Log request and exceptions for handlers that use `escapeHttp` and `terminateConnection` #94

HeinrichApfelmus · 2016-12-07T22:17:11Z

When using escapeHttp or terminateConnection to serve a request, the Snap HTTP server will not make any attempt to log the request, or any exception that the handler may throw.

I would prefer if Snap logs the requested path and any exception that the handler might throw. I found this useful in my Threepenny-GUI project. See also HeinrichApfelmus/threepenny-gui#145 .

Here is a minimal complete test case for the reported behavior:

$ cat SnapTest.hs
{-# LANGUAGE OverloadedStrings #-}

import qualified Data.ByteString.Char8  as BS   (hPutStrLn)
import qualified Control.Exception      as E
import           Snap.Core              as Snap
import qualified Snap.Http.Server       as Snap
import           System.IO                      (stderr)

config = Snap.setErrorLog  (Snap.ConfigIoLog $ BS.hPutStrLn stderr)
       $ Snap.setAccessLog (Snap.ConfigIoLog $ BS.hPutStrLn stderr)
       $ Snap.defaultConfig

main = Snap.httpServe config $ route
  [ ("escape"   , Snap.escapeHttp $ \_ _ _ -> E.throw msg)
  , ("terminate", Snap.terminateConnection msg)]

msg = E.AssertionFailed "Hello?"

Request issued

$ curl http://0.0.0.0:8000
<!DOCTYPE html>
<html>
<head>
<title>Not found</title>
</head>
<body>
<code>No handler accepted "/"</code>
</body></html>
$ curl http://0.0.0.0:8000/escape

curl: (52) Empty reply from server
$ curl http://0.0.0.0:8000/terminate

curl: (52) Empty reply from server

and the corresponding log

$ runhaskell SnapTest.hs 
no port specified, defaulting to port 8000
Listening on http://0.0.0.0:8000
127.0.0.1 - - [07/Dec/2016:23:04:54 +0100] "GET / HTTP/1.1" 404 198 - "curl/7.30.0"

The second and third request have not generated any log entry.

The text was updated successfully, but these errors were encountered:

Wizek mentioned this issue Dec 12, 2016

Uncaught exceptions are silently discarded in 0.7.0.0 (while they are properly displayed in 0.6.0.5) HeinrichApfelmus/threepenny-gui#145

Closed

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Log request and exceptions for handlers that use `escapeHttp` and `terminateConnection` #94

Log request and exceptions for handlers that use `escapeHttp` and `terminateConnection` #94

HeinrichApfelmus commented Dec 7, 2016

Log request and exceptions for handlers that use escapeHttp and terminateConnection #94

Log request and exceptions for handlers that use escapeHttp and terminateConnection #94

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HeinrichApfelmus commented Dec 7, 2016

Log request and exceptions for handlers that use `escapeHttp` and `terminateConnection` #94

Log request and exceptions for handlers that use `escapeHttp` and `terminateConnection` #94