The Multi-Snake project was created to support the talk Processes & Grains A Journey in Orleans at Code BEAM Europe 2022 on 19 May 2022.
A copy of the deck can be found here.
A deployed version on Fly.io is available at https://snake-web.fly.dev.
- Classic snake game.
- With responsive design based on SVG rendition of the game board.
- With example Dockerfile for deployment on Fly.io or other cloud providers, encapsulating full Elixir releases with fully generated and digested Phoenix assets.
- With custom Cowboy 2 integration, working for both Plug-based and WebSocket-based traffic, allowing seamless integration of multiple Phoenix Endpoints in different applications, including fully working Phoenix Sockets.
- With Phoenix LiveView integration, to provide the user interface, including event handling.
- With Phoenix Presence integration, to count live players.
- With custom esbuild integration, allowing straightforward integration of NPM modules, such as bootstrap.
- With libcluster integration, to provide intra-node clustering via Erlang Distribution.
- With erleans & horde integration, to showcase available strategies that can be used to build backends, alongside with straightforward implementation of snapshots (checkpoints) to ensure continuity of processing.
To run the code:
- Clone the repository.
- Install the appropriate Erlang, Elixir and Node.js verisons via asdf (see
.tool-versions). - Run
mix deps.get. - Run
mix ecto.setup. - Run
./bin/run. - Visit
https://localhost:4000. - For additional nodes, run
./bin/console.
The Multi-Snake application is an umbrella application with the following applications:
snake: Holds the core game logic and backends.snake_data: Holds Ecto Repo and all migrations.snake_environment: Holds clustering and endpoint configuration logic.snake_proxy: Holds a connection proxy allowing numerous Phoenix apps to be hooked.snake_web: Holds the main Web application containing a LiveView interface.
Within apps/snake/config/config.exs, the appropriate Backend can be selected:
config :snake,
backend_module: Snake.Game.Backend.HordeStatem
Where 3 distinct backends are available:
-
Snake.Game.Backend.ErleansGrain, implemented as a stateful Erleans Grain, preferring local activation. -
Snake.Game.Backend.HordeServer, implemented as a GenServer registered under a distributed supervisor offered by Horde. -
Snake.Game.Backend.HordeStatem, implemented as a GenStateMachine (Elixir wrapper of gen_statem) registered under a distributed supervisor offered by Horde.
Via Prepared Script:
$ flyctl ssh console
> /app/migrate.sh