From Hello World to Guestbook 

The prototype app for any development environment is Hello World, a program that starts up, displays the text Hello World and then exits. That's the first thing they show you how to do in any development environment, and it's often the hardest step because to get it running you have to get over all the things that make your computer different from the one the tutorial was written on.

Yesterday I got the Hello World app for Google's appengine running on my system. The hurdles were: 1. My text editor attaches an invisible ".txt" extension to the filenames of all files it creates and 2. Unix files have the newline character as the line delimiter not carriage return. Once these were fixed, the Hello World app ran.

Then it was a short sprint through all the features in the Google tutorial that led to a Guestbook app, which is now deployed and running on Google's "appspot" server.

http://dwtestbed.appspot.com/

You can try it out. Scroll to the bottom and enter some text. Then log in, and do it again.

They provide a very nice dashboard for me to monitor the Guestbook app. Here's a screen shot. It shows you how much of the resources allocated to my app are being used: CPU, network bandwidth, server storage, number of emails sent.

I wanted to give it a scripting.com domain, but the process for doing so is way too complex and (not sure) I think it might cost money. Amazon has this down to its bare simplicity, just point a domain at their server, and name the top-level bucket the same as the domain and it just figures it out.

Anyway, on the whole the process with Google's AppEngine was mostly painless and quite rewarding. Next steps will reveal how flexible it is, how easily I can turn my simple guestbook into something more useful.

BTW, I recall that Python has excellent XML-RPC support. I wonder if that's enabled in Google's environment?