The document discusses bootstrapping Django projects with ease. It introduces djenesis, a tool created by Concentric Sky to simplify starting new Django projects and setting up existing projects. Djenesis encourages best practices like using virtualenv and standard project structures. It allows importing external templates from Git, Mercurial, or Subversion to version control project templates.
4. (Some) Technologies We Use
• Chef • Backbone.js
• Jenkins • Jinja2
• AWS • Celery
• Sphinx • DebugToolbar
• Memcached • jQuery / jQueryUI
• South • Compass / Sass
• git • Mongo & MySQL
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5. Released CSky Creations
• djenesis – Easy Django Bootstrapping
• breakdown - Lightweight jinja2 template
prototyping server
• django-cachemodel – Automatic caching
for django models
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6. CSky Creations in the Works
• skycloud – Tool for AWS auto-scaling
• django-skycms – CMS as a library
• django-sky-visitor – Invitations, email
confirmation, etc
• django-client-admin – Flexible admin for
client
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7. CSky Teams
10 Django Team
STAFF
50+
5 Design Team
9 PM Team
3 System Admins
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8. Team Interfacing
• Each project is a mix from each team
• Members might switch amongst projects
• Interfaces between teams
• Clean separation of handoffs and
responsibilities
• Best-practices shared within teams
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9. “Bootstrapping”
• Pulling one up by one’s bootstraps
• Computers do this much better than humans
• Django – starting a project, new or existing
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10. Bootstrapping with Ease
Making booting (and rebooting) a
django project as easy as possible
• Ease is a continually moving target
• Shouldn’t sacrifice other goals for ease (e.g.
security, modularity, be PHP)
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11. Moving Targets
Moving targets create new
problems. And new solutions.
• CGI – Solving static HTML
• JavaScript – Solving non-interactivity
• CSS – Solving 100+ HTML pages
• Puppet/Chef – Solving 100+ servers
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12. Problem/Solution Lifecycle
1. Problem grows
2. Many create their own solution; some
polish; some release
3. Community flocks to one (or a few) solutions
4. Solution(s) gets anointed and others die off
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13. Goals of Easy Bootstrapping
1. More people using Django
2. More people using Django better
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14. More People Using Django
• As few commands as possible to try
Django out
• And to try someone else’s project out.
• Must be highly likely to just work
• All especially critical for beginners
• Django’s runserver & sqlite...great!
• It just works...
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15. Making Mistakes should be Hard
• Checklists are great
• The best checklists
are invisible
• To automate lists of
commands, must
have consistency
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16. Consistency Makes things Easier
• Ease of replication across servers
• Ease of sharing
• Both templates and existing projects
• Easier to build upon
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17. Consistently Standardized
• Standardization: a tool to get to
consistency
• This can be in an organization. Or the full
community
• Oh yeah, and...
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19. Fragmentation
• Poor standards lead to fragmentation
• Hard to build things on top of
fragmented environments
• Imagine building for single browser. Not
Mosaic.
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20. Android Fragmentation
http://www.businessinsider.com/android-fragmentation-chart-from-opensignalmaps-2012-5
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21. Flexibility vs Standardization
• Standardization can be rigid; can kill flexibility
• Especially as the target moves
• E.g. contrib.auth
• Flexibility allows preference, innovation
• Best of both worlds is standardization with
structured options of flexibility
• Django does this well
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22. Django
• Django is a set of higher-order building blocks
• If blocks are too large, sacrifices what can be
made (i.e. not flexibile)
• If blocks are too small, becomes inefficient
and unmanageable
• If block types are wrong, not loosely
coupled (i.e. non-orthogonal)
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23. 3 Stages of Project
Structure Grief
• Denial
• Bargaining
• Acceptance
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24. Denial
I’ll just take the
easy way out...
• Stuff required libraries in a ‘lib’ directory
• Stick django there too
• Name everything MyProjectSomething
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25. Denial
I’ll just take the easy way out...
Why this doesn’t work
• project starts to get bloated
• version management becomes a headache
• upgrade paths become tangled
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26. Bargaining
We’ll just adopt some
standard practices...
1. Have the team argue about which way to do things
2. Assign someone to write a document about it
3. ???
4. Ignore it when you start a new project
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27. Bargaining
We’ll just adopt some standard practices...
Why this doesn’t work
• Projects become inconsistent
• It is not in source control
• No way to manage changes across projects
• There is no history of changes or discussion
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28. Acceptance
Embrace the community
• requirements.txt, version management
• also solves the ‘git submodule’ problem
• virtualenv is great, always use it
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29. Acceptance
No, really, use virtualenv
• dependency management
• concurrent project management
• sand-boxing
• solves the “chicken-n-egg” problem
• replication
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30. What’s in a template?
• For a django project, there are two styles:
1. toplevel directory is python code
2. toplevel directory is a website project
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31. Toplevel is python code
./manage.py
./my_project/__init__.py
• Pros
./my_project/settings.py
./my_project/urls.py
• More pythonic; Everything
./my_project/wsgi.py
is python code
Django’s default template • It just works
• Cons
• Everything is python code
• Where do non public files
go?
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32. Default Django Project
./manage.py
./my_project/__init__.py
./my_project/settings.py
• Where do apps go?
./my_project/urls.py
./my_project/wsgi.py • How about ./my_project/
./my_project/my_app/__init__.py my_app/?
./my_project/my_app/models.py
• Name then becomes
‘my_project.my_app’
• What about reusability?
• What if I want to rename
my_project?
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33. Default Django Project
./manage.py
./my_project/__init__.py
./my_project/settings.py
• Where do apps go?
./my_project/urls.py
./my_project/wsgi.py • How about ./my_app/?
• Better for reusability, but...
./my_app/__init__.py
./my_app/models.py
• Now I have to add ./ to the
PYTHON_PATH
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34. Default Django Project
./manage.py
./myapp1/models.py
./myapp1/urls.py
• What was the name
./myapp2/models.py again?
• Was it ‘myapp1’ or ‘myapp2’
./myapp2/urls.py
./myapp3/models.py
./myapp3/urls.py that contains the main urls
and settings...
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35. Toplevel is website project
• Pros
./manage.py
./wsgi.py
./requirements.txt
• Closer to real world
./apps/mainsite/__init__.py
./apps/mainsite/settings.py
./apps/mainsite/settings_local.py
./apps/mainsite/urls.py environments
./apps/my_app/models.py
• Consistency across
./apps/my_app/urls.py
projects
• Cons
• ??? None I guess!
http://github.com/concentricsky/djenesis-template.git
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36. Toplevel is website project
./manage.py
./wsgi.py
./requirements.txt
./apps/mainsite/__init__.py
./apps/mainsite/settings.py
./apps/mainsite/settings_local.py.example
./apps/mainsite/urls.py
./apps/my_app/models.py
./apps/my_app/urls.py
Python code is sandboxed
• only have to add ./apps to PYTHON_PATH
• everything else is ignored by WSGI server
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37. Toplevel is website project
./manage.py
./wsgi.py
./requirements.txt
./apps/mainsite/__init__.py
./apps/mainsite/settings.py
./apps/mainsite/settings_local.py.example
./apps/mainsite/urls.py
./apps/my_app/models.py
./apps/my_app/urls.py
Consistent Entry Point Name
• I always know where to look first: ./apps/
mainsite/urls.py
• More important than it may seem at first blush
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38. Toplevel is website project
./manage.py
./wsgi.py
./requirements.txt
./apps/mainsite/__init__.py
./apps/mainsite/settings.py
./apps/mainsite/settings_local.py.example
./apps/mainsite/urls.py
./apps/my_app/models.py
./apps/my_app/urls.py
settings_local
• Loaded after settings.py as overrides.
• Easily set up a local development environment.
• Production credentials are at no risk.
• Easily deploy devel, staging, production stacks.
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39. Toplevel is website project
./manage.py
./wsgi.py
./requirements.txt
./apps/mainsite/__init__.py
./apps/mainsite/settings.py
./apps/mainsite/settings_local.py.example
./apps/mainsite/urls.py
./apps/my_app/models.py
./apps/my_app/urls.py
I have requirements.txt
• Library dependencies and versioning is simple.
• New developers can start working quicker.
• Simple virtualenv integration
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40. Okay, but now what?
1. Install and use virtualenv
2. Design and use a template
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43. Our approach
Djenesis: our solution to the
bootstrapping problem
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44. djenesis
• What is it?
• A tool that facilitates the process of
creating new and setting up existing Django
projects.
• Available on github & PyPi (apache license)
• github.com/concentricsky/djenesis
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45. djenesis - Benefits
• Simplifies routine workflows for:
• Starting a new project
• Getting an existing project up and running with ease
• Encourages developers to use a standard project
structure and best python practices (virtualenv)
• Allows external project templates
• Supports git, svn, hg URLs
• Supports Django 1.4 project templates
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46. djenesis - History
1. Single zip file of a stub project
2. Script that wrapped stub
3. Decouples templates from script
4. Can use external templates, git URL
5. Now: supports Django 1.4 templates
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47. djenesis - External Templates
• Inflating a project from a git/svn/hg source
means you can (and should) version
control your project templates
• Collaborate with your internal teams on an
ideal project structure
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49. djenesis - Setup
• Requires virtualenv
• Install virtualenv through pip or easy_install
• Install djenesis through pip or easy_install
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52. djenesis - Configuration
• Use a default template
DJENESIS_DEFAULT_TEMPLATE=/path/to/template
• Always use virtualenvwrapper (if installed)
DJENESIS_VIRTUALENVWRAPPER=1
• Set these in your .bashrc
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53. djenesis – Next?
1. startapp template in project template
2. setup.py Support
3. djenesis post-create hooks for common tasks
(copy local settings, syncdb, import fixtures)
4. Activate virtualenv when djenesis is called
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54. Bootstrapping
Django with ease
OSCON 2012
www.concentricsky.com
@concentricsky // biglan / wiggins / bothun
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