Chapter 17: Heroku support with Waitress (17c-waitress)

Procfile

@@ -0,0 +1 @@
+web: waitress-serve --port=$PORT flasky:app

app/__init__.py

@@ -29,6 +29,10 @@ def create_app(config_name):
     login_manager.init_app(app)
     pagedown.init_app(app)
 
+    if app.config['SSL_REDIRECT']:
+        from flask_sslify import SSLify
+        sslify = SSLify(app)
+
     from .main import main as main_blueprint
     app.register_blueprint(main_blueprint)
 

config.py

@@ -13,6 +13,7 @@ class Config:
     FLASKY_MAIL_SUBJECT_PREFIX = '[Flasky]'
     FLASKY_MAIL_SENDER = 'Flasky Admin <flasky@example.com>'
     FLASKY_ADMIN = os.environ.get('FLASKY_ADMIN')
+    SSL_REDIRECT = False
     SQLALCHEMY_TRACK_MODIFICATIONS = False
     SQLALCHEMY_RECORD_QUERIES = True
     FLASKY_POSTS_PER_PAGE = 20
@@ -66,10 +67,30 @@ def init_app(cls, app):
         app.logger.addHandler(mail_handler)
 
 
+class HerokuConfig(ProductionConfig):
+    SSL_REDIRECT = True if os.environ.get('DYNO') else False
+
+    @classmethod
+    def init_app(cls, app):
+        ProductionConfig.init_app(app)
+
+        # handle reverse proxy server headers
+        from werkzeug.contrib.fixers import ProxyFix
+        app.wsgi_app = ProxyFix(app.wsgi_app)
+
+        # log to stderr
+        import logging
+        from logging import StreamHandler
+        file_handler = StreamHandler()
+        file_handler.setLevel(logging.INFO)
+        app.logger.addHandler(file_handler)
+
+
 config = {
     'development': DevelopmentConfig,
     'testing': TestingConfig,
     'production': ProductionConfig,
+    'heroku': HerokuConfig,
 
     'default': DevelopmentConfig
 }

requirements.txt

@@ -0,0 +1,3 @@
+# this requirements file is used by Heroku
+# requirements for other configurations are located in the requirements subdirectory
+-r requirements/heroku.txt

requirements/heroku.txt

@@ -0,0 +1,4 @@
+-r prod.txt
+Flask-SSLify==0.1.5
+waitress==1.0.2
+psycopg2==2.7.3