Slides from RuPy 2009 talk "Compiled Websites with Plone, Django, Xapian and SSI" by Łukasz Langa and Wojciech Lichota.

1. Compiled Websites
with Plone, Django and SSI
Łukasz Langa" "
Wojciech Lichota"

2. Agenda
 Reasoning
 Plone and Static Deployment
 Django and SSI
 Search (Xapian)

3.  Security
solutions requiring 100%
guarantee that the
content cannot be edited
from the Web
Reasoning  Performance
The Problem dynamic Websites are
resource hungry
 Quality Assurance
the ability to review
complete content and
functionality before every
deployment

4.  Security
front-end/back-end
division
two-level authentication
Reasoning  Performance
throwing hardware at the
Existing Approaches problem
caching
 Quality Assurance
dedicated workflow
environments
test instances

5. Reasoning
The Solution
Website compilation

6.  Convert all Website
resources to static files
 HTML
 CSS
 JS
The Solution  attachments
Static Deployment  media
 Deploy the HTML on
a traditional Web server
✓ orders of magnitude
better performance
✓ incredibly simple
scalability
✓ server-agnostic quality
assurance

7.  Examples:
 HTTrack
 wget
-­‐-­‐mirror
Static
Deployment ✓ out-of-the-box solution
with external tools ✗ weak control of output
✗ slow

8.  Solutions for Plone:
 enpraxis.staticsite
 stxnext.staticdeployment
Static ✓ much faster than external
Deployment solutions
with internal tools ✓ fully configurable
✓ easy to customize
✗ needs integration with
website

9.  Open-Source (ZPL)
 two parts of configuration
Static  basic: for content editors
 advanced: for
Deployment administrators
stxnext.staticdeployment
 incremental
 content transformations
 pluggable
 integration with Xapian

10. stxnext.staticdeployment

11. stxnext.staticdeployment

12.  User profiles
 Commenting
Static  User communication
Deployment  Search
...too static!
We need something more
sophisticated!

13.  Plone + Static
Deployment
The Solution  Django for:
 User profiles
 Commenting
 User communication
 Xapian for search
Compiled Website

14. How to glue components
together?
The Solution
 client-side approach:
JavaScript
✓ simple implementation
✗ many requests
✗ page flickering
 server-side approach:
Apache SSI
✓ single request
✓ transparent to the user
Compiled Website ✗ skin customization

15.  HTML preprocessor
provided by Apache httpd
at least since version 1.3
 Processing controlled by
The Glue SGML comments
 Basically enables:
Apache mod_include (SSI)
 conditional text
 inclusion of other files
 inclusion of programs
 printing/setting
environment variables

16.  A basic SSI element:
Apache mod_include
<!-­‐-­‐#element
attribute=value
attribute=value
...
-­‐-­‐>
no whitespace
 Typical elements:
 #include
 #echo
 #exec
 #set
 #if
/
#elif
/
#else
/
#endif

17.  Enabling SSI in the server configuration:
Apache mod_include
...
LoadModule
include_module
modules/mod_include.so
...
AddType
text/html
.html
AddOutputFilter
INCLUDES
.html
...
Options
+Includes
 Examples of basic directives:
 current date on the server
<!-­‐-­‐#echo
var="DATE_LOCAL"
-­‐-­‐>
 file modification date
Last
modified:
<!-­‐-­‐#flastmod
file="index.html"
-­‐-­‐>
 inclusion of results from a dynamic application
<!-­‐-­‐#include
virtual="/app-­‐comments/thread/3/"
-­‐-­‐>
 executing local commands
<!-­‐-­‐#exec
cmd="uptime"
-­‐-­‐>

18.  Inclusion of results from a dynamic application
<!-­‐-­‐#include
virtual="/app-­‐comments/thread/3/"
-­‐-­‐>
Apache mod_include
 How to specify an external application to be available
from /app-­‐comments
?
RewriteEngine
on
RewriteRule
^/app-­‐comments/(.*)$
http://localhost:8686/$1
[L,P]
 What if the external application is not available?
 Apache includes the following message by default:
[an
error
occurred
while
processing
this
directive]
 This can be customized in server configuration by:
SSIErrorMsg
"<!-­‐-­‐
Error
-­‐-­‐>”
 The default message can be overriden in HTML by:
<!-­‐-­‐#config
errmsg=”Custom
message"
-­‐-­‐>

19.  context-specific arguments
need to be GET params
 by default Django uses
URL parts
Gotchas  redirect after POST
requests
Gluing Django with SSI  POST requests cannot
render anything
 form validation requires
additional plumbing
 Website templating in two
places
 Plone skin
 Django templates

20.  Apache is slow...
Gotchas
Apache httpd

21.  Apache is slow... NOT!
 mpm_prefork
is evil
 use mpm_worker
 any experience with
mpm_event?
Gotchas  Advantages of Apache:
Apache httpd  largest install base
 maturity measured in
years
 the best WSGI module
available (mod_wsgi)

22. 
python-­‐xapian
binding
 Ranked search
What about  Suggests spelling
corrections
search?  no Polish stemming
Xapian with SSI

23. Compiled Websites
Starring
Łukasz Langa"
lukasz.langa.pl
lukasz@langa.pl
@llanga
"

24. Compiled Websites
Starring
Wojciech Lichota
www.lichota.pl
wojciech@lichota.pl
@wlichota
"

25. Compiled Websites
Guest Starring
Django Pony
www.djangopony.com
@djangopony
"

26. Questions?