Commit v0.5

v0.5 - AppConfig: DevelopmentConfig, TestingConfig, ProductionConfig, ENV FLASK_CONFIG

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Files changed (4)

• +6 -1 [M] web/Dockerfile
• +4 -4 [M] web/app/init.py
• +25 -0 [M] web/config.py
• +4 -3 [M] web/flaskapp.py

File web/Dockerfile MODIFIED

• Update comments.
• Add FLASK_CONFIG environment variable.

 # base container image
 FROM python:3.6.1-alpine
 
-# add tzdata to base image; set timezone environment variable
+# update system packages
 RUN apk add --no-cache tzdata
+
+# set environment variables for system
 ENV TZ America/Los_Angeles
 
+# set environment variables for application
+ENV FLASK_CONFIG development
+
 # setup working directory within container
 RUN mkdir -p /web
 WORKDIR /web

File web/app/init.py MODIFIED

• Replace direct use of AppConfig with reference to a config subclass DevelopmentConfig, TestingConfig or ProductionConfig.

 from flask import Flask
-from config import AppConfig
+from config import config
 
-def create_app():
+def create_app(config_name):
     app = Flask(__name__)
 
-    app.config.from_object(AppConfig)
-    AppConfig.init_app(app)
+    app.config.from_object(config[config_name])
+    config[config_name].init_app(app)
 
     return app

File web/config.py MODIFIED

• Create subclasses of AppConfig corresponding to different deployment environments.
• DevelopmentConfig and TestingConfig contain single values for now.
• ProductionConfig contains a placeholder init_app() method.
• Create config dictionary to map FLASK_CONFIG values to objects.

     @staticmethod
     def init_app(app):
         pass
+
+
+class DevelopmentConfig(AppConfig):
+    DEBUG = True
+
+class TestingConfig(AppConfig):
+    TESTING = True
+
+
+class ProductionConfig(AppConfig):
+    DEBUG = False
+    TESTING = False
+
+    @classmethod
+    def init_app(cls, app):
+        # multi-step setups could go here
+        AppConfig.init_app(app)
+
+
+config = {
+    'development': DevelopmentConfig,
+    'testing':     TestingConfig,
+    'production':  ProductionConfig,
+    'default':     DevelopmentConfig
+}

File web/flaskapp.py MODIFIED

• Pass the environment value FLASK_CONFIG through to app.create_app().
• Update the route /info/config to display the value of FLASK_CONFIG.

-app = create_app()
+app = create_app(os.getenv('FLASK_CONFIG') or 'default')
... 
 @app.route('/info/config')
 def app_config():
     cnf = dict(app.config)
-    return "Current Config : %s" % cnf
+    return "'%s' Config : %s" % (os.getenv('FLASK_CONFIG'),cnf)

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Commit-v0.4 | Commit-v0.5 | Commit-v0.6