1. { Django Deployment Tips, Tricks and Best Practices Erik LaBianca, WiserTogether, Inc.

2.  You mission, should you choose to accept it:  Make your application run with 1 click, everywhere it counts, every time.  Make your application run exactly the same way, everywhere it counts, every time.  Prove that the above are true. Reproducibility

3.  Reproducible Infrastructure  Reproducible Systems  Reproducible [Django] Applications  Dependencies  Configuration  Data  Deployment Steps to Reproducibility

4.  Systems: Virtual or Physical  Power Management  Console  Backup / Restore  Network Layer  Load Balancing  Security  Performance Infrastructure

5.  A Stable Foundation  Stable Operating System  Reproducible Installation  Kickstart Install  Base Image  Configuration Management  Puppet, Chef  Packaging Systems

6.  What Python?  Database?  Backup / Restore  Failover  Performance  Caching?  HTTP  Objects  Queuing?  SSL? Application Environment

7.  It’s just code, right?  Probably Not Application

8.  Just use pip!  Not so fast.  Lots of external dependencies  Eliminate them with a local cache  Don’t’ forget virtualenv! Dependencies lib/pypi-cache: Django-1.4.3.tar.gz requirements.txt: Django==1.4.3 Type this: pip install --no-index --find-links file://$(PWD)/lib/pypi-cache -r requirements.txt

9.  settings.py  No logic allowed!  “unknown” import times  Critical  Local_settings.py  More of the same  Consider pushing configuration in externally via environ, configparser, etc Configuration settings.py: from urlparse import urljoin from os import environ import dj_database_url #courtesy of Heroku DATABASES = dj_database.config(default=“xxx”) BASE_URL = environ[‘DJANGO_BASE_URL’] STATIC_URL = urljoin(BASE_URL, ‘static’) MEDIA_URL = urljoin(BASE_URL, ‘media’) Run this: DJANGO_BASE_URL=http://cdn.com/base/ django-admin.py runserverhttp://cdn.com/base/

10.  Fixtures. Consider writing them in Python!  Testable  More resilient to change  Less pk pain  Migrations!  Test them Database fixtures/polls.py: from..models import Poll, Choice def apply(): p = Poll.objects.get_or_create(q=‘test q’, defaults=dict(pub_date=‘1980-01-01)) c1 = Choices.objects.get_or_create(poll=p, choice_text=‘option 1’) fixtures/tests/test_poll.py: Class PollFixtureTestCase(TestCase): def test_fixture_applied(): self.assertEquals(Poll.objects.get(q=‘test q’)

11. management/__init__.py: from django.db.models.signals import post_syncdb from south.signals import post_migrate from.. import models, fixtures def update_poll_fixtures(verbose=True): fixtures.poll.apply() if verbose: print "Updating dynamic fixtures for profile” def update_fixtures_post_syncdb(sender, **kwargs): update_poll_fixtures() def update_fixtures_post_migrate(app, **kwargs): if app == ’polls': update_poll_fixtures() post_syncdb.connect(fixtures_post_syncdb, sender=models) post_migrate.connect(fixtures_post_migrate)

12.  Back Up Everything!  Move files to Green  Fabric?  RPM?  Tar?  Git?  Rsync?  Update Stuff  syncdb  apply fixtures  Test Green!  Flip/Flop Blue/Green  (Roll back to Blue) Deployment: Blue/Green Data App Interwebs Deploy / Test

13. Erik LaBianca, WiserTogether, Inc. erik.labianca@gmail.com@easelhttps://linkedin.com/in/eriklabianca/https://slideshare.net/easel1/https://github.com/easel/https://github.com/WiserTogether/ Questions?