OpenStack is an open source stack that can be deployed on raw computing resources to privately or publicly present Infrastructure as a Service. It now consists of more than 4.5 million lines of code, 85% of which is Python. In this talk, Thierry Carrez and Doug Hellmann, both Python Software Foundation fellows and OpenStack Technical Committee members, look at the symbiotic relationship between OpenStack and Python. We go back in history and explain why OpenStack originally picked Python as its main language 6 years ago, and explore what does Python bring to OpenStack. We dive into examples of OpenStack pushing Python libraries to their limits and exposing new bugs. We look into the massive cloud-based continuous integration system that OpenStack uses and explain how it exposes bugs in Python libraries in the minutes after they are published to PyPI. We look into Python libraries that were created by the OpenStack community and libraries that the OpenStack community took over. Finally we'll expose a few best practices that Python developers can follow to get the most of this symbiotic relationship.

1. HOW OPENSTACK
MAKES PYTHON
BETTER
(and vice-versa)

2. Hello!
I AM DOUG HELLMANN
Red Hat
Technical Committee member
PSF Fellow
@doughellmann on Twitter
dhellmann on Freenode

3. Hello!
I AM THIERRY CARREZ
OpenStack Foundation staff
Technical Committee chair
PSF Fellow
@tcarrez on Twitter
ttx on Freenode

4. 1.
OPENSTACK
A community-led project

5. Elected
team leadership
Project teams select
their own leaders every
release cycle.
INDEPENDENT GOVERNANCE
Elected
oversight board
Overall project
leadership elected by
the contributors every
year.

6. OUR BASE PRINCIPLES:
THE FOUR OPENS
Open
source
Open
development
Open
design
Open
community

7. THE BIG TENT
OpenStack is made of people

8. 2.
WHAT PYTHON BRINGS
TO OPENSTACK
Ease of Use & Inclusive Community

9. WHY OPENSTACK CHOSE PYTHON
○ Distro integration
○ Easy to read
○ Easy to learn
○ Easy to patch
○ Ops familiarity

10. WHY OPENSTACK KEPT PYTHON
○ Integration language
○ PyPI ecosystem
○ Easy to read
○ Easy to learn
○ Inclusive community

11. 3.
WHAT OPENSTACK
BRINGS TO PYTHON
Funding, Contributors, & Quality

12. EXPERIENCE SOUGHT
○ Cloud / sysadmin / devops
○ Technologies like storage or networking
○ Python

13. OPENSTACK & PYTHON JOBS
trends for jobs containing python, openstack, openstack python, storage, network, and
virtualization from indeed.com

14. SUPPLY & DEMAND
trends of salary index for python and openstack jobs from indeed.com

15. EMPLOYER INDEPENDENCE
○ Community Member
○ Reputation-based Influence
○ Job Mobility

16. INFLUX OF PYTHON DEVELOPERS
○ Converted from “Enterprise” languages
○ Growing excited about Open Source
○ Joining the Python Community

17. QUALITY
Detecting regressions before anyone else

18. 23 000

19. 23 000
Number of test runs in OpenStack
on a typical work day

20. PYMEMCACHE 1.3.0
○ Released (Friday) July 24, 2015
○ Moved exceptions around in backward-
incompatible ways
○ Bug spotted and reported July 26, 2015
○ Pymemcache 1.3.2 released July 26, 2015

21. KAZOO 2.1
○ Released May 11, 2015
○ Deadlock when acquiring a lock that is
already acquired
○ Bug reported May 12, 2015

22. NETADDR 0.7.16
○ Released August 30, 2015
○ Failing on validating a previously valid
MAC address
○ Bug reported August 31, 2015
○ Netaddr 0.7.17 released August 31, 2015

23. CONTRIBUTIONS
Direct and indirect

24. LIBRARIES WE MADE
cliff
CLI framework
stevedore
plugin patterns
pbr
packaging automation
debtcollector
deprecation manager
futurist
additions to futures
automaton
state machine library

25. TOOLS WE MADE
jjb
Jenkins Job Builder
zuul
CI gate management
reno
release notes in git
bandit
security linter
gabbi
declarative HTTP tests
gertty
console-based gerrit UI

26. UPSTREAM CONTRIBUTIONS
Packaging
packaging, pip,
setuptools, wheel
Web
Pecan, requests,
WebOb, Werkzeug
Testing
fixtures, testtools,
testrepository, tox
Database
Alembic, python-
memcache, Pandas,
redis-py, SQLAlchemy
Interpreters
CPython, PyPy, Jython
Other
Dogpile, eventlet,
iso8601, Mako,
pykerberos, retrying,
six

27. ADOPTED LIBRARIES
○ pylockfile
○ mox3
○ WSME
○ sqlachemy-migrate

28. 4.
CONCLUSION
How do we improve the
symbiosis?

29. ADOPT GATING
Taste before you commit

30. FOLLOW
SEMVER
Major.Minor.Patch

31. ONCE IT’S OUT,
IT’S OUT
Remember
eventlet 0.18.1

32. DON’T RELEASE
ON A FRIDAY
You might interfere with
someone’s idea of a
good week-end

33. CONTRIBUTE
UPSTREAM
More fixes, more
features.

34. DECOMPOSE /
REFACTOR
Make more reusable
components.

35. HIGHLIGHT
OUR WORK
Write more
documentation for the
tools we’ve already built.

36. SHARE OUR
EXPERIENCE
Talk about the patterns
we’ve adopted, and our
experience solving
complex problems.

37. Other OpenStack Community
Members at EuroPython 2016
○ Victoria Martinez De La Cruz - Build your
first OpenStack application with OpenStack
PythonSDK
○ Victor Stinner - FAT Python: a new static
optimizer for Python 3.6
○ David Flanders - OpenStack Cloud Native
Deployment for Application Developers

38. THANKS!
Any questions?
You can find us at:
@doughellmann doug@doughellmann.com
@tcarrez thierry@openstack.org
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