# Clusterable

`Clusterable` prepares a node to be clustered.

With `Clusterable`, you can forget about special settings/configurations
for clustering. And you no longer need to start Elixir/Erlang with `--sname`
or `--name`.

If you use `Clusterable` and `Peerage` together, clustering just becomes
so easy and happens like magic!

*Not tested with `libcluster` but should work too*

## Installation

It's [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `clusterable` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [{:clusterable, "~> 0.1"}]
end
```

It's tested with [Peerage](https://github.com/mrluc/peerage), if you want to use
it with `Peerage`:

```elixir
def deps do
  [{:clusterable, "~> 0.1"},
   {:peerage, "~> 1.0"}]
end
```

It should work with [libcluster](https://github.com/bitwalker/libcluster) as well

```elixir
def deps do
  [{:clusterable, "~> 0.1"},
   {:libcluster, "~> 2.0"}]
end
```

Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
be found at [https://hexdocs.pm/clusterable](https://hexdocs.pm/clusterable).

## Example Config with Peerage

If using peerage dns, make sure the two `app_name`
configs are the same.

```elixir
config :clusterable,
  cookie: :cluster,
  app_name: "elixir"

config :peerage, # if using DNS
  via: Peerage.Via.Dns,
  dns_name: "peer",
  app_name: "elixir"

config :peerage, # if using UDP
  via: Peerage.Via.Udp,
  serves: true,
  port: 45900
```

## Example Usage

Add Clusterable to a supervision tree as a transient worker

```elixir
worker(Clusterable, [], restart: :transient)
```

If you are playing with it in IEx, you can start it manually

```elixir
Clusterable.start_link
```

## Testing with Docker 1.10+

- clone Clusterable project
- uncomment according configs in `config/config.exs`
- remove `optional: true` in `mix.exs` for `:peerage`
- in the project dir, run the commands below:

    docker build -t clusterable .
    docker network create test -d bridge

    # open shell 1
    docker run --rm -it --network test --network-alias peer clusterable
    iex> Clusterable.start_link

    # open shell 2, do the same
    docker run --rm -it --network test --network-alias peer clusterable
    iex> Clusterable.start_link