defmodule PhoenixKitWeb.Plugs.MaintenanceMode do
@moduledoc """
Plug that enforces maintenance mode for non-admin users on controller routes.
LiveView routes are handled by the on_mount hook in `auth.ex` which overrides
the layout instead of redirecting. This plug handles the remaining non-LiveView
routes (POST actions, OAuth callbacks, etc.) by rendering a 503 maintenance page.
Adds a `Retry-After` header when a scheduled end time is known.
"""
import Plug.Conn
alias PhoenixKit.Modules.Maintenance
alias PhoenixKit.Users.Auth
alias PhoenixKit.Users.Auth.Scope
def init(opts), do: opts
def call(conn, _opts) do
# Clean up stale state if the scheduled end time has passed
Maintenance.cleanup_expired_schedule()
if Maintenance.active?() do
handle_maintenance_mode(conn)
else
conn
end
end
defp handle_maintenance_mode(conn) do
if should_skip?(conn.request_path) do
conn
else
user = get_user_from_session(conn)
if admin_or_owner?(user) do
conn
else
render_maintenance_page(conn)
end
end
end
defp should_skip?(path) do
static_asset?(path) or auth_route?(path)
end
defp static_asset?(path) do
String.starts_with?(path, "/assets/") or
String.starts_with?(path, "/images/") or
String.starts_with?(path, "/fonts/") or
String.starts_with?(path, "/favicon")
end
defp auth_route?(path) do
url_prefix = PhoenixKit.Config.get_url_prefix()
prefix_path = fn route ->
case url_prefix do
"" -> route
"/" -> route
prefix -> prefix <> route
end
end
auth_routes = [
"/users/log-in",
"/users/reset-password",
"/users/confirm",
"/users/magic-link",
"/users/auth/"
]
# Use starts_with? (not contains?) to prevent parent-app paths like
# "/blog/users/log-in-to-us" from bypassing maintenance mode.
Enum.any?(auth_routes, fn route ->
String.starts_with?(path, prefix_path.(route)) or
String.starts_with?(path, route)
end)
end
defp admin_or_owner?(nil), do: false
defp admin_or_owner?(user) do
scope = Scope.for_user(user)
Scope.admin?(scope) || Scope.owner?(scope)
end
defp get_user_from_session(conn) do
if user_token = get_session(conn, :user_token) do
Auth.get_user_by_session_token(user_token)
else
nil
end
end
defp render_maintenance_page(conn) do
config = Maintenance.get_config()
header = Phoenix.HTML.html_escape(config.header) |> Phoenix.HTML.safe_to_string()
subtext = Phoenix.HTML.html_escape(config.subtext) |> Phoenix.HTML.safe_to_string()
# Inline styles so the page works without the parent app's asset pipeline.
# Controller routes served by this plug may not have access to the digested
# app.css, so we ship a self-contained page.
html = """
#{header}
🚧
#{header}
#{subtext}
"""
conn
|> maybe_add_retry_after()
|> put_resp_content_type("text/html")
|> send_resp(:service_unavailable, html)
|> halt()
end
defp maybe_add_retry_after(conn) do
case Maintenance.seconds_until_end() do
seconds when is_integer(seconds) and seconds > 0 ->
put_resp_header(conn, "retry-after", Integer.to_string(seconds))
_ ->
conn
end
end
end