C4all

Comments for all is an easy to use comment field. Read more about it on the website.

Development setup

# prepare the virtual environment (requires virtualenvwrapper: http://virtualenvwrapper.readthedocs.org/en/latest/)
mkvirtualenv --no-site-packages c4all

# get c4all service
git clone [email protected]:c4all/c4all.git c4all
cd c4all

# set up the development environment
make dev-setup

# run c4all service
python manage.py runserver_plus

The production setup

The production environment can't be set up automatically (at it may require setting up database details and other per-server settings manually), but there are some helper Makefile tasks to speed it up.

To set up the production environment for c4all service, loosely follow this procedure:

# prepare the virtual environment (requires virtualenvwrapper: http://virtualenvwrapper.readthedocs.org/en/latest/)
mkvirtualenv --no-site-packages c4all

# get c4all service
git clone [email protected]:c4all/c4all.git c4all
cd c4all

# install the requirements
make reqs/prod

# Create a project/settings/local.py settings file with per-server config
# and import prod settings (write "from .prod import *" in the local.py file
# after you create it)
vim c4all/settings/local.py

# Setup your own DB. to connect c4all and your DB, refer to the settings
# part of this document and django docs (specifically https://docs.djangoproject.com/en/1.5/ref/databases/)

# Install Node.js and less compiler
* OS-specific Node.js installation: https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager/)
npm install -g less

# For spell checking abilities, you will need to install the enchant
# (http://www.abisource.com/projects/enchant/) library. For a specific
# language, take a look at the supported languages on the aspell website
# (http://aspell.net/man-html/Supported.html) and install it. The language
# set in the base settings (LANGUAGE_CODE variable) is what the spell
# checker is using for its operation. After installing enchant, install
# pyenchant by running:
pip install pyenchant==1.6.5

# Add or change setting SPELLCHECK_ENABLED in base.py:
SPELLCHECK_ENABLED = True

# Run automatic update (db sync/migrations, collectstatic)
make prod-update

# Create superuser (provide credentials: email and password)
python manage.py createsuperuser

# Your production environment is now ready
python manage.py run_gunicorn

# Set the BASE_URL in base.py to "http://www.your-server-address.com".

# The default language is Swedish, if you want to change it to English set
# the LANGUAGE_CODE variable in base.py to 'en_EN'.

# Head to the superadmin page at www.your-server-address.com/djadmin/,
# login with your superuser credentials and add a Site object in Sites by
# providing the URL of the site which will include the c4all widget.

# Include html snippets on your page:
<script src="{{ BASE_URL }}/static/js/comments.js" type="text/javascript"></script>
<div id="c4all-widget-container"></div>

# Article name handling is done via html tag reading. if the ID
# value "c4all-admin-page-title" is added to a html element, the script will read its'
# text value. If ID is not provided, the script will first try to read the page title,
# followed by the first h1 tag. If everything fails, the url path/location will be
# passed to the server.

# Start commenting!

Text-to-speech is possible via the commercial Readspeaker service (http://www.readspeaker.com/). After setting up a Readspeaker account, enter your ReadSpeaker Customer ID into rs_customer_id field of the Site object in the superadmin interface. Ensure that the domain where comments are displayed is the same as in the ReadSpeaker admin interface.

The development environment by default includes:

• South for database migrations (both development and production use it)
• Django Debug Toolbar for displaying extra information about view execution
• SQLite database (dev.db in the project root directory)
• Integrated view debugger making it easy to debug crashes directly from the browser (Werkzeug and django-extension's runserver_plus)
• Full SQL statement logging
• Beefed-up Django shell with model auto-loading and IPython REPL
• Flake8 source code checker (style, passive code analysis)
• Console E-mail backend set by default in dev for simple E-mail send testing
• Automated testing all set-up with nose, optionally creating test coverage reports, and using the in-memory SQLite database (and disabled South) to speed up test execution
• Disabled cache for easier debugging

The production environment by default includes:

• Gunicorn integration
• Django Compressor for CSS/JS asset minification and compilation
• Database auto-discovery via environment settings, compatible with Heroku
• Sentry client (raven_compat) for exception logging (used only if SENTRY_DSN variable is set in settings or environment)
• Local-memory cache (although memcached is strongly recommended if available)

The settings files

The settings files base (base settings used in all environments), prod (production settings), dev (local development settings) and test (settings used when running automated tests) should contain only the settings used by all developers/servers.

Per-server (or per-developer) settings should go into local module (ie. project/settings/local.py). The usual pattern for this module is to first import everything from the settings variant that best matches your environment (prod for servers, dev for local development), and then override/add settings as needed.

Example production settings just specifying the production database:

# file: project/settings/local.py
from .prod import *

DATABASES = {
    'default': { ... }
}

You shouldn't need to add local.py to the repository (in fact, git is already set up to ignore it). If some setting needs to be shared by everyone, it should probably be added to base, dev or prod.

The local settings file isn't required. If it doesn't exist, the production setup will be used by default. This is useful if you don't have per-server settings or they're deployed via Unix environment (as they are on eg. Heroku and similar cloud hosting providers). There is a sample local.py located in settings directory which hosts some of the commonly used variables.

Environment settings

Settings can also be set via the environment variables. The following variables are supported:

• DATABASE_URL - Heroku-compatible database URL
• DEBUG - String true enables DEBUG, any other disables
• TEMPLATE_DEBUG - String true enables TEMPLATE_DEBUG, any other disables
• COMPRESS_ENABLED - String true enables django-compressor, any other disables
• SQL_DEBUG - String true enables SQL statement logging, any other disables (disabled by default, available only if using dev.py)
• CACHE_BACKEND - String value to put into CACHES['default']['BACKEND']
• EMAIL_BACKEND - String value for EMAIL_BACKEND (only if using dev.py)

Note that values from local.py override environment settings! You probably want to use either the local settings file or the environment settings, not mix them.

The extended tour

After setting up your new c4all project, try these:

# make sure all tests pass
make test

# get a test coverage report (outputs to stdout, saves HTML format in
# cover/index.html and produces Cobertura report compatible with Jenkins)
make coverage

# clean up test artifacts, *.pyc files and cached compressed assets
make clean

# check if the code follows PEP8 and is free of obvious errors
# this also includes cyclomatic complexity check and will complain if your
# code is too complex (configurable by editing the Makefile)
make lint

# update the environment (eg. after pulling in new code)
make dev-update

# open up the new and improved Django shell
python manage.py shell_plus

Heroku support

To specify Python module dependencies on Heroku, add a pip requirements file named requirements.txt to the root of your repository. Since c4all has python dependencies distributed in more files, you'll have to call the production requirements file from the main requirements file you just created:

git checkout -b heroku
echo "-r requirements/prod.txt" > requirements.txt
git add requirements.txt
git commit -m 'requirements for heroku'

The production setup uses database autodiscovery so if you have a (promoted) database in Heroku, it will automatically get picked up.

For Heroku, you'll probably want to add a Procfile file with contents similar to this:

web: python manage.py run_gunicorn --workers=4 --bind=0.0.0.0:$PORT

If your web app supports uploading of media (eg. images, videos or other files) by users, you'll probably need the django-storages app to automatically host them somewhere else (eg on Amazon S3). When django-storages is set up, the collecstatic management command (run as part of make prod-update) will copy the static assets to the specified service as well.

After pushing the new code to Heroku for update, you should make sure to run all the needed management commands to migrate the database, etc:

heroku run make prod-update

Sentry / Raven

To use the Sentry client, you'll need a server to point it to. Installing Sentry server is easy as:

# mkvirtualenv --no-site-packages sentry-env
# pip install sentry
# sentry init
# sentry start

You'll want to install Sentry into its own environment as it requires Django 1.2 or 1.3 at the moment.

If you don't want to install Sentry yourself, you can use a hosted version at http://getsentry.com/.

When you connect to your (or hosted) Sentry server and create a new project there, you'll be given Sentry DSN which you need to put into production settings to activate Sentry exception logging.

Deployments via git

If deployments are done via git (and not fabric, see below), it's recommended to create another Makefile target that will do the deploy, for example:

deploy:
  git pull
  $(MAKE) update
  # command to restart the service(s) as neccessary

Fabric

A fabfile is provided with common tasks for rsyncing local directory to the server for use while developing the project, and for deploying the project using git clone/pull.

Useful commands:

• server - host to connect to (same as -H, but accepts only one argument)
• env - virtualenv name on the server, as used with virtualenvwrapper/workon
• project_path - full path to the project directory on the server
• rsync - use rsync to copy the local folder to the project directory on the server
• setup - set up the project instance on the server (clones the origin repository, creates a virtual environment, initialises the database and runs the tests)
• deploy - deploy a new version of project on the server using git pull
• collecstatic, syncdb, migrate, runserver - run manage.py command
• update - combines collecstatic, syncdb, migrate
• test - run manage.py test with the test settings enabled

For all the commands, run 'fab -l' or look at the source.

Examples:

Copy local directory to the server, update database and static files, and run tests (only files changed from last copy are going to be copied):

fab server:my.server.com env:myenv project_path:/path/to/project rsync update test

Deploy a new instance of a project on a server ('myenv' will be newly created, code will be cloned into /path/to/project):

fab server:my.server.com env:myenv project_path:/path/to/project \
    setup:origin=http://github.com/your/repo

Deploy a new version of the project on the server (a new git tag will be created for each deployment, so it's easy to roll-back if needed):

fab server:my.server.com env:myenv project_path:/path/to/project deploy

Customization

Everyone has a slightly different workflow, so you'll probably want to customize the default fabric tasks or combine them. You can either customize fabfile.py and commit the changes to your repository, or you can create local_fabfile.py, which will be loaded if it exists. The latter can be useful if you have per-team-member fabric customizations you don't want to commit to the repository.