tools/android/loading Add appengine frontend for Clovis

tools/android/loading/frontend/README.md

+# Appengine Frontend for Clovis
+
+[TOC]
+
+## Usage
+
+Visit the application URL in your browser, and upload a JSON dictionary with the
+following keys:
+
+-   `action` (string): the action to perform. Only `trace` is supported.
+-   `params` (dictionary): the parameters associated to the action. See below
+    for more details.
+-   `taskqueue_tag` (string, optional): the [TaskQueue][2] tag internally used
+    to send the work from AppEngine to ComputeEngine.  If this parameter is not
+    specified, a unique tag will be created.
+
+### Parameters for the `trace` action.
+
+-   `urls` (list of strings): the list of URLs to process.
+-   `repeat_count` (integer, optional): the number of traces to be generated
+    for each URL. Defaults to 1.
+-   `emulate_device` (string, optional): the device to emulate (e.g. `Nexus 4`).
+-   `emulate_network` (string, optional): the network to emulate.
+
+## Development
+
+### Prerequisites
+
+-   Install the gcloud [tool][1]
+
+-   Add a `queue.yaml` file defining a `clovis-queue` pull queue that can be

[blundell, 2016/04/19 11:05:25]

Where should this be added?

[droger, 2016/04/19 11:38:29]

Added some more comments.

+    accessed by the ComputeEngine service worker associated to the project.
+    Example:
+
+```
+# queue.yaml

[blundell, 2016/04/19 11:05:25]

What exactly does this do?

[droger, 2016/04/19 11:38:29]

Added some more comments.

+- name: clovis-queue
+  mode: pull
+  acl:
+    - user_email: me@address.com
+    - user_email: 123456789-compute@developer.gserviceaccount.com
+```
+
+### Run Locally
+
+```shell
+# Install dependencies in the lib/ directory.

[blundell, 2016/04/19 11:05:25]

Will this pollute the local Chromium checkout?

[droger, 2016/04/19 11:38:29]

Yes. In particular this will make `git cl upload` extremely slow, because it
will try to run the linter over all the appengine code.

Unfortunately, I don't think there is a good way around it. The only think I can
think of would be to copy the directory elsewhere before running the commands.

Adding a paragraph explaining how to cleanup the repo.

+pip install -r requirements.txt -t lib
+# Start the local server.
+dev_appserver.py .
+```
+
+Visit the application [http://localhost:8080](http://localhost:8080).
+
+### Deploy

[blundell, 2016/04/19 11:05:25]

Add a section documenting the high-level organization (app.yaml file, how
clovis_frontend.py works, etc).

[droger, 2016/04/19 11:38:29]

Done.

+
+````shell
+# Install dependencies in the lib/ directory.
+pip install -r requirements.txt -t lib
+# Deploy.
+gcloud preview app deploy app.yaml
+```
+
+[1]: https://cloud.google.com/sdk
+[2]: https://cloud.google.com/appengine/docs/python/taskqueue