Dojo 1.2 and Django 1.0 on Google App Engine 1.1.3

September 17, 2008

Important Update: Use Google App Engine Patch for Django integration instead. It integrates Django seamlessly and includes lots of other goodies. For Dojo, also consider using xdomain and loading Dojo from Google’s AJAX Libraries API. For Google App Engine Patch, see my more recent post. This area changes quickly, so check the dates on any blog posts you’re looking at!

With the release of Google App Engine 1.1.3 (GAE), it’s now much more realistic to serve up Dojo on GAE. LittleShoot uses a lot of Dojo (mostly because it rocks), so getting Dojo up and running on our new GAE LittleShoot port has been a high priority.  

The problem is that vanilla Dojo quickly runs up against GAE’s 1000 file limit per application. Django has the same problem. Our initial solution was to run a custom build that would delete a lot of unnecessary files, with thanks to Peter Higgins from SitePen for lighting our path. This got our build down to about 700 files, solving the problem for the basic LittleShoot site.

We’re getting ready to release the LittleShoot platform, however, that allows any site to detect if LittleShoot’s installed and to call the LittleShoot “P2P 2.0” API if it’s available. That means we need external sites to be able to load our JavaScript, i.e. we need to support Dojo’s cross-domain builds. The cross-domain build adds about another 500 files, pushing us again over the 1000 file limit.

Thankfully, GAE 1.1.3 introduces “zipserve,” allowing you to serve static files directly from a zip file. Guido van Rossum deployed a similar technique for serving Django for his fantastic Rietveld code review tool and GAE demo app, but that only works for loading python code. So we copied Guido for loading Django 1.0, and now zipserve allows us to do more or less the same thing for Dojo.  

To serve Dojo using zipserve, you basically modify your app.yaml to include something like the following:

– url: /dojo/.*
  script: $PYTHON_LIB/google/appengine/ext/zipserve

– url: /dijit/.*
  script: $PYTHON_LIB/google/appengine/ext/zipserve

– url: /dojox/.*
  script: $PYTHON_LIB/google/appengine/ext/zipserve

 

This will look for dojo.zip, dijit.zip, and dojox.zip files in your *top-level* directory, the same directory containing app.yaml. You need to separate the zip files to avoid running up against the GAE limit on file sizes (1MB I believe). The zip file name basically acts like a directory in App Engine’s URL resolution. So, when a request goes to http://beta.littleshoot.org/dojo/dojo.js, for example, it loads dojo.js from dojo.zip (not from the dojo directory within dojo.zip). Here’s our script for generating the zips:

#!/usr/bin/env bash

function die()
{
  echo $*
  exit 1
}

cd static/js
dirs=”dojo dijit dojox littleshoot”

for x in $dirs
do
  cd $x || die “Could not cd to $x”
  echo “Building zip for $x”
  zf=../../../$x.zip
  rm $zf
  zip -rv $zf * || die “Could not create zip”
  cd ..
  # We actually delete all the contents because we don’t want to 
  # include them in GAE.
  rm -rf $x
done

exit 0

Even with separating the zip files, dijit and dojox will still come close to the 1MB limit on file sizes.  We use rsync excludes to get rid of the files we don’t need.  Here’s our bash rsync excludes function, which you can customize to your liking (careful not to exclude anything you need!!):

function excludeRsync
{
  rsync –exclude .svn/ \
        –exclude test/ \
        –exclude tests/ \
        –exclude demo/ \
        –exclude demos/ \
        –exclude soria/ \
        –exclude nihilo/ \
        –exclude grid/ \
        –exclude charting/ \
        –exclude util/ \
        –exclude analytics/ \
        –exclude collections/ \
        –exclude README* \
        –exclude *.psd \
        –exclude *.uncompressed.js \
        –exclude *.commented.css \
        –exclude dijit/templates \
        –exclude dijit/form/templates \
        –exclude dijit/layout/templates \
        –exclude *silverlight* \
        –exclude gfx3d/ \
        –exclude dojo/_base/ \
        –exclude dojo/_base.js \
        –exclude dojo/build.txt \
        –exclude functional/ \
        –exclude off/ \
        –exclude presentation/ \
        –exclude sketch/ \
        –exclude storage/ \
        –exclude wire/ \
        –exclude data/ \
        –exclude dtl/ \

        -avz $tmpDir/js $releaseDir || die “Could not sync”

}

We call the rsync script after running our dojo build.  The dojo build puts everything in the “$tmpDir/js” directory listed on the last line of the rsync.

OK, so there are still some hoops to jump through, but it works!  On the Django 1.0 side, I’d highly recommend copying Guido’s Rietveld settings.  The Google App Engine Django Helper is also useful, but Django 1.0 support hasn’t been released as of this writing.  We’re using Guido’s settings for now — basically the Makefile, make_release.sh, settings.py, and main.py.  Oh, I also tweaked his rietveld.py script, turning it into littleshoot.py.  You can find all of these files in the Rietveld svn here.  Most of the tweaks to these files are pretty obvious when you glance at the scripts — nothing super complicated going on.  Not that it’s a breeze, but each files is individually fairly straightforward.  The scripts will also create a zipped version of django from the django directory, so using svn:externals (described below) is handy.

We load both Django and Dojo with svn:externals. You might be on information overload at this point, but here’s another little nugget if you’re still with me. You can run the following in the respective directories where you want Django and Dojo to reside.

svn –editor-cmd=vim pe svn:externals .

For Dojo, enter the following:

dojo http://svn.dojotoolkit.org/src/tags/release-1.2.0b2/

For Django, try:

django http://code.djangoproject.com/svn/django/trunk/django

That will put Dojo 1.2 beta 2 in the “dojo” directory and the Django trunk in the “django” directory when you run “svn up”.  

If you successfully navigate through all of that, the end result is the latest Dojo and the latest Django running on the spanking new Google App Engine 1.1.3. Web app setups just don’t get any sweeter. If you’re a total geek like me, that’s living the good life! Sad, I know…

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TechCrunch 50, LittleShoot, and the Aftermath

August 15, 2008

Things have been on hold here for the public release of LittleShoot as we have awaited word on our TechCrunch 50 application.  We didn’t make it! Darn.  It came down to the wire — we were in the last batch of companies to receive notification we weren’t in the conference on Friday at 1:24 AM EST. The 50 companies that made it in should know now.  Here’s the e-mail:

 

Dear TechCrunch50 Candidate:

We are sorry to inform you that your company was not selected as a finalist for the TechCrunch50 conference. As you know, we are only able to select a very, very small percentage of the more than 1,000 outstanding applications we receive.

Your company was among a select set of candidates that we considered, and it was a difficult decision driven purely by the limited number of presentation slots. Since we regarded your business so highly, we want to make sure you still get the opportunity to participate in the conference in our DemoPit.
(http://techcrunch50demopit.eventbrite.com).

As a DemoPit company, you will have the opportunity to be nominated for the People’s Choice award and win the 50th spot on the TechCrunch50 main stage. As the 50th company to present, the People’s Choice award winner will be able to compete for the $50,000 TechCrunch50 award. Act fast, as spaces are very limited and first come, first served.

Additionally, all DemoPit companies will benefit from the exposure generated by media attending the event. We do anticipate having approximately 300 members of the international press in attendance.

If you have questions regarding the TechCrunch50 Demo Pit opportunity, please email Dan Kimerling at dan@techcrunch.com.

Sincerely,

–Jason, Heather & Michael
and the TechCrunch50 Team

 

I’ve got a lot of respect for the TechCrunch folks and the way they give unfunded companies a shot, and I thoroughly enjoyed meeting Jason Calacanis down at the Mahalo Tech Meetup last night in one of my first nights in LA. I appreciate the tremendous work Jason, Michael, Heather, and the other folks at TechCrunch have put it to the process.  

That said, it’s on.  I feel like the guy on draft day who didn’t go on the first round.  It’s the “meritocracy” thing that gets me – TechCrunch 50 is touted as a pure meritocracy.  I’d put LittleShoot’s technology up there with anyone, and it just kills me to think 50 startups beat us out.  We can tell ourselves they had better business models, better marketing plans, yada yada yada, but I’m taking it to mean they had better technology.  If there’s anything that motivates me, that’s it. I have great respect for the other applicants, and we all supported each other on the TechCrunch blog as we agonized through the waiting process.  I wish everyone the best of luck, but the LittleShoot public beta is on its way.

Here’s a link to the LittleShoot demo video we submitted for TechCrunch for people unfamiliar with the Little Fella’:

LittleShoot Demo