprint
-    app.register_blueprint(services_blueprint, url_prefix='/services')
-
     from .settings import bp as settings_blueprint
-    app.register_blueprint(settings_blueprint, url_prefix='/settings')
-
     from .users import bp as users_blueprint
-    app.register_blueprint(users_blueprint, cli_group='user', url_prefix='/users')
-
     from .workshops import bp as workshops_blueprint
+
+    app.register_blueprint(admin_blueprint, url_prefix='/admin')
+    app.register_blueprint(api_blueprint, url_prefix='/api')
+    app.register_blueprint(auth_blueprint)
+    app.register_blueprint(contributions_blueprint, url_prefix='/contributions')
+    app.register_blueprint(corpora_blueprint, cli_group='corpus', url_prefix='/corpora')
+    app.register_blueprint(errors_bp)
+    app.register_blueprint(jobs_blueprint, url_prefix='/jobs')
+    app.register_blueprint(main_blueprint, cli_group=None)
+    app.register_blueprint(services_blueprint, url_prefix='/services')
+    app.register_blueprint(settings_blueprint, url_prefix='/settings')
+    app.register_blueprint(users_blueprint, cli_group='user', url_prefix='/users')
     app.register_blueprint(workshops_blueprint, url_prefix='/workshops')
 
-    return app
+
+def _register_socketio_namespaces(app: Flask):
+    from .corpora.cqi_over_sio import CQiOverSocketIO
+
+    socketio.on_namespace(CQiOverSocketIO('/cqi_over_sio'))
+
+
+def _register_db_event_listeners(app: Flask):
+    from .models.event_listeners import register_event_listeners
+
+    register_event_listeners()

app/corpora/cqi_over_sio/__init__.py

@@ -19,7 +19,7 @@ This package tunnels the Corpus Query interface (CQi) protocol through
 Socket.IO (SIO) by tunneling CQi API calls through an event called "exec".
 
 Basic concept:
-1. A client connects to the "/cqi_over_sio" namespace.
+1. A client connects to the namespace.
 2. The client emits the "init" event and provides a corpus id for the corpus
    that should be analysed in this session.
      1.1 The analysis session counter of the corpus is incremented.
@@ -28,14 +28,13 @@ Basic concept:
      1.4 Connect the CQiClient to the server.
      1.5 Save the CQiClient, the Lock and the corpus id in the session for
          subsequential use.
-2. The client emits the "exec" event provides the name of a CQi API function
-   arguments (optional).
-     - The event "exec" handler will execute the function, make sure that the
-       result is serializable and returns the result back to the client.
-4. Wait for more events
-5. The client disconnects from the "/cqi_over_sio" namespace
-     1.1 The analysis session counter of the corpus is decremented.
-     1.2 The CQiClient and (Mutex) Lock belonging to it are teared down.
+3. The client emits "exec" events, within which it provides the name of a CQi
+   API function and the corresponding arguments.
+     3.1 The "exec" event handler will execute the function, make sure that
+         the result is serializable and returns the result back to the client.
+4. The client disconnects from the namespace
+     4.1 The analysis session counter of the corpus is decremented.
+     4.2 The CQiClient and (Mutex) Lock belonging to it are teared down.
 '''
 
 CQI_API_FUNCTION_NAMES: List[str] = [
@@ -86,7 +85,7 @@ CQI_API_FUNCTION_NAMES: List[str] = [
 ]
 
 
-class CQiNamespace(Namespace):
+class CQiOverSocketIO(Namespace):
     @socketio_login_required
     def on_connect(self):
         pass

app/daemon/__init__.py

@@ -1,5 +1,5 @@
-from app import db
 from flask import Flask
+from app import db
 from .corpus_utils import check_corpora
 from .job_utils import check_jobs