BOTTLEPLATE

bottleplate is a bottle template for python 3.3+ web applications or API servers. The files structure is very similar to that of a Ruby on Rails application and thus follows a model-view-controller (MVC) pattern. It provides a simple way to have development, test and production environments. The structure for functional and unit testing is also already in place. It is very common for bottle applications to define routes using the bottle route decorator. However, I find it more convenient to have all routes defined in a file. This template uses bottleplate/config/routes.py for that. SQLAlchemy is used as the object relational mapping (ORM) tool. It supports a broad range of database backends (MySQL, PostgreSQL, SQLite, ...) and is usually the ORM of choice when it comes to python. alembic is used to handle database migrations so it takes care of the changes regarding the database schemas.

Sounds interesting? If you still have questions after having read this readme file, feel free to contact me (either by email or IRC at #gwcomputingnet on Freenode).

Need to have a look at a concrete examples? Have a look at pydeo to see a usage of this template for a web application and devmine-core to see an example usage of this template for an API server.

WHAT IS INCLUDED ?

Not much actually since this is not a framework but just a template. However, it assumes some choices such as:

• bottle, the minimalist python web framework
• SQLAlchemy as the ORM of choice
• alembic for handling database migrations
• invoke as the task execution tool
• nose for unit testing
• WebTest for functional testing
• pep8 to check source code conformance to pep8 style conventions
• flake8 to scan python source code for errors

Of course, nothing is written into stone and you can adapt the template to your needs.

FILES STRUCTURE AND ORGANIZATION

ROOT DIRECTORY

The root directory contains two folders and some files:

• alembic.ini.sample: this is a template file for alembic.ini. It is copied to alembic.ini when invoke setup is run.
• bottleplate: this is where lays your bottle application.
• env: this folder is used for the python virtual environment.
• requirements.txt: this file defines the prerequisite packages to run the application.
• requirements_dev.txt: this file defines the prerequisite packages needed to develop the application or contribute to the project.
• run.py: this script is used to run the application.
• tasks.py: this is where you can define tasks. In some ways, this is similar to UNIX Makefiles.

THE APPLICATION DIRECTORY

• app: is used to organize your application contents such as controllers, static assets, models and views.
• app/controllers: this is where lay the application controllers.
• app/helpers: this is where helper classes are defined.
• app/models: this is where the application models are defined, using SQLAlchemy.
• app/views: this is where the HTML template files are. The basic bottleplate uses the SimpleTemplate, which is a very simple template engine shipped with bottle but of course, other template engines such as Mako may be used instead.
• app/views/layouts: this is where you define the base layout templates to be used with views.
• config: the configuration files lay there.
• config/environments: this is where you define the specific environment settings for development, test or production.
• config/routes.py: this is where you define your routes and associate them to the appropriate controllers.
• db: if you use a SQLite database, you will find the database file here. This folder is also used by alembic to store the database migration scripts.
• lib: if you need to write libraries, you would place them here.
• log: this is where the log files should go.
• test: this folder is meant to hold the test files.
• test/functional: this is where you write functional tests.
• test/unit: this is where you write unit tests.

PREDEFINED TASKS

Some tasks are already defined in the tasks.py file.

• set_settings: this task is used to copy the default configuration file from from the templates. Basically, it copies the settings-{environment}.py file to settings.py where {environment} is one of development | production | test. Example: invoke set_settings --environment=production
• dev: run the application.
• test_func: run the functional tests.
• test_unit: run the unit tests.
• test: run both the functional and unit tests.
• setup: copy the setting files and alembic sample files from their templates.
• pep8: check source code compliance to PEP8.
• flake8: check source code for errors.
• check run both the pep8 and flake8 tasks.
• clean: clean any python generated files and folders.
• clean_env: run the clean tasks and reinitializes the python environment.
• rename: this is supposed to be used only once. It rename the bottleplate directory and replaces bottleplate and Bottleplate names in python sources where appropriate. If you provide a name like this one: my awesome app, occurences of bottleplate will be replaced by myawesomeapp and occurences of Bottleplate by MyAwesomeApp.

SETTING THE WHOLE THING

Make sure you have python 3.3 or above and virtualenv. Follow these steps:

• create the virtual environment: virtualenv -p python3 env
• activate the environment: source env/bin/activate
• install the required packages through pip: pip install -r requirements.txt -r requirements_dev.txt

From now on, you also need to choose which web server backend you are willing to use with bottle. Have a look here for the full list of servers supported by bottle but keep in mind that not all of them are compatible with python3. Let's assume that your choice is cherrypy (which is the server set by default in this template but you can easily change that). Then, what you would do is make sure that in bottleplate/config/environments/(development|production|test).py, server is set to cherrypy: server = 'cherrypy'. Maybe, it is OK to keep the simple wsgiref server for testing so you would simple set it to this wsgiref for the test environment. Of course, you then need to install the server backend: pip install cherrypy.

Now that you have a web server backend, you also need to choose a database backend. Let's assume that you choose to use sqlite as test and development databases and postgresql for production. The you need to change db_url in the respective files like, for instance:

• development.py: db_url = 'sqlite:///bottleplate/db/dev.db'
• production.py: db_url = 'postgresql://user:pass@localhost/dbname'
• test.py: db_url = 'sqlite:///:memory:'

Of course, you might need additional packages to support the database backend. For instance, if you use postgresql, you need psycopg2.

To use the migration, you also need to provide the appropriate database URL in the alembic.ini file. Have a look at alembic documentation for more information.

Once all of this is setup, you can rename the template using this command: invoke rename --name='my awesome app name'. Of course, replace the name by the appropriate one. You may want to remove the template under views if you are creating an API server.

RUN IT

Considering all has been setup, you can run your application using this command:

python run.py

Or using invoke:

invoke dev

You can now navigate to http://localhost:8080 (considering you haven't changed the default port) and see a sample home page.