From cb84f9a03b2154ffde3e3dd26695c9662d1bfd08 Mon Sep 17 00:00:00 2001
From: Christopher <chris@entropealabs.com>
Date: Sat, 21 Mar 2020 20:03:32 -0500
Subject: [PATCH] make database configurable with env vars

---
 config/config.exs                             |  4 ---
 .../authentication/ensure_default_admin.ex    | 12 ++++++-
 lib/router/authentication/repo.ex             | 35 +++++++++++++++++++
 mix.exs                                       |  3 +-
 4 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index 1321bb3..e9dd402 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -18,7 +18,3 @@ config :wampex_router,
       list_nodes: {:erlang, :nodes, [:connected]}
     ]
   ]
-
-config :wampex_router,
-  ecto_repos: [Wampex.Router.Authentication.Repo],
-  keylen: 32
diff --git a/lib/router/authentication/ensure_default_admin.ex b/lib/router/authentication/ensure_default_admin.ex
index 6a72096..423b02c 100644
--- a/lib/router/authentication/ensure_default_admin.ex
+++ b/lib/router/authentication/ensure_default_admin.ex
@@ -3,17 +3,27 @@ defmodule Wampex.Router.Authentication.EnsureDefaultAdmin do
   require Logger
   use GenServer
 
-  alias Wampex.Router.Authentication.{Realm, Peer}
+  alias Wampex.Router.Authentication.{Peer, Realm, Repo}
+  @ecto_repos [Repo]
 
   def start_link(uri: uri, authid: authid, password: password) do
     GenServer.start_link(__MODULE__, {uri, authid, password})
   end
 
   def init({uri, authid, password}) do
+    ensure_migrations()
     %Realm{} = realm = Realm.create(uri: uri)
     %Peer{} = user = Peer.create(authid: authid, password: password, realm: realm)
     Logger.debug("Realm: #{inspect(realm)}")
     Logger.debug("Peer: #{inspect(user)}")
     :ignore
   end
+
+  defp ensure_migrations do
+    Logger.info("Ensuring tables have been migrated")
+
+    for repo <- @ecto_repos() do
+      {:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :up, all: true))
+    end
+  end
 end
diff --git a/lib/router/authentication/repo.ex b/lib/router/authentication/repo.ex
index e423625..44fac5f 100644
--- a/lib/router/authentication/repo.ex
+++ b/lib/router/authentication/repo.ex
@@ -2,4 +2,39 @@ defmodule Wampex.Router.Authentication.Repo do
   use Ecto.Repo,
     otp_app: :wampex_router,
     adapter: Ecto.Adapters.Postgres
+
+  alias __MODULE__
+  require Logger
+
+  def init(:runtime, config) do
+    config = update_config(config, :database, "AUTH_DATABASE_NAME", nil)
+    config = update_config(config, :hostname, "AUTH_DATABASE_HOSTAME", nil)
+    config = update_config(config, :port, "AUTH_DATABASE_PORT", &String.to_integer/1)
+    config = update_config(config, :username, "AUTH_DATABASE_USERNAME", nil)
+    {:ok, config}
+  end
+
+  def init(:supervisor, config) do
+    ensure_db_created(config)
+    {:ok, config}
+  end
+
+  def ensure_db_created(config) do
+    Logger.info("Ensuring DB exists")
+    r = Repo.__adapter__().storage_up(config)
+    Logger.info("DB Creation: #{inspect(r)}")
+  end
+
+  def update_config(config, key, env, format) do
+    case System.get_env(env) do
+      nil ->
+        config
+
+      val ->
+        Keyword.put(config, key, do_format(val, format))
+    end
+  end
+
+  def do_format(val, nil), do: val
+  def do_format(val, fmt), do: fmt.(val)
 end
diff --git a/mix.exs b/mix.exs
index d4bffb3..b52e3e7 100644
--- a/mix.exs
+++ b/mix.exs
@@ -31,7 +31,8 @@ defmodule Wampex.Router.MixProject do
 
   def application do
     [
-      extra_applications: [:logger]
+      extra_applications: [:logger],
+      env: [keylen: 32]
     ]
   end
 
-- 
2.45.3