Deployment issues surrounding the use of virtualenv within Debian packages at Spotify

1. 1
Spotify Tech
Web/iOS/Android/Native clients
Service oriented architecture > 50 services in Java and Python
Primarily using Cassandra for persistent storage
7,000 Servers in production
~500 in Engineers worldwide

2. 2
What have we been
doing?
Lost in the forest of dependency building

3. 3
Deploy via Debian Packages
Use Debian Stable repositories
Package/Backport needed libraries as needed
All Dependencies defined in Debian package
Deployed via Puppet/Aptitude

4. 4
Mirroring
P
a
c
k
a
g
e
A
p
p
s
P
y
P
i

5. 5
What’s wrong with
that?
Spending too much time managing
dependencies and not enough building cool
shit

6. 6
Using Debian Stable does not included latest and
greatest

7. 7
Requires “Backporting” for newer libraries

8. 8
Does not used normal python packaging

9. 9
Limited use on developer systems
(or bad/duplicated information)

10. 10
Full rollback non-existent

11. 11
What you test is NOT what you deploy

12. 12
Dependency lock in due to sharing a common python
environment

13. 13
There MUST be a better way
Avoid duplication of effort

14. 14
There MUST be a better way
Increase stability and repeatability

15. 15
There MUST be a better way
Offer easy rollback

16. 16
There MUST be a better way
Scale

17. 17
What about now?
Deploying Python @ Scale

18. 18
Enter Dh-viurtualenv

19. 19
Dh == Debian Helper
•
•
•
•
•
Registers itself as a Debian Helper
Bundles the requirements in requirements.txt into virtual environment
Deploys virtualenv into /usr/share/python/<package-name>
Still requires native dependencies to be installed via packaging
Just include the following in the debian/rules:
%:
dh
$@
-­‐-­‐with
python-­‐virtualenv

20. 20
Mirroring
V
i
r
t
u
a
l
e
n
v
Pip
A
p
p
s

21. 21
IT Works!

22. 22
Example: Using Sentry
Define Dependencies in requirements.txt
sentry[postgres]==6.2.0
eventlet==0.13.0
hiredis==0.1.1
django-­‐auth-­‐ldap==1.1.4

23. 23
Example: Using Sentry
Define Debian dependencies in control file
Build-Depends:
python (>= 2.6.6-3~),
debhelper (>= 8),
dh-virtualenv,
python-dev,
libpq-dev,
libldap2-dev,
libsasl2-dev,
Standards-Version: 3.9.3
X-Python-Version: >= 2.6

24. 24
Example: Using Sentry
Use dh_virtualenv in Debian rules file
%:
dh $@ --with python-virtualenv
override_dh_virtualenv:
dh_virtualenv --index-url='http://localhost/simple'

25. 25
Have done this with RPMs as well (@ Amplify)
Within RPM build virtaulenv and mark it as
relocatable:
/usr/local/bin/virtualenv --no-site-packages build_venv
source build_venv/bin/activate
env CFLAGS="$RPM_OPT_FLAGS" easy_install -Z .
deactivate
/usr/local/bin/virtualenv --relocatable build_venv

26. 26
Benefits
No longer stuck on Debian stable

27. 27
Benefits
No more backporting of new libraries or versions

28. 28
Benefits
Code isolation/use own dependencies

29. 29
Benefits
Single package rollback option

30. 30
Benefits
Development and Deployed systems using same
cross-platform setup

31. 31
What’s Next?

32. 32
Not Sure…

33. 33
Dh_virtualenv now available (ironically) in Debian
Unstable repositories

34. 34
Still requires managing native dependencies locally

35. 35
But experimenting with containers!

36. 36
Stay Tuned!

37. 37
Thanks to Jyrki
Pulliainen and Jim
Whitehead @ Spotify
Stockholm!
Whitepaper:
http://labs.spotify.com/2013/10/10/packagingin-your-packaging-dh-virtualenv/
Code: https://github.com/spotify/dh-virtualenv

38. 38
Questions?
Chris Angove, Chapter Lead - Backend
Email: cangove@spotify.com
Blog: http://labs.spotify.com/
Listen: https://play.spotify.com/

39. Want to join the band?
Check out spotify.com/jobs or
@Spotifyjobs for more information.
January 24, 2014