defmodule PhoenixKitWeb.Plugs.EnsureOAuthConfig do
@moduledoc """
Plug that ensures OAuth configuration is loaded before processing OAuth requests.
This plug serves as a fallback safety mechanism for cases where:
- PhoenixKit.Supervisor starts AFTER parent application's Endpoint
- OAuthConfigLoader worker failed to load configuration
- Configuration was cleared or lost for any reason
## How It Works
1. Checks if Ueberauth has :providers configured
2. If configuration is missing or invalid, loads it synchronously
3. If loading fails, returns 503 Service Unavailable error
4. Otherwise, allows request to proceed normally
## Usage
Add this plug BEFORE Ueberauth plug in OAuth controller:
plug PhoenixKitWeb.Plugs.EnsureOAuthConfig
plug Ueberauth
## Why This Is Needed
Ueberauth plug expects :providers key to exist in application config.
If it's missing, Ueberauth.get_providers/2 fails with MatchError.
This plug prevents that error by ensuring configuration exists before
Ueberauth plug runs.
"""
import Plug.Conn
require Logger
alias PhoenixKit.Config
def init(opts), do: opts
def call(conn, _opts) do
case ensure_oauth_config() do
:ok ->
conn
{:error, reason} ->
Logger.error("OAuth configuration unavailable: #{inspect(reason)}")
conn
|> put_resp_content_type("text/html")
|> send_resp(503, """
Service Temporarily Unavailable
OAuth Service Unavailable
OAuth authentication is temporarily unavailable. Please try again later.
If this problem persists, please contact support.
""")
|> halt()
end
end
defp ensure_oauth_config do
providers = Config.UeberAuth.get_providers()
case providers do
providers when is_map(providers) or is_list(providers) ->
# Configuration exists, all good
:ok
_ ->
# Configuration missing, try to load it
Logger.warning("Ueberauth :providers missing, attempting to load OAuth configuration")
load_oauth_config()
end
end
defp load_oauth_config do
if Code.ensure_loaded?(PhoenixKit.Users.OAuthConfig) do
try do
alias PhoenixKit.Users.OAuthConfig
OAuthConfig.configure_providers()
Logger.info("OAuth configuration loaded successfully via fallback plug")
:ok
rescue
error ->
Logger.error("Failed to load OAuth configuration: #{inspect(error)}")
{:error, :configuration_load_failed}
end
else
Logger.error("PhoenixKit.Users.OAuthConfig module not available")
{:error, :oauth_module_not_loaded}
end
end
end