Lecture 5

Resources

• Code of Android App
• Direct view of backend code we developed for the class
• web2py documentation
  • Google Appengine documentation (this is what we use to serve the backend)
  • NDB introduction and documentation (this is the database we use)

How to build and deploy a cloud backend

First, build the app

The official steps are as follows, but see below for a shortcut. The steps may contain errors; it's difficult to remember exactly this long sequence of steps.

• Download the source version of web2py
  • Unzip it
  • cd web2py
  • cp -r applications/welcome applications/backend
  • mv examples/app.example.yaml app.yaml
  • Edit app.yaml, removing the version and the application/project information.
  • cp examples/routes.parametric.example.py routes.py
  • Edit routes.py to define 'backend' as the default application.
  • Your code now goes into applications/backend/controllers/api.py (create this file, it does not already exist).

Or use this shortcut: download the web2py zip file at the bottom of this page, and just edit applications/backend/controllers/api.py

Then, upload the app

• Install the Google Cloud SDK
  • Configure it, for instance:

gcloud config set account luca@ucsc.edu ;; (for example)

gcloud config set project luca-ucsc-teaching-backend ;; (for example)

gcloud auth login

gcloud config set app/promote_by_default false

gcloud components update

• Go to the Google Cloud Console.
• Create a new project. You can choose any name you like, but once you create the project, you can't change the name any more.
• When you create a new project, you will need to create a billing account. You won't be billed unless you use more than your free quota.
  • Upload your application. You can use a command line similar to the following one, where the "--promote" flag is used to ensure that the version you have uploaded starts receiving all the traffic:

gcloud app deploy --promote web2py_backend_spring2017/app.yaml

• Your app is then accessible from a URL like https://yourproject.appspot.com/api/your_function

Video

Unfortunately, the video file was corrupted, and I was not able to salvage it.