Network.Wai.Graceful

 app req = do
     liftIO $ somethingImportant -- like threadDelay 100000000
     LBSResponse status200 [("Content-Type", "text/plain")] "Finished!"

 main = do
     gs <- initGraceful

     forkIO $ run 8000 (graceful gs app)

     waitForTermination >> gracefulShutdown 15 gs
     putStrLn "Bye!"

Documentation

initGraceful :: IO Graceful

data Graceful

Constructors

Graceful

Fields

activeConnections :: MVar Int

shutdownTrigger :: MVar Bool

graceful :: Graceful -> Application -> Application

WAI Middleware that keeps track of active connections and blocks further requests with HTTP503.

gracefulShutdown

Arguments

:: Int

Timeout in seconds.

-> Graceful

-> IO ()

Trigger shutdown and monitor progress.

waitForTermination :: IO ()

Wait for TERM signal.