Hello, Merbists!

Today, I explain how to develop Merb apps that runs on GAE/J environment by using dm-datastore-adapter.

First of all, here is whole source code of an example app. Please check it out.

• http://github.com/genki/hello-gae/tree/master

After checking it out, you must edit appengine-web.xml file. Open it by editor and change the application name to yours. And then you should make war directory by typing this command.

   1  MERB_ROOT% jruby -S warble war

It generates files under tmp/war.

So far, you are ready to deploy this app to GAE/J Of course, you need an account of GAE/J to do it. Please get it in advance :-)

Let us go to deploy by this command.

   1  MERB_ROOT% appcfg.sh update -e {youraccount@gmail.com} tmp/war  

This process takes a time for the first time. If the log didn't say any errors, you got success!

Now your first Merb app on GAE/J is here at http://{your app name}.appspot.com/

Congrats!

Further improvement is your home work :-p

APPENDIX

All required gems are being packed into jar file located at lib/merb.jar. This enables you to pass the limit of which you can upload only 1000 files to GAE. If you add more gems to the jar file, you can do it like this

• unpacking it
• add gems
• and repack it

Enjoy!