This project was done in a group of 5 people who were responsible for differenet tasks.

Repository structure
--------------------

./
  android/   - android app sources. Follows standard android app structure
  external/  - extenal open source libraries (structure inspired by AOSP)
  server/    - web app and backend sources. Follows standard Express structure
  vmscripts/ - scripts used in VM instances


Server structure
------------------------

server/bin/www
    * Creates and starts the web server

server/models/user.js
    * Contains the mongoose schema and model definition.

server/passportSetup
    * Contains files for passport middleware implementation which are used for authentication.

server/views
    * Contains html files to be rendered to web client.

server/public
    * Has three subfolders:
      1. Javascript files for web frontend to be placed in 'javascripts'
      2. Style sheets for web frontend go to 'stylesheets'
      3. Images for web front-end to be saved at 'images'

server/routes/index.js
    * Handles API calls to the backend and interact with google cloud instances.

server/routes/websockify-handler.js
    * Handles noVNC/Websockify proxying.

server/db.js
    * Used to connect backend to the mogodb server.

server/app.js
    * Creates various variables and ties them to used packages, node functionality,
      and routes and implement error handling.


Android client structure
------------------------

Login Screen Activity:
    * Login screen activity shows user a login prompt after a secure log in, it
     launches Application List activity.

Application List Activity:
    * Application list launches and manages both VMs (via backend api) and Thin
      Client windows. On a new VM launch, a new Thin Clien Activity window is
      created (note: there can be multiple windows open to separate VMs) with
      proper VNC credentials (host-port-pass) tuple.

Thin Client Activity:
    * Thin Client activity starts and manages a single RFB connection via
      librfb[binding].

librfb[binding]:
    * librfb[binding] is a wrapper that provides a consistent, easy to use, api
      over a modified libvnc. It provides a clear JNI API, and a helper RFB
      connection class that simplifies its use.
    * librfb resides in external/libvncserver-LibVNCServer-0.9.10/librfbbinding
    * modified libvnc resides in external/libvncserver-LibVNCServer-0.9.10


Installing server
-------------------------

Prerequisites:
    * Google Service account key
        - https://developers.google.com/identity/protocols/application-default-credentials
    * Inbound traffic to TCP ports 3000 and 6080 are allowed in firewall

Install:
    1. Save your Google Service account key as credentials.json in the root folder of the project

    2. invoke following command in the root folder of the project
       $ ./deploy.sh

       The command uses the present working directory as the installation path. The full paths for
       credentials.json, server and external folders are derived by the commmand from the path where
       it was executed.

    3. Navigate to http://<host>:3000/


Installing android client
-------------------------

Prerequisites:
    * Recent JDK in JAVA_HOME or in path
    * Recent Android SDK in ANDROID_HOME, with license agreements accepted:
        - SDK build tools 24.0.2
        - SDK Platform 24
        - Android Support Repository
        - Google Repository
    * Recent Android NDK in ANDROID_NDK_HOME

Build and install:
    invoke following command in the root folder of the project:
    $ (cd ./android; ./gradlew installDebug -PBACKEND_URI="<host>" -PBACKEND_PORT=<port> )

    Example
    $ (cd ./android; ./gradlew installDebug -PBACKEND_URI="10.1.2.3" -PBACKEND_PORT=1234 )

    The command will install the app to the attached device. The installed app
    is a DEBUG version for convenience reasons.