We have been using haproxy to balance a not very well written application
(http://www.blackboard.com/). Using the "insert postonly indirect" cookie
method, I was attempting to remove the cookie when users would logout,
allowing the machine to re-balance for the next user (this application is
used in school computer labs, so a computer might stay on the whole day
but be used on and off).
I was having a lot of trouble because when the cookie was set, it was with
"Path=/", but when being cleared there was no "Path" in the set cookie
header, and because the logout page was in a different place of the
website (which I couldn't change), the cookie would not be cleared. I
don't know if this would be a problem for anyone other than me (as our
HTTP application is so un-adjustable), but just in case, I have included
the patch I used. Maybe it will help someone else.
[ WT: this was a correct fix, and I also added the same missing path to
the set-cookie option ]
It's sometimes convenient to know if a proxy has processed any connection
at all when stopping it. Since a soft restart causes the "Proxy stopped"
message to be logged for each proxy, let's add the number of connections
so that it's possible afterwards to check whether a proxy had received
any connection.
Often we need to understand why some transfers were aborted or what
constitutes server response errors. With those two counters, it is
now possible to detect an unexpected transfer abort during a data
phase (eg: too short HTTP response), and to know what part of the
server response errors may in fact be assigned to aborted transfers.
Holger Just and Ross West reported build issues on FreeBSD and
Solaris that were initially caused by the definition of
_XOPEN_SOURCE at the top of auth.c, which was required on Linux
to avoid a build warning.
Krzysztof Oledzki found that using _GNU_SOURCE instead also worked
on Linux and did not cause any issue on several versions of FreeBSD.
Solaris still reported a warning this time, which was fixed by
including <crypt.h>, which itself is not present on FreeBSD nor on
all Linux toolchains.
So by adding a new build option (NEED_CRYPT_H), we can get Solaris
to get crypt() working and stop complaining at the same time, without
impacting other platforms.
This fix was tested at least on several linux toolchains (at least
uclibc, glibc 2.2.5, 2.3.6 and 2.7), on FreeBSD 4 to 8, Solaris 8
(which needs crypt.h), and AIX 5.3 (without crypt.h).
Every time it builds without a warning.
A copy-paste typo and a missing check were causing the logs to
report "PR" instead of "SD" when a server closes before sending
full data. Also, the log would erroneously report 502 while in
fact the correct response will already have been transmitted.
Some people have reported seeing "SL" flags in their logs quite often while
this should never happen. The reason was that then a server error is detected,
we close the connection to that server and when we decide what state we were
in, we see the connection is closed, and deduce it was the last data transfer,
which is wrong. We should report DATA if the previous state was an established
state, which this patch does.
Now logs correctly report "SD" and not "SL" when a server resets a connection
before the end of the transfer.
isalnum, isdigit and friends are really annoying because they take
an int in which we should pass an unsigned char, while strings
everywhere use chars. Solaris uses macros relying on an array for
those functions, which easily triggers some warnings showing where
we have mistakenly passed a char instead of an unsigned char or an
int. Those warnings may indicate real bugs on some platforms
depending on the implementation.
There are many information available in the stats page that can only
be seen when the mouse hovers over them. But it's hard to know where
those information are. Now with a discrete dotted underline it's easier
to spot those areas.
The current and max request rates are now reported when the mouse flies
over the session rate cur/max. The total requests is displayed with the
status codes over the total sessions cell.
The bounce realign function was algorithmically good but as expected
it was not cache-friendly. Using it with large requests caused so many
cache thrashing that the function itself could drain 70% of the total
CPU time for only 0.5% of the calls !
Revert back to a standard memcpy() using a specially allocated swap
buffer. We're now back to 2M req/s on pipelined requests.
It is wrong to merge FE and BE stats for a proxy because when we consult a
BE's stats, it reflects the FE's stats eventhough the BE has received no
traffic. The most common example happens with listen instances, where the
backend gets credited for all the trafic even when a use_backend rule makes
use of another backend.
The trash buffer may now be smaller than a buffer because we can tune
it at run time. This causes a risk when we're trying to use it as a
temporary buffer to realign unaligned requests, because we may have to
put up to a full buffer into it.
Instead of doing a double copy, we're now relying on an open-coded
bouncing copy algorithm. The principle is that we move one byte at
a time to its final place, and if that place also holds a byte, then
we move it too, and so on. We finish when we've moved all the buffer.
It limits the number of memory accesses, but since it proceeds one
byte at a time and with random walk, it's not cache friendly and
should be slower than a double copy. However, it's only used in
extreme situations and the difference will not be noticeable.
It has been extensively tested and works reliably.
When a host name could not be resolved, an alert was emitted but the
service used to start with 0.0.0.0 for the IP address, because the
address parsing functions could not report an error. This is now
changed. This fix must be backported to 1.3 as it was first discovered
there.
[WT: it was not a bug, I did it on purpose to leave no hole between IDs,
though it's not very practical when admins want to force some entries
after they have been used, because they'd rather leave a hole than
renumber everything ]
Forcing some of IDs should not shift others.
Regression introduced in 53fb4ae261b6e0e33e618f5cabbacc1657c19cc5
---cut here---
global
stats socket /home/ole/haproxy.stat user ole group ole mode 660
frontend F1
bind 127.0.0.1:9999
mode http
backend B1
mode http
backend B2
mode http
id 9999
backend B3
mode http
backend B4
mode http
---cut here---
Before 53fb4ae261b6e0e33e618f5cabbacc1657c19cc5:
$ echo "show stat" | socat unix-connect:/home/ole/haproxy.stat stdio|cut -d , -f 28
iid
1
2
9999
4
5
After 53fb4ae261b6e0e33e618f5cabbacc1657c19cc5:
$ echo "show stat" | socat unix-connect:/home/ole/haproxy.stat stdio|cut -d , -f 28
iid
1
2
9999
3
4
With this patch:
$ echo "show stat" | socat unix-connect:/home/ole/haproxy.stat stdio|cut -d , -f 28
iid
1
2
9999
4
5
Thich patch fixes cfgparser not to leak memory on each
default server statement and adds several missing free
calls in deinit():
- free(l->name)
- free(l->counters)
- free(p->desc);
- free(p->fwdfor_hdr_name);
None of them are critical, hopefully.
Released version 1.4-rc1 with the following main changes :
- [MEDIUM] add a maintenance mode to servers
- [MINOR] http-auth: last fix was wrong
- [CONTRIB] add base64rev-gen.c that was used to generate the base64rev table.
- [MINOR] Base64 decode
- [MINOR] generic auth support with groups and encrypted passwords
- [MINOR] add ACL_TEST_F_NULL_MATCH
- [MINOR] http-request: allow/deny/auth support for frontend/backend/listen
- [MINOR] acl: add http_auth and http_auth_group
- [MAJOR] use the new auth framework for http stats
- [DOC] add info about userlists, http-request and http_auth/http_auth_group acls
- [STATS] make it possible to change a CLI connection timeout
- [BUG] patterns: copy-paste typo in type conversion arguments
- [MINOR] pattern: make the converter more flexible by supporting void* and int args
- [MINOR] standard: str2mask: string to netmask converter
- [MINOR] pattern: add support for argument parsers for converters
- [MINOR] pattern: add the "ipmask()" converting function
- [MINOR] config: off-by-one in "stick-table" after list of converters
- [CLEANUP] acl, patterns: make use of my_strndup() instead of malloc+memcpy
- [BUG] restore accidentely removed line in last patch !
- [MINOR] checks: make the HTTP check code add the CRLF itself
- [MINOR] checks: add the server's status in the checks
- [BUILD] halog: make without arch-specific optimizations
- [BUG] halog: fix segfault in case of empty log in PCT mode (cherry picked from commit fe362fe4762151d209b9656639ee1651bc2b329d)
- [MINOR] http: disable keep-alive when process is going down
- [MINOR] acl: add build_acl_cond() to make it easier to add ACLs in config
- [CLEANUP] config: use build_acl_cond() instead of parse_acl_cond()
- [CLEANUP] config: use warnif_cond_requires_resp() to check for bad ACLs
- [MINOR] prepare req_*/rsp_* to receive a condition
- [CLEANUP] config: specify correct const char types to warnif_* functions
- [MEDIUM] config: factor out the parsing of 20 req*/rsp* keywords
- [MEDIUM] http: make the request filter loop check for optional conditions
- [MEDIUM] http: add support for conditional request filter execution
- [DOC] add some build info about the AIX platform (cherry picked from commit e41914c77edbc40aebf827b37542d37d758e371e)
- [MEDIUM] http: add support for conditional request header addition
- [MEDIUM] http: add support for conditional response header rewriting
- [DOC] add some missing ACLs about response header matching
- [MEDIUM] http: add support for proxy authentication
- [MINOR] http-auth: make the 'unless' keyword work as expected
- [CLEANUP] config: use build_acl_cond() to simplify http-request ACL parsing
- [MEDIUM] add support for anonymous ACLs
- [MEDIUM] http: switch to tunnel mode after status 101 responses
- [MEDIUM] http: stricter processing of the CONNECT method
- [BUG] config: reset check request to avoid double free when switching to ssl/sql
- [MINOR] config: fix too large ssl-hello-check message.
- [BUG] fix error response in case of server error
The fix below was incomplete :
commit d5fd51c75be6479539228f84377622a986b23be2
[BUG] http_server_error() must not purge a previous pending response
This can cause parts of responses to be truncated in case of
pipelined requests if the second request generates an error
before the first request is completely flushed.
Pending response data being rejected was still sent, causing inappropriate
error responses in case of error while parsing a response header. We must
purge pending data from the response buffer that were not scheduled to be
sent (l - send_max).
SSL and SQL checks did only perform a free() of the request without replacing
it, so having multiple SSL/SQL check declarations after another check type
causes a double free condition during config parsing. This should be backported
although it's harmless.
Now we establish the tunnel only once the status 200 reponse is
received. That way we can still support an authentication request
in response to a CONNECT, then a client's authentication response.
A 101 response is accompanied with an Upgrade header indicating
a new protocol that is spoken on the connection after the exchange
completes. At least we should switch to tunnel mode after such a
response.
Anonymous ACLs allow the declaration of rules which rely directly on
ACL expressions without passing via the declaration of an ACL. Example :
With named ACLs :
acl site_dead nbsrv(dynamic) lt 2
acl site_dead nbsrv(static) lt 2
monitor fail if site_dead
With anonymous ACLs :
monitor fail if { nbsrv(dynamic) lt 2 } || { nbsrv(static) lt 2 }
I'm not sure if the fix is correct:
- if (req_acl->cond)
- ret = acl_exec_cond(req_acl->cond, px, s, txn, ACL_DIR_REQ);
+ if (!req_acl->cond)
+ continue;
Doesn't it ignore rules with no condition attached? I think that the
proper solution would be the following.
One check was missing for the 'polarity' of the test. Now 'unless'
works. BTW, 'unless' provides a nice way to perform one-line auth :
acl valid-user http_auth(user-list)
http-request auth unless valid-user
This is a first attempt to add a maintenance mode on servers, using
the stat socket (in admin level).
It can be done with the following command :
- disable server <backend>/<server>
- enable server <backend>/<server>
In this mode, no more checks will be performed on the server and it
will be marked as a special DOWN state (MAINT).
If some servers were tracking it, they'll go DOWN until the server
leaves the maintenance mode. The stats page and the CSV export also
display this special state.
This can be used to disable the server in haproxy before doing some
operations on this server itself. This is a good complement to the
"http-check disable-on-404" keyword and works in TCP mode.
We're already able to know if a request is a proxy request or a
normal one, and we have an option "http-use-proxy-header" which states
that proxy headers must be checked. So let's switch to use the proxy
authentication headers and responses when this option is set and we're
facing a proxy request. That allows haproxy to enforce auth in front
of a proxy.
Support the new syntax (http-request allow/deny/auth) in
http stats.
Now it is possible to use the same syntax is the same like in
the frontend/backend http-request access control:
acl src_nagios src 192.168.66.66
acl stats_auth_ok http_auth(L1)
stats http-request allow if src_nagios
stats http-request allow if stats_auth_ok
stats http-request auth realm LB
The old syntax is still supported, but now it is emulated
via private acls and an aditional userlist.
Add generic authentication & authorization support.
Groups are implemented as bitmaps so the count is limited to
sizeof(int)*8 == 32.
Encrypted passwords are supported with libcrypt and crypt(3), so it is
possible to use any method supported by your system. For example modern
Linux/glibc instalations support MD5/SHA-256/SHA-512 and of course classic,
DES-based encryption.
Implement Base64 decoding with a reverse table.
The function accepts and decodes classic base64 strings, which
can be composed from many streams as long each one is properly
padded, for example: SGVsbG8=IEhBUHJveHk=IQ==
Just as for the req* rules, we can now condition rsp* rules with ACLs.
ACLs match on response, so volatile request information cannot be used.
A warning is emitted if a configuration contains such an anomaly.
All the req* rules except the reqadd rules can now be specified with
an if/unless condition. If a condition is specified and does not match,
the filter is ignored. This is particularly useful with reqidel, reqirep
and reqtarpit.
From now on, if request filters have ACLs defined, these ACLs will be
evaluated to condition the filter. This will be used to conditionally
remove/rewrite headers based on ACLs.
A new function was added to take care of the common code between
all those keywords. This has saved 8 kB of object code and about
500 lines of source code. This has also permitted to spot and fix
minor bugs (allocated args that were never used).
The code could be factored even more but that would make it a bit
more complex which is not interesting at this stage.
Various tests have been performed, and the warnings and errors are
still correctly reported and everything seems to work as expected.
This function automatically builds a rule, considering the if/unless
statements, and automatically updates the proxy's acl_requires, the
condition's file and line.
Krzysztof Oledzki suggested to disable keep-alive when a process
is going down due to a reload, in order to avoid ever-lasting
sessions. This is a simple and very efficient solution as it
ensures that at most one more request will be handled on a
keep-alive connection after the process has received a SIGUSR1
signal.
