From 1ddf9cbddd051894b2aabede01b65fa969b6d132 Mon Sep 17 00:00:00 2001
From: Nick Kezhaya <nick@whitepaperclip.com>
Date: Thu, 17 Oct 2019 17:25:15 -0500
Subject: [PATCH] Migrate on startup

---
 config/config.exs                             | 14 ----
 lib/stripe_mock/application.ex                |  3 +-
 lib/stripe_mock/migrator.ex                   | 73 +++++++++++++++++++
 lib/stripe_mock/repo.ex                       | 22 +++++-
 .../plug/ensure_migrator_finished.ex          | 11 +++
 lib/stripe_mock_web/router.ex                 |  1 +
 6 files changed, 108 insertions(+), 16 deletions(-)
 create mode 100644 lib/stripe_mock/migrator.ex
 create mode 100644 lib/stripe_mock_web/plug/ensure_migrator_finished.ex

diff --git a/config/config.exs b/config/config.exs
index 12dae8f..589bc42 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -24,20 +24,6 @@ config :logger, :console,
 # Use Jason for JSON parsing in Phoenix
 config :phoenix, :json_library, Jason
 
-{uri, _} = System.cmd("pg_tmp", ["-t"])
-
-[username, host, port, database] =
-  Regex.scan(~r/(\w+)@([\w\d\.]+)\:(\d+)\/(\w+)/i, uri, capture: :all_but_first) |> List.flatten()
-
-config :stripe_mock, StripeMock.Repo,
-  username: username,
-  password: "",
-  database: database,
-  hostname: host,
-  port: port,
-  pool_size: 2,
-  migration_primary_key: [name: :id, type: :binary_id]
-
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.
 import_config "#{Mix.env()}.exs"
diff --git a/lib/stripe_mock/application.ex b/lib/stripe_mock/application.ex
index b6a4e3f..ce6ef42 100644
--- a/lib/stripe_mock/application.ex
+++ b/lib/stripe_mock/application.ex
@@ -6,7 +6,8 @@ defmodule StripeMock.Application do
   def start(_type, _args) do
     children = [
       StripeMockWeb.Endpoint,
-      StripeMock.Repo
+      StripeMock.Repo,
+      StripeMock.Migrator
     ]
 
     opts = [strategy: :one_for_one, name: StripeMock.Supervisor]
diff --git a/lib/stripe_mock/migrator.ex b/lib/stripe_mock/migrator.ex
new file mode 100644
index 0000000..52bb8f7
--- /dev/null
+++ b/lib/stripe_mock/migrator.ex
@@ -0,0 +1,73 @@
+defmodule StripeMock.Migrator do
+  use GenServer
+
+  def start_link(default) do
+    GenServer.start_link(__MODULE__, default, name: __MODULE__)
+  end
+
+  def done? do
+    GenServer.call(__MODULE__, :done?)
+  end
+
+  @impl true
+  def init(_arg) do
+    migrate()
+
+    {:ok, nil}
+  end
+
+  @impl true
+  def handle_call(:done?, _from, state) do
+    {:reply, true, state}
+  end
+
+  @start_apps [
+    :crypto,
+    :ssl,
+    :postgrex,
+    :ecto,
+    :ecto_sql
+  ]
+
+  @repos [StripeMock.Repo]
+
+  def migrate(_argv \\ nil) do
+    # Start apps necessary for executing migrations
+    IO.puts("Starting dependencies")
+    Enum.each(@start_apps, &Application.ensure_all_started/1)
+
+    Application.load(:basic_space)
+
+    # Start the Repo(s) for app
+    # Switch pool_size to 2 for ecto > 3.0
+    IO.puts("Starting repos")
+    Enum.each(@repos, & &1.start_link(pool_size: 2))
+
+    # Run migrations
+    Enum.each(@repos, &run_migrations_for/1)
+
+    # Done
+    IO.puts("Success!")
+  end
+
+  defp run_migrations_for(repo) do
+    app = Keyword.get(repo.config, :otp_app)
+    migrations_path = priv_path_for(repo, "migrations")
+    IO.puts("Running migrations for #{app}, from #{migrations_path}")
+    Ecto.Migrator.run(repo, migrations_path, :up, all: true)
+  end
+
+  defp priv_path_for(repo, filename) do
+    app = Keyword.get(repo.config, :otp_app)
+
+    repo_underscore =
+      repo
+      |> Module.split()
+      |> List.last()
+      |> Macro.underscore()
+
+    priv_dir = "#{:code.priv_dir(app)}"
+
+    Path.join([priv_dir, repo_underscore, filename])
+  end
+end
diff --git a/lib/stripe_mock/repo.ex b/lib/stripe_mock/repo.ex
index 187555f..3a3e264 100644
--- a/lib/stripe_mock/repo.ex
+++ b/lib/stripe_mock/repo.ex
@@ -1,9 +1,29 @@
 defmodule StripeMock.Repo do
   use Ecto.Repo, otp_app: :stripe_mock, adapter: Ecto.Adapters.Postgres
   import Ecto.Changeset
-  alias Ecto.Changeset
   alias StripeMock.API
 
+  @impl true
+  def init(_type, config) do
+    {uri, _} = System.cmd("pg_tmp", ["-t"])
+
+    [[username, host, port, database]] =
+      Regex.scan(~r/(\w+)@([\w\d\.]+)\:(\d+)\/(\w+)/i, uri, capture: :all_but_first)
+
+    config =
+      Keyword.merge(config,
+        username: username,
+        password: "",
+        database: database,
+        hostname: host,
+        port: port,
+        pool_size: 2,
+        migration_primary_key: [name: :id, type: :binary_id]
+      )
+
+    {:ok, config}
+  end
+
   def fetch(schema, id) do
     with true <- valid_id?(id),
          %{} = object <- get(schema, id) do
diff --git a/lib/stripe_mock_web/plug/ensure_migrator_finished.ex b/lib/stripe_mock_web/plug/ensure_migrator_finished.ex
new file mode 100644
index 0000000..c057d1b
--- /dev/null
+++ b/lib/stripe_mock_web/plug/ensure_migrator_finished.ex
@@ -0,0 +1,11 @@
+defmodule StripeMockWeb.Plug.EnsureMigratorFinished do
+  def init(arg) do
+    arg
+  end
+
+  def call(conn, _arg) do
+    true = StripeMock.Migrator.done?()
+
+    conn
+  end
+end
diff --git a/lib/stripe_mock_web/router.ex b/lib/stripe_mock_web/router.ex
index 092fdc4..cdd1b6b 100644
--- a/lib/stripe_mock_web/router.ex
+++ b/lib/stripe_mock_web/router.ex
@@ -4,6 +4,7 @@ defmodule StripeMockWeb.Router do
   pipeline :api do
     plug :accepts, ["json"]
     plug StripeMockWeb.Plug.Auth
+    plug StripeMockWeb.Plug.EnsureMigratorFinished
   end
 
   scope "/v1", StripeMockWeb do