I recently spent some time trying to abstract away some of the incidental complexity of using Google App Engine with Clojure. Right now, setting up interactive development and understanding what to do requires reading several blog posts, and pasting in a lot of boilerplate code. I ended up making a small library, called appengine- magic, which cuts the boilerplate down to (1) a single additional .jar dependency, (2) a couple of macros, and (3) a couple of files generated by a Leiningen plugin. It takes a Ring handler, and turns it into an application suitable for App Engine.
http://github.com/gcv/appengine-magic It doesn't do everything yet, but I feel that it already makes a much easier starting point than any alternative. The README file explains the details. Unfortunately, I hit a major stumbling block. Live deployment to App Engine does not work because of a dependency importing a blacklisted class. appengine-magic expects to deploy a Ring handler. This makes it possible to write apps using any Ring-compliant Clojure web framework. In order to deploy to App Engine, it needs to turn the handler into a servlet. The ring-servlet library does this with its handy ring.util.servlet/defservice function. The implementation of defservice uses duck-streams/copy. duck-streams imports java.net.Socket, a class blacklisted by App Engine, causing deployment to fail. So any innocuous dependency, which transitively depends on anything which loads a file which imports a blacklisted class, can cause deployment to fail. Even Clojure itself is not entirely safe: for example, duck-streams is now clojure.java.io, which imports java.net.Socket. I can reimplement defservice, and so avoid depending on ring-servlet. Still, the situation seems fragile and precarious. Suggestions and comments welcome. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
