Implemented get_db for MySQL, wrapped all routes in classes

flaskapp/app.py

@@ -2,11 +2,21 @@
 
 import os
 import secrets
+from typing import Optional
+from typing import Type, List
 
 from flask import Flask
+from flaskext.mysql import MySQL  # type: ignore
 
-from . import routes
+from .routes import Routes
+from . import pages
 from . import errors
+from . import db
+
+routes: List[Type[Routes]] = [
+    pages.RoutePages,
+    errors.RouteErrors,
+]
 
 
 def create_app() -> Flask:
@@ -26,14 +36,45 @@ def create_app() -> Flask:
         secrets.token_hex(32),
     )
 
+    # Setup MySQL database
+    app.config.update({
+        'MYSQL_DATABASE_HOST': os.getenv('DB_HOST', 'localhost'),
+        'MYSQL_DATABASE_PORT': parseint(os.getenv('DB_PORT'), 3306),
+        'MYSQL_DATABASE_USER': os.getenv('DB_USER', 'root'),
+        'MYSQL_DATABASE_PASSWORD': os.getenv('DB_PASSWORD', ''),
+        'MYSQL_DATABASE_DB': os.getenv('DB_DATABASE', '${REPO_NAME_SNAKE}'),
+    })
+    sql = MySQL(app)
+    db.set_db(sql)
+
     # Create instance/ directory
     try:
         os.makedirs(app.instance_path)
     except OSError:
         pass
 
-    # Add routes
+    # Add all routes
-    routes.add_routes(app)
+    for r in routes:
-    errors.add_routes(app)
+        r(app).add_routes()
 
     return app
+
+
+def parseint(
+        value: Optional[str],
+        default: int) -> Optional[int]:
+    """Parses integer from the string,
+    returns default value on error
+
+    Args:
+        value (Optional[str]): String or None
+        default (int): Default value
+
+    Returns:
+        Integer or None
+    """
+
+    try:
+        return int(value or default)
+    except ValueError:
+        return default

flaskapp/db.py

@@ -0,0 +1,25 @@
+"""Simple wrapper for getting/setting
+db key in global Flask object called `g`"""
+
+from flask import g
+from flaskext.mysql import MySQL  # type: ignore
+
+
+def set_db(db: MySQL) -> None:
+    """Add the database to `g` object
+
+    Args:
+        db (MySQL): MySQL database
+    """
+
+    g.db = db
+
+
+def get_db() -> MySQL:
+    """Get the database from `g` object
+
+    Returns:
+        MySQL database
+    """
+
+    return g.db

flaskapp/errors.py

@@ -5,44 +5,43 @@ from pathlib import Path
 from flask import Flask
 from flask import render_template
 
+from . import routes
+
 # Add other HTTP error codes here
 CODES = [404, 500]
 
 
-def add_routes(app: Flask) -> None:
+class RouteErrors(routes.Routes):
-    """Add all error handlers
+    """Error handlers wrapped in Routes interface"""
 
-    Args:
+    def __init__(self, app: Flask) -> None:
-        app (Flask): Flask application
-    """
 
-    tmpl_dir = app.template_folder
+        super().__init__(app)
-    if tmpl_dir is None:
-        return
 
-    tmpl = Path(__file__).parent / tmpl_dir
+        tmpl_dir = self.app.template_folder
+        if tmpl_dir is None:
+            return
 
-    for code in CODES:
+        self.tmpl = Path(__file__).parent / tmpl_dir
-        add_handler(app, tmpl, code)
 
+    def add_routes(self) -> None:
+        """Add all error handlers"""
 
-def add_handler(
+        for code in CODES:
-        app: Flask,
+            self.add_handler(code)
-        tmpl: Path,
-        code: int) -> None:
-    """Add Flask app error handler.
-    Only for internal use
 
-    Args:
+    def add_handler(self, code: int) -> None:
-        app (Flask): Flask application
+        """Add Flask app error handler.
-        file (str): Template filename
+        Only for internal use
-        code (int): Error code
-    """
 
-    file = f'{code}.html'
+        Args:
+            code (int): HTTP error code
+        """
 
-    if (tmpl / file).exists():
+        file = f'{code}.html'
 
-        @app.errorhandler(code)
+        if (self.tmpl / file).exists():
-        def handler(_e):
+
-            return render_template(file), code
+            @self.app.errorhandler(code)
+            def handler(_e):
+                return render_template(file), code

flaskapp/pages.py

@@ -0,0 +1,15 @@
+"""Main Flask app routes"""
+
+from flask import render_template
+
+from . import routes
+
+
+class RoutePages(routes.Routes):
+    """Main Flask app routes"""
+
+    def add_routes(self) -> None:
+
+        @self.app.route('/')
+        def index():
+            return render_template('index.html')

flaskapp/routes.py

@@ -1,16 +1,22 @@
-"""Main Flask app routes"""
+"""Interface for all routes classes"""
+
+import abc
 
 from flask import Flask
-from flask import render_template
 
 
-def add_routes(app: Flask) -> None:
+class Routes(abc.ABC):
-    """Add main routes
+    """Flask app routes interface"""
 
-    Args:
+    def __init__(self, app: Flask) -> None:
-        app (Flask): Flask application
+        """Flask app routes
-    """
 
-    @app.route('/')
+        Args:
-    def index():
+            app (Flask): Flask application
-        return render_template('index.html')
+        """
+
+        self.app = app
+
+    @abc.abstractmethod
+    def add_routes(self) -> None:
+        """Add routes"""

pylintrc

@@ -64,7 +64,7 @@ max-parents=7
 max-public-methods=20
 max-returns=6
 max-statements=50
-min-public-methods=2
+min-public-methods=1
 
 [STRING]
 check-quote-consistency=no
@@ -144,6 +144,7 @@ good-names=i,
            j,
            k,
            f,
+           db,
            ex,
            Run,
            _

requirements.txt

@@ -1,2 +1,3 @@
 flask==2.2.2
+flask-mysql==1.5.2
 gunicorn==20.1.0