hgweb: log error before attempting I/O
Previously, an uncaught exception during HTTP request serving would
attempt to send an error response then log the exception.
If an exception occurred during I/O, this exception would be
raised and the original exception wouldn't be logged.
This commit changes behavior so the original exception is logged
first, before we attempt to do anything else. This ensures the
exception is logged.
This change resulted in new tracebacks appearing in various tests.
Because tracebacks can vary between Python versions, we added a
simple script to filter the stack part of traceback lines. This
makes testing much simpler, as we don't need to glob over lines
and make lines conditional.
Differential Revision: https://phab.mercurial-scm.org/D5749
--- a/mercurial/hgweb/server.py Tue Jan 29 11:51:19 2019 -0800
+++ b/mercurial/hgweb/server.py Wed Jan 30 11:44:34 2019 -0800
@@ -101,9 +101,8 @@
try:
self.do_write()
except Exception:
- self._start_response(r"500 Internal Server Error", [])
- self._write(b"Internal Server Error")
- self._done()
+ # I/O below could raise another exception. So log the original
+ # exception first to ensure it is recorded.
tb = r"".join(traceback.format_exception(*sys.exc_info()))
# We need a native-string newline to poke in the log
# message, because we won't get a newline when using an
@@ -112,6 +111,10 @@
self.log_error(r"Exception happened during processing "
r"request '%s':%s%s", self.path, newline, tb)
+ self._start_response(r"500 Internal Server Error", [])
+ self._write(b"Internal Server Error")
+ self._done()
+
def do_PUT(self):
self.do_POST()
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/filtertraceback.py Wed Jan 30 11:44:34 2019 -0800
@@ -0,0 +1,29 @@
+#!/usr/bin/env python
+
+# Filters traceback lines from stdin.
+
+from __future__ import absolute_import, print_function
+
+import sys
+
+state = 'none'
+
+for line in sys.stdin:
+ if state == 'none':
+ if line.startswith('Traceback '):
+ state = 'tb'
+
+ elif state == 'tb':
+ if line.startswith(' File '):
+ state = 'file'
+ continue
+
+ elif not line.startswith(' '):
+ state = 'none'
+
+ elif state == 'file':
+ # Ignore lines after " File "
+ state = 'tb'
+ continue
+
+ print(line, end='')
--- a/tests/test-hgweb.t Tue Jan 29 11:51:19 2019 -0800
+++ b/tests/test-hgweb.t Wed Jan 30 11:44:34 2019 -0800
@@ -910,7 +910,20 @@
errors
- $ cat errors.log
+ $ cat errors.log | "$PYTHON" $TESTDIR/filtertraceback.py
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=spam': (glob)
+ Traceback (most recent call last):
+ error: [Errno 104] $ECONNRESET$
+
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/spam': (glob)
+ Traceback (most recent call last):
+ error: [Errno 104] $ECONNRESET$
+
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/spam/tip/foo': (glob)
+ Traceback (most recent call last):
+ error: [Errno 104] $ECONNRESET$
+
+ $ rm -f errors.log
Uncaught exceptions result in a logged error and canned HTTP response
@@ -925,8 +938,11 @@
[1]
$ killdaemons.py
- $ head -1 errors.log
+ $ cat errors.log | "$PYTHON" $TESTDIR/filtertraceback.py
.* Exception happened during processing request '/raiseerror': (re)
+ Traceback (most recent call last):
+ AttributeError: I am an uncaught error!
+
Uncaught exception after partial content sent
--- a/tests/test-http-bad-server.t Tue Jan 29 11:51:19 2019 -0800
+++ b/tests/test-http-bad-server.t Wed Jan 30 11:44:34 2019 -0800
@@ -207,7 +207,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(329 from 65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(296 from -1) -> (27) Accept-Encoding: identity\r\n
readline(269 from -1) -> (35) accept: application/mercurial-0.1\r\n
@@ -241,6 +241,10 @@
readline(* from -1) -> (2) \r\n (glob)
read(* from 28) -> (*) cmds=* (glob)
read limit reached, closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=batch': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after receiving N bytes
+
write(36) -> HTTP/1.1 500 Internal Server Error\r\n
$ rm -f error.log
@@ -258,7 +262,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(-1) -> (27) Accept-Encoding: identity\r\n
readline(-1) -> (35) accept: application/mercurial-0.1\r\n
@@ -267,6 +271,10 @@
readline(-1) -> (2) \r\n
write(1 from 36) -> (0) H
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=capabilities': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(36) -> HTTP/1.1 500 Internal Server Error\r\n
$ rm -f error.log
@@ -283,7 +291,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(-1) -> (27) Accept-Encoding: identity\r\n
readline(-1) -> (35) accept: application/mercurial-0.1\r\n
@@ -298,6 +306,10 @@
write(2 from 2) -> (20) \r\n
write(20 from 450) -> (0) batch branchmap bund
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=capabilities': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
$ rm -f error.log
@@ -318,7 +330,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(-1) -> (27) Accept-Encoding: identity\r\n
readline(-1) -> (35) accept: application/mercurial-0.1\r\n
@@ -346,6 +358,10 @@
write(37 from 37) -> (22) Date: $HTTP_DATE$\r\n
write(22 from 41) -> (0) Content-Type: applicat
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=batch': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(36) -> HTTP/1.1 500 Internal Server Error\r\n
$ rm -f error.log
@@ -366,7 +382,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(-1) -> (27) Accept-Encoding: identity\r\n
readline(-1) -> (35) accept: application/mercurial-0.1\r\n
@@ -397,6 +413,10 @@
write(2 from 2) -> (24) \r\n
write(24 from 42) -> (0) 96ee1d7354c4ad7372047672
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=batch': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
$ rm -f error.log
@@ -418,7 +438,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(-1) -> (27) Accept-Encoding: identity\r\n
readline(-1) -> (35) accept: application/mercurial-0.1\r\n
@@ -462,6 +482,10 @@
write(37 from 37) -> (33) Date: $HTTP_DATE$\r\n
write(33 from 41) -> (0) Content-Type: application/mercuri
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(36) -> HTTP/1.1 500 Internal Server Error\r\n
$ rm -f error.log
@@ -478,10 +502,10 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -4 error.log
- write(41 from 41) -> (25) Content-Type: application/mercurial-0.2\r\n
- write(25 from 28) -> (0) Transfer-Encoding: chunke
- write limit reached; closing socket
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -4
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(36) -> HTTP/1.1 500 Internal Server Error\r\n
$ rm -f error.log
@@ -499,7 +523,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(-1) -> (27) Accept-Encoding: identity\r\n
readline(-1) -> (35) accept: application/mercurial-0.1\r\n
@@ -545,6 +569,10 @@
write(28 from 28) -> (2) Transfer-Encoding: chunked\r\n
write(2 from 2) -> (0) \r\n
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(36) -> HTTP/1.1 500 Internal Server Error\r\n
$ rm -f error.log
@@ -562,7 +590,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ cat error.log
+ $ cat error.log | "$PYTHON" $TESTDIR/filtertraceback.py
readline(65537) -> (33) GET /?cmd=capabilities HTTP/1.1\r\n
readline(-1) -> (27) Accept-Encoding: identity\r\n
readline(-1) -> (35) accept: application/mercurial-0.1\r\n
@@ -611,6 +639,10 @@
write(9 from 9) -> (9) 4\r\nnone\r\n
write(9 from 9) -> (0) 4\r\nHG20\r\n
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -628,13 +660,17 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -7 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -11
write(28 from 28) -> (23) Transfer-Encoding: chunked\r\n
write(2 from 2) -> (21) \r\n
write(6 from 6) -> (15) 1\\r\\n\x04\\r\\n (esc)
write(9 from 9) -> (6) 4\r\nnone\r\n
write(6 from 9) -> (0) 4\r\nHG2
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -652,7 +688,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -8 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -12
write(28 from 28) -> (32) Transfer-Encoding: chunked\r\n
write(2 from 2) -> (30) \r\n
write(6 from 6) -> (24) 1\\r\\n\x04\\r\\n (esc)
@@ -660,6 +696,10 @@
write(9 from 9) -> (6) 4\r\nHG20\r\n
write(6 from 9) -> (0) 4\\r\\n\x00\x00\x00 (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -677,7 +717,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -8 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -12
write(28 from 28) -> (35) Transfer-Encoding: chunked\r\n
write(2 from 2) -> (33) \r\n
write(6 from 6) -> (27) 1\\r\\n\x04\\r\\n (esc)
@@ -685,6 +725,10 @@
write(9 from 9) -> (9) 4\r\nHG20\r\n
write(9 from 9) -> (0) 4\\r\\n\x00\x00\x00\x00\\r\\n (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -702,7 +746,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -9 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -13
write(28 from 28) -> (44) Transfer-Encoding: chunked\r\n
write(2 from 2) -> (42) \r\n
write(6 from 6) -> (36) 1\\r\\n\x04\\r\\n (esc)
@@ -711,6 +755,10 @@
write(9 from 9) -> (9) 4\\r\\n\x00\x00\x00\x00\\r\\n (esc)
write(9 from 9) -> (0) 4\\r\\n\x00\x00\x00)\\r\\n (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -731,7 +779,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -10 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -14
write(28 from 28) -> (91) Transfer-Encoding: chunked\r\n
write(2 from 2) -> (89) \r\n
write(6 from 6) -> (83) 1\\r\\n\x04\\r\\n (esc)
@@ -741,6 +789,10 @@
write(9 from 9) -> (47) 4\\r\\n\x00\x00\x00)\\r\\n (esc)
write(47 from 47) -> (0) 29\\r\\n\x0bCHANGEGROUP\x00\x00\x00\x00\x01\x01\x07\x02 \x01version02nbchanges1\\r\\n (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -761,7 +813,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -11 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -15
write(2 from 2) -> (110) \r\n
write(6 from 6) -> (104) 1\\r\\n\x04\\r\\n (esc)
write(9 from 9) -> (95) 4\r\nnone\r\n
@@ -772,6 +824,10 @@
write(9 from 9) -> (12) 4\\r\\n\x00\x00\x01\xd2\\r\\n (esc)
write(12 from 473) -> (0) 1d2\\r\\n\x00\x00\x00\xb2\x96\xee\x1d (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -792,7 +848,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -12 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -16
write(28 from 28) -> (573) Transfer-Encoding: chunked\r\n
write(2 from 2) -> (571) \r\n
write(6 from 6) -> (565) 1\\r\\n\x04\\r\\n (esc)
@@ -804,6 +860,10 @@
write(9 from 9) -> (473) 4\\r\\n\x00\x00\x01\xd2\\r\\n (esc)
write(473 from 473) -> (0) 1d2\\r\\n\x00\x00\x00\xb2\x96\xee\x1dsT\xc4\xadsr\x04vr\xc3j\x1fV\x1e:jL\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x96\xee\x1dsT\xc4\xadsr\x04vr\xc3j\x1fV\x1e:jL\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00>6a3df4de388f3c4f8e28f4f9a814299a3cbb5f50\\ntest\\n0 0\\nfoo\\n\\ninitial\x00\x00\x00\x00\x00\x00\x00\xa1j=\xf4\xde8\x8f<O\x8e(\xf4\xf9\xa8\x14)\x9a<\xbb_P\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x96\xee\x1dsT\xc4\xadsr\x04vr\xc3j\x1fV\x1e:jL\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00-foo\x00b80de5d138758541c5f05265ad144ab9fa86d1db\\n\x00\x00\x00\x00\x00\x00\x00\x07foo\x00\x00\x00h\xb8\\r\xe5\xd18u\x85A\xc5\xf0Re\xad\x14J\xb9\xfa\x86\xd1\xdb\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x96\xee\x1dsT\xc4\xadsr\x04vr\xc3j\x1fV\x1e:jL\x00\x00\x00\x00\x00\x00\x00\x00\\r\\n (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -827,7 +887,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -13 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -17
write(6 from 6) -> (596) 1\\r\\n\x04\\r\\n (esc)
write(9 from 9) -> (587) 4\r\nnone\r\n
write(9 from 9) -> (578) 4\r\nHG20\r\n
@@ -840,6 +900,10 @@
write(9 from 9) -> (13) 4\\r\\n\x00\x00\x00 \\r\\n (esc)
write(13 from 38) -> (0) 20\\r\\n\x08LISTKEYS (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -863,7 +927,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -22 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -26
write(9 from 9) -> (851) 4\\r\\n\x00\x00\x00\x00\\r\\n (esc)
write(9 from 9) -> (842) 4\\r\\n\x00\x00\x00)\\r\\n (esc)
write(47 from 47) -> (795) 29\\r\\n\x0bCHANGEGROUP\x00\x00\x00\x00\x01\x01\x07\x02 \x01version02nbchanges1\\r\\n (esc)
@@ -885,6 +949,10 @@
write(9 from 9) -> (9) 4\\r\\n\x00\x00\x00\x00\\r\\n (esc)
write(9 from 9) -> (0) 4\\r\\n\x00\x00\x00\x00\\r\\n (esc)
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log
@@ -907,7 +975,7 @@
$ killdaemons.py $DAEMON_PIDS
- $ tail -23 error.log
+ $ "$PYTHON" $TESTDIR/filtertraceback.py < error.log | tail -27
write(9 from 9) -> (854) 4\\r\\n\x00\x00\x00\x00\\r\\n (esc)
write(9 from 9) -> (845) 4\\r\\n\x00\x00\x00)\\r\\n (esc)
write(47 from 47) -> (798) 29\\r\\n\x0bCHANGEGROUP\x00\x00\x00\x00\x01\x01\x07\x02 \x01version02nbchanges1\\r\\n (esc)
@@ -930,6 +998,10 @@
write(9 from 9) -> (3) 4\\r\\n\x00\x00\x00\x00\\r\\n (esc)
write(3 from 5) -> (0) 0\r\n
write limit reached; closing socket
+ $LOCALIP - - [$ERRDATE$] Exception happened during processing request '/?cmd=getbundle': (glob)
+ Traceback (most recent call last):
+ Exception: connection closed after sending N bytes
+
write(27) -> 15\r\nInternal Server Error\r\n
$ rm -f error.log