Skip to content
No description, website, or topics provided.
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
migrations
notes prettying up a few pages and adding a sign out button Mar 1, 2015
sirius Emulator: Decode binary payload of a device command. Mar 13, 2015
tests
.buildpacks add phantomjs for heroku Sep 27, 2014
.env
.gitignore
Procfile
README.md Poetica commit: copy change and testing poetica editing Mar 12, 2015
emulation.md Add a printer emulator. Mar 13, 2015
manage.py Add a printer emulator. Mar 13, 2015
requirements.txt

README.md

Using Sirius

First point your bridge at your laptop, port 5002 (or similar).

Then run:

$ bin/gunicorn -k flask_sockets.worker manage:app -b 0.0.0.0:5002 -w 1

Navigate browser to http://127.0.0.1:5002/

Environment variables

The server can be configured with the following variables:

TWITTER_CONSUMER_KEY=...
TWITTER_CONSUMER_SECRET=...
FLASK_CONFIG=...

For dokku this means using e.g.:

dokku config:set sirius FLASK_CONFIG=heroku
dokku config:set sirius TWITTER_CONSUMER_KEY=DdrpQ1uqKuQouwbCsC6OMA4oF
dokku config:set sirius TWITTER_CONSUMER_SECRET=S8XGuhptJ8QIJVmSuIk7k8wv3ULUfMiCh9x1b19PmKSsBh1VDM

Creating fake printers and friends

Resetting the actual hardware all the time gets a bit tiresome so there's a fake command that creates unclaimed fake little printers:

$ ./manage.py fake printer
[...]
Created printer
     address: 602d48d344b746f5
       DB id: 8
      secret: 66a596840f
  claim code: 5oop-e9dp-hh7v-fjqo

Functionally there is no difference between resetting and creating a new printer so we don't distinguish between the two.

To create a fake friend from twitter who signed up do this:

$ ./manage.py fake user stephenfry

You can also claim a printer in somebody else's name:

$ ./manage.py fake claim b7235a2b432585eb quentinsf 342f-eyh0-korc-msej testprinter

Sirius Architecture

Layers

The design is somewhat stratified: each layer only talks to the one below and above. The ugliest bits are how database and protocol loop interact.

UI / database
----------------------------
protocol_loop / send_message
----------------------------
encoders / decoders
----------------------------
websockets
----------------------------

Information flow (websockets)

The entry point for the bridge is in sirius.web.webapp. Each new websocket connection spawns a gevent thread (specified by running the flask_sockets gunicorn worker) which runs sirius.protocol.protocol_loop.accept immediately. accept registers the websocket/bridge_address mapping in a global dictionary; it then loops forever, decoding messages as they come in.

Claim codes

Devices are associated with an account when a user enters a "claim code". This claim code contains a "hardware-xor" which is derived via a lossy 3-byte hash from the device address. The XOR-code for a device is always the same even though the address changes!

The claim codes are meant to be used "timely", i.e. within a short window of the printer reset. If there are multiple, conflicting claim codes we always pick the most recently created code.

We are also deriving this hardware xor when a device calls home with an "encryption_key_required". In that case we connect the device to the claim code via the hardware-xor and send back the correct encryption key.

You can’t perform that action at this time.