(feat) fly.io redirector to revenuelink.net

config/runtime.exs

@@ -24,6 +24,8 @@ config :revstack, RevstackWeb.Endpoint,
   http: [port: String.to_integer(System.get_env("PORT", "4000"))]
 
 if config_env() == :prod do
+  fly_app_name = System.get_env("FLY_APP_NAME")
+
   config :revstack, Revstack.Repo, Revstack.RepoConfig.prod_repo_config()
 
   # The secret key base is used to sign/encrypt cookies and other secrets.
@@ -66,6 +68,11 @@ if config_env() == :prod do
       System.get_env("ADMIN_PASSWORD") ||
         raise("Missing environment variable `ADMIN_PASSWORD`!")
 
+  config :revstack, RevstackWeb.Plugs.FlyRedirect,
+    enabled: not is_nil(fly_app_name),
+    source_host: "revstack.fly.dev",
+    target_url: "https://revenuelink.net"
+
   # Trust proxy headers (X-Forwarded-For) from Fly.io load balancer
   config :revstack, trust_proxy: true
 

fly.toml

@@ -7,6 +7,7 @@ app = "revstack"
 primary_region = "dfw"
 kill_signal = "SIGTERM"
 kill_timeout = "5s"
+swap_size_mb = 512
 
 [build]
 
@@ -22,17 +23,11 @@ kill_timeout = "5s"
 [http_service]
   internal_port = 8080
   force_https = true
-  auto_stop_machines = "stop"
+  auto_stop_machines = true
   auto_start_machines = true
-  min_machines_running = 1
+  min_machines_running = 0
   processes = ["app"]
-
   [http_service.concurrency]
     type = "connections"
     hard_limit = 1000
     soft_limit = 1000
-
-[[vm]]
-  memory = "1gb"
-  cpu_kind = "shared"
-  cpus = 1

lib/revstack_web/endpoint.ex

@@ -15,6 +15,8 @@ defmodule RevstackWeb.Endpoint do
     websocket: [connect_info: [session: @session_options]],
     longpoll: [connect_info: [session: @session_options]]
 
+  plug RevstackWeb.Plugs.FlyRedirect
+
   # Serve at "/" the static files from "priv/static" directory.
   #
   # When code reloading is disabled (e.g., in production),

lib/revstack_web/plugs/fly_redirect.ex

@@ -0,0 +1,36 @@
+defmodule RevstackWeb.Plugs.FlyRedirect do
+  @moduledoc """
+  Redirects requests from the Fly app domain to the canonical external site.
+
+  This plug is intended to run in production and is controlled via runtime config.
+  """
+
+  @behaviour Plug
+
+  import Plug.Conn
+
+  @impl true
+  def init(opts), do: opts
+
+  @impl true
+  def call(conn, _opts) do
+    redirect_config = Application.get_env(:revstack, __MODULE__, [])
+
+    enabled? = Keyword.get(redirect_config, :enabled, false)
+    source_host = Keyword.get(redirect_config, :source_host, "revstack.fly.dev")
+    target_url = Keyword.get(redirect_config, :target_url, "https://revenuelink.net")
+
+    if enabled? and host_matches?(conn.host, source_host) do
+      conn
+      |> put_resp_header("location", target_url)
+      |> send_resp(301, "")
+      |> halt()
+    else
+      conn
+    end
+  end
+
+  defp host_matches?(host, source_host) do
+    String.downcase(host || "") == String.downcase(source_host || "")
+  end
+end

mix.exs

@@ -4,7 +4,7 @@ defmodule Revstack.MixProject do
   def project do
     [
       app: :revstack,
-      version: "1.4.0",
+      version: "1.5.0",
       elixir: "~> 1.15",
       elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,

test/revstack_web/plugs/fly_redirect_test.exs

@@ -0,0 +1,68 @@
+defmodule RevstackWeb.Plugs.FlyRedirectTest do
+  use RevstackWeb.ConnCase, async: true
+
+  alias RevstackWeb.Plugs.FlyRedirect
+
+  describe "call/2" do
+    setup do
+      original_config = Application.get_env(:revstack, FlyRedirect, [])
+
+      on_exit(fn ->
+        Application.put_env(:revstack, FlyRedirect, original_config)
+      end)
+
+      :ok
+    end
+
+    test "redirects when enabled and host matches source host", %{conn: conn} do
+      Application.put_env(:revstack, FlyRedirect,
+        enabled: true,
+        source_host: "revstack.fly.dev",
+        target_url: "https://revenuelink.net"
+      )
+
+      conn =
+        conn
+        |> Map.put(:host, "revstack.fly.dev")
+        |> FlyRedirect.call([])
+
+      assert conn.halted
+      assert conn.status == 301
+      assert get_resp_header(conn, "location") == ["https://revenuelink.net"]
+    end
+
+    test "does not redirect when disabled", %{conn: conn} do
+      Application.put_env(:revstack, FlyRedirect,
+        enabled: false,
+        source_host: "revstack.fly.dev",
+        target_url: "https://revenuelink.net"
+      )
+
+      conn =
+        conn
+        |> Map.put(:host, "revstack.fly.dev")
+        |> FlyRedirect.call([])
+
+      refute conn.halted
+      assert conn.status == nil
+      assert get_resp_header(conn, "location") == []
+    end
+
+    test "does not redirect for non-matching host", %{conn: conn} do
+      Application.put_env(:revstack, FlyRedirect,
+        enabled: true,
+        source_host: "revstack.fly.dev",
+        target_url: "https://revenuelink.net"
+      )
+
+      conn =
+        conn
+        |> Map.put(:host, "example.com")
+        |> FlyRedirect.call([])
+
+      refute conn.halted
+      assert conn.status == nil
+      assert get_resp_header(conn, "location") == []
+    end
+  end
+end