Like many of you, I've had my jaw on the floor since the release of Google App Engine. Although there are skeptics out there, a careful read of their terms will show you that it's for real — Google has released GOOGLE to the world and it's not for scary marketing purposes. In fact, I've been growing tired of paranoid Google haters; I'm hoping this will shut them up for a while.
Why is App Engine such a breakthrough? The concept of a hosted web application is nothing new but it has never been done this well. Mundane server maintenance? Gone. Infinite scalability? Check. 100% uptime? Let's face it, if Google went offline you'd probably be down in a nuclear bunker playing Parcheesi.
So ... how should we leverage this tool for the greater good of the community? I can't count the ways without getting dizzy. How about let's start with a mirror of PyPi, the Python Package Index?
PyPi on the App Engine
I barely spent two days on it, but here it is: http://pypi.appspot.com/. Test it out, play with it, try to break it.
As Python grows, especially due to App Engine, PyPi needs to scale too. Zope has put together a PyPi mirror but that's the only other one I know of (actually, I can't even find the link to it right now). Coincidentally, PyPi even went offline for a few min while I was writing this blog post.
- urlfetch can't get big packages
- fetching SQLAlchemy triggered the ResponseTooLarge error but its package was barely over 1MB. We might be able to create a download proxy to work around this.
- May not be fully compatible with easy_install yet
- Can't run scripts on App Engine
- Not too big a deal, you have to think of web pages as scripts and use a separate crontab to make timed requests. There are security issues with this, but for mirroring pypi it's not a problem
- Note that I haven't actually mirrored all of PyPi, I'm still testing it out.
- It's not very pretty yet (see below)
- The prototype works, now it needs some tests :)
You Can Help
I'm not dedicated to this project, I just thought it sounded like a good idea and would be a fun way to experiment with the App Engine. If anyone is interested in working on it just let me know --email@example.com. If there is enough interest I'll put it on Google Code. Possibly the most exciting feature of App Engine is the Datastore API (aka BigTable) and Ben Bangert agrees. It's a little hard for me to wrap my head around it but so far the Expando class—besides being the coolest name for a class—seems to work great for storing package data. If EGG-INO grows a new parameter, it just gets tacked on to the row dynamically.
This has also been a great way to dig up bugs, some of which have already been fixed.