SafetyNet

Running the code

First install dependencies and start the Mix project in iex:

mix deps.get
iex -S mix

You can now initialise a demo with:

Demo.init()

This should initialise a demo with several ships. You will see log messages in the terminal. To simulate a failure, run:

Demo.stop(:A)

Adding ships

You can add a new ship with:

Demo.add_ship(:ship_id, [:ship_2, :ship_3])

By default the new ship's coordinates will be {0,0} but you can also specify them if you like by passing them as a third argument:

Demo.add_ship(:ship_id, [:ship_2, :ship_3], {10,10})

You can also add multiple ships at once, for example:

Demo.add_ships(10, [:ship_2, :ship_3])

Connecting to the Lighthouse frontend

The Lighthouse is a Phoenix app that uses PubSub to receive broadcasts about the ships and display them.

Start the Lighthouse with a cookie and a node name, e.g.:

iex --name lighthouse@localhost --cookie secret -S mix phx.server

Now when you start the SafetyNet app, use the same cookie:

iex --name <node_name> --cookie secret -S mix

Then connect SafetyNet to the Lighthouse by running:

Node.connect(:lighthouse@localhost)

Now the nodes should be connected. You can start the demo and the ships will broadcast updates to the Lighthouse automatically.

Running multiple nodes

To create a node:

iex --sname <node_name> --cookie secret -S mix

Now at this point if you have the Lighthouse running, you can simply connect each extra node running SafetyNet to the Lighthouse. They will join the network and be able to communicate with ships on other nodes.

If you aren't running the Lighthouse, simply connect nodes to each other:

Node.connect(:"node_name@user")

To run a distributed demo, run Demo.init() in one terminal and in the other add some ships:

Demo.add_ship(:F, [:B, :C], {1, 1})
Demo.add_ship(:G, [:A])

Running tests

There are a few tests, you can run them with the following command:

mix test