Elixir example: Marathon networking mode

networking-mode.ex

# Marathon 1.5+: there is a `networks` field
# Networking modes can't be mixed so using the first one is fine
def networking_mode(%{"networks" => [network | _]} = _app_json),
  do: network |> Map.get("mode", "container") |> String.to_existing_atom()

# Pre-Marathon 1.5 Docker container networking mode
def networking_mode(%{"container" => %{"docker" => %{"network" => "USER"}}}),
  do: :container

def networking_mode(%{"container" => %{"docker" => %{"network" => "BRIDGE"}}}),
  do: :"container/bridge"

# Otherwise, give up and default to host networking mode
def networking_mode(_), do: :host