add cluster init per pow-auth/pow_site#10

lib/philomena/application.ex

@@ -11,6 +11,9 @@ defmodule Philomena.Application do
       # Connect to cluster nodes
       {Cluster.Supervisor, [[philomena: [strategy: Cluster.Strategy.ErlangHosts]]]},
 
+      # Session storage
+      Philomena.MnesiaClusterSupervisor,
+
       # Start the Ecto repository
       Philomena.Repo,
 
@@ -22,10 +25,6 @@ defmodule Philomena.Application do
       Philomena.Servers.PiczelChannelUpdater,
       Philomena.Servers.Config,
 
-      # Session storage
-      {Pow.Store.Backend.MnesiaCache, extra_db_nodes: Node.list()},
-      Pow.Store.Backend.MnesiaCache.Unsplit,
-
       {Redix, name: :redix, host: Application.get_env(:philomena, :redis_host)},
       {Phoenix.PubSub, [name: Philomena.PubSub, adapter: Phoenix.PubSub.PG2]},
 

lib/philomena/mnesia_cluster_supervisor.ex

@@ -0,0 +1,17 @@
+defmodule Philomena.MnesiaClusterSupervisor do
+  use Supervisor
+
+  def start_link(init_arg) do
+    Supervisor.start_link(__MODULE__, init_arg, name: __MODULE__)
+  end
+
+  @impl true
+  def init(_init_arg) do
+    children = [
+      {Pow.Store.Backend.MnesiaCache, extra_db_nodes: Node.list()},
+      Pow.Store.Backend.MnesiaCache.Unsplit
+    ]
+
+    Supervisor.init(children, strategy: :one_for_one)
+  end
+end