The document discusses the state of WebDAV and Davvy, an open source Python library for implementing WebDAV. It summarizes the challenges with WebDAV, including that it uses XML for requests and responses, which can become complex. It then introduces Davvy as a way to implement WebDAV in Python using Django paradigms and models to simplify development. Finally, it notes that while Davvy works, client support remains problematic and continues to evolve, posing an ongoing challenge for WebDAV implementations.

1. DAVVY
DJANGO,WEBDAV E
(PESSIMO) STATO DELL'ARTE
Adriano Di Luzio
Sabato 18 Aprile 2015 - Firenze - PYCONSEI

2. ABOUT ME
Software Developer - Unbit, Roma
Studente - Informatica Magistrale @ Sapienza
www.github.com/aldur
www.twitter.com/AdrianoDiLuzio
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3. DAVVY: IL SOGNO
3
WebDAV

4. WEBDAV:WHAT?
• Web Distributed Authoring and Versioning [1]
• Estensione di HTTP
• Il web - medium per lettura e scrittura
4
[1] rfc4918

5. WEBDAV:WHO?
Apple (OS X & iOS clients)
Google (Android Calendars, Contacts)
E molte altre implementazioni.
5

6. WEBDAV: HOW?
6
HTTP / WebDAV Request
PROPFIND (XML)
HTTP / WebDAV Response
PROPFIND (XML)
HTTP / WebDAV Request
MKCOL
…

7. HAI DETTO XML?
<D:prop
xmlns:D='DAV:'><author
xml:lang='en'
xmlns:x='http://example.com/ns'
xmlns='http://example.com/ns'
xmlns:h='http://www.w3.org/1999/xhtml'>
<x:name>Jane
Doe</x:name>
<x:uri
added="2005-­‐11-­‐26"
type="email"
>mailto:jane.doe@example.com</x:uri>
<x:uri
added="2005-­‐11-­‐27"
type="web"
>http://www.example.com</x:uri>
<x:notes>
Jane
has
been
working
way
<h:em>too</h:em>
long
on
the
long-­‐awaited
revision
of
&lt;RFC2518&gt;.
</x:notes>
</author>
</D:prop>
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8. XML & HTTP: RICHIESTA
PROPFIND
/container/
HTTP/1.1
Host:
www.example.com
Content-­‐Type:
application/xml;
charset="utf-­‐8"
Content-­‐Length:
xxxx
<?xml
version="1.0"
encoding="utf-­‐8"
?>
<propfind
xmlns="DAV:">
<propname/>
</propfind>
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9. XML & HTTP: RISPOSTA
HTTP/1.1
207
Multi-­‐Status
Content-­‐Type:
application/xml;
charset="utf-­‐8"
Content-­‐Length:
xxxx
<?xml
version="1.0"
encoding="utf-­‐8"
?>
<multistatus
xmlns="DAV:">
<response>
<href>http://www.example.com/container/</href>
<propstat>
<prop
xmlns:R="http://ns.example.com/boxschema/">
<R:author/>
<creationdate/>
<displayname/>
<resourcetype/>
</prop>
<status>HTTP/1.1
200
OK</status>
</propstat>
</response>
<!-­‐-­‐
...
-­‐-­‐>
</multistatus>
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10. Template
DJANGO & DAVVY
Architettura e paradigmi
10
Model
View

11. DJANGO & DAVVY
Architettura e paradigmi
10
Model
View

12. Storage
DJANGO & DAVVY
Architettura e paradigmi
10
Model
View

13. Storage
DJANGO & DAVVY
Architettura e paradigmi
10
Model
View
Properties
XML → WebDAV
Model → XML
Resources
Collections

14. DAVVY: DETTAGLI
• Python 2 / Python 3.
• Estendibile a piacimento (Class-View based)
• Condivisione / protezione delle risorse.
11

15. DAVVY: SET-UP
#
settings.py
DAVVY_STORAGE_PATH
=
'/var/www/davvy'
12
#
urls.py
from
davvy.base
import
WebDAV
from
davvy.addressbook
import
CardDAV
from
davvy.calendar
import
CalDAV
urlpatterns
=
patterns('',
url(r'^principals/(w+)/(.*)',
WebDAV.as_view(root='storage')),
url(r'^storage/(w+)/(.*)',
WebDAV.as_view(root='storage')),
url(r'^addressbook/(w+)/(.*)',
CardDAV.as_view(root='addressbook001')),
url(r'^calendars/(w+)/(.*)',
CalDAV.as_view(root='calendars')),
url(r'^admin/',
include(admin.site.urls)),
)

16. DAVVY: CUSTOMDAV
13
class
CustomDAV(WebDAV):
def
__init__(self,
**kwargs):
self.http_method_names
=
WebDAV.http_method_names
+
['custom']
super(CalDAV,
self).__init__(**kwargs)
def
propfind(self,
request,
user,
resource_name):
return
super(CalDAV,
self).propfind(
request,
user,
resource_name,
shared=True)
def
put(self,
request,
user,
resource_name):
return
super(CalDAV,
self).put(request,
user,
resource_name)
#
[…]
def
custom(self,
request,
user,
resource_name):
#
A
custom
HTTP/WebDAV
method!
pass

17. LO STATO DELL’ARTE
L’INCUBO: I CLIENT
14
OS X Calendar MozillaThunderbird

18. OS X CALENDAR
• Homesets Autodiscovery
• Richieste volanti (PROPFIND /)
• .well-known/{caldav, carddav}
15

19. MOZILLATHUNDERBIRD
1. Nessun supporto out-of-the-box.
2. Lightning Calendar Extension.
3. Nessun supporto i’ll-build-the-box.
16

20. I CLIENT: ROUND II
17
OS X Contacts
MozillaThunderbird
+
SOGo

21. I CLIENT: ROUND III
18
OS X Finder Transmit

22. SENZA FINE!
19

23. E NON SIAMO GLI UNICI!
sabre/dav
20
owncloudradicale
milton

24. L’ALTERNATIVA
https://github.com/unbit/spockfs
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25. CONCLUSIONI
• Abbiamo imparato molto…
• …soprattutto a stare lontani da WebDAV!
• Nonostante questo, Davvy funziona!
• Almeno fino al prossimo giro di client.
22

26. GRAZIE PER L’ATTENZIONE.
DOMANDE?
23
https://github.com/unbit/davvy/

27. CREDITI RISORSE GRAFICHE
• http://www.kameleon.pics/
• http://icons8.com/
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