DNS selection preferences are actually declared inline in the
struct server. There are copied from the server struct to the
dns_resolution struct for each resolution.
Next patchs adds new preferences options, and it is not a good
way to copy all the configuration information before each dns
resolution.
This patch extract the configuration preference from the struct
server and declares a new dedicated struct. Only a pointer to this
new striuict will be copied before each dns resolution.
Servers state function save and apply server IP when DNS resolution is
enabled on a server.
Purpose is to prevent switching traffic from one server to an other one
when multiple IPs are returned by the DNS server for the A or AAAA
record.
That said, a bug in current code lead to erase the service port while
copying the IP found in the file into the server structure in HAProxy's
memory.
This patch fix this bug.
The bug was reported on the ML by Robert Samuel Newson and fix proposed
by Nenad Merdanovic.
Thank you both!!!
backport: can be backported to 1.6
A small configuration parsing error exists when no port is setup on the
server IP:port statement and the server's parameter 'port' is not set
and if the first tcp-check rule is a comment, like in the example below:
backend b
option tcp-check
tcp-check comment blah
tcp-check connect 8444
server s 127.0.0.1 check
In such case, an ALERT is improperly returned, despite this
configuration is valid and works.
The new code move the pointer to the first tcp-check rule which isn't a
comment before checking the presence of the port.
backport status: 1.6 and above
Current configuration parsing is permissive in such situation:
A server in a backend with no port conigured on the IP address
statement, no 'port' parameter configured and last rule of a tcp-check
is a CONNECT with no port.
The current code currently parses all the rules to validate a port is
well available, but it misses the last one, which means such
configuration is valid:
backend b
option tcp-check
tcp-check connect port 8444
tcp-check connect
server s 127.0.0.1 check
the second connect tentative is sent to port '0'...
Current patch fixes this by parsing the list the right way, including
the last rule.
backport status: 1.6 and above
fgets() can return NULL on error or when EOF occurs. This patch adds a
check of fgets() return value and displays a warning if the first line of
the server state file can not be read. Additionally, we make sure to close
the previously opened file descriptor.
Causes HAProxy to emit a static string to the agent on every check,
so that you can independently control multiple services running
behind a single agent port.
The status DNS_UPD_NAME_ERROR returned by dns_get_ip_from_response and
which means the queried name can't be found in the response was
improperly processed (fell into the default case).
This lead to a loop where HAProxy simply resend a new query as soon as
it got a response for this status and in the only case where such type
of response is the very first one received by the process.
This should be backported into 1.6 branch
Basically, it's ill-defined and shouldn't really be used going forward.
We can't guarantee that resolvers will do the 'legwork' for us and
actually resolve CNAMES when we request the ANY query-type. Case in point
(obfuscated, clearly):
PRODUCTION! ahayworth@secret-hostname.com:~$
dig @10.11.12.53 ANY api.somestartup.io
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> @10.11.12.53 ANY api.somestartup.io
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62454
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 4, ADDITIONAL: 0
;; QUESTION SECTION:
;api.somestartup.io. IN ANY
;; ANSWER SECTION:
api.somestartup.io. 20 IN CNAME api-somestartup-production.ap-southeast-2.elb.amazonaws.com.
;; AUTHORITY SECTION:
somestartup.io. 166687 IN NS ns-1254.awsdns-28.org.
somestartup.io. 166687 IN NS ns-1884.awsdns-43.co.uk.
somestartup.io. 166687 IN NS ns-440.awsdns-55.com.
somestartup.io. 166687 IN NS ns-577.awsdns-08.net.
;; Query time: 1 msec
;; SERVER: 10.11.12.53#53(10.11.12.53)
;; WHEN: Mon Oct 19 22:02:29 2015
;; MSG SIZE rcvd: 242
HAProxy can't handle that response correctly.
Rather than try to build in support for resolving CNAMEs presented
without an A record in an answer section (which may be a valid
improvement further on), this change just skips ANY record types
altogether. A and AAAA are much more well-defined and predictable.
Notably, this commit preserves the implicit "Prefer IPV6 behavior."
Furthermore, ANY query type by default is a bad idea: (from Robin on
HAProxy's ML):
Using ANY queries for this kind of stuff is considered by most people
to be a bad practice since besides all the things you named it can
lead to incomplete responses. Basically a resolver is allowed to just
return whatever it has in cache when it receives an ANY query instead
of actually doing an ANY query at the authoritative nameserver. Thus
if it only received queries for an A record before you do an ANY query
you will not get an AAAA record even if it is actually available since
the resolver doesn't have it in its cache. Even worse if before it
only got MX queries, you won't get either A or AAAA
Commit e11cfcd ("MINOR: config: new backend directives:
load-server-state-from-file and server-state-file-name") introduced a bug
which can cause haproxy to crash upon startup by sending user-controlled
data in a format string when emitting a warning. Fix the way the warning
message is built to avoid this.
No backport is needed, this was introduced in 1.6-dev6 only.
Commit e11cfcd ("MINOR: config: new backend directives:
load-server-state-from-file and server-state-file-name") caused these
warnings when building with Clang :
src/server.c:1972:21: warning: comparison of unsigned expression < 0 is always false [-Wtautological-compare]
(srv_uweight < 0) || (srv_uweight > SRV_UWGHT_MAX))
~~~~~~~~~~~ ^ ~
src/server.c:1980:21: warning: comparison of unsigned expression < 0 is always false [-Wtautological-compare]
(srv_iweight < 0) || (srv_iweight > SRV_UWGHT_MAX))
~~~~~~~~~~~ ^ ~
Indeed, srv_iweight and srv_uweight are unsigned. Just drop the offending test.
This patch uses the start up of the health check task to also start
the warmup task when required.
This is executed only once: when HAProxy has just started up and can
be started only if the load-server-state-from-file feature is enabled
and the server was in the warmup state before a reload occurs.
This directive gives HAProxy the ability to use the either the global
server-state-file directive or a local one using server-state-file-name to
load server states.
The state can be saved right before the reload by the init script, using
the "show servers state" command on the stats socket redirecting output into
a file.
When a server is disabled in the configuration using the "disabled"
keyword, a single flag is positionned: SRV_ADMF_CMAINT (use to be
SRV_ADMF_FMAINT)..
That said, when providing the first version of this code, we also
changed the SRV_ADMF_MAINT mask to match any of the possible MAINT
cases: SRV_ADMF_FMAINT, SRV_ADMF_IMAINT, SRV_ADMF_CMAINT
Since SRV_ADMF_CMAINT is never (and is not supposed to be) altered at
run time, once a server has this flag set up, it can never ever be
enabled again using the stats socket.
In order to fix this, we should:
- consider SRV_ADMF_CMAINT as a simple flag to report the state in the
old configuration file (will be used after a reload to deduce the
state of the server in a new running process)
- enabling both SRV_ADMF_CMAINT and SRV_ADMF_FMAINT when the keyword
"disabled" is in use in the configuration
- update the mask SRV_ADMF_MAINT as it was before, to only match
SRV_ADMF_FMAINT and SRV_ADMF_IMAINT.
The following patch perform the changes above.
It allows fixing the regression without breaking the way the up coming
feature (seamless server state accross reloads) is going to work.
Note: this is 1.6-only, no backport needed.
There are two types of retries when performing a DNS resolution:
1. retry because of a timeout
2. retry of the full sequence of requests (query types failover)
Before this patch, the 'resolution->try' counter was incremented
after each send of a DNS request, which does not cover the 2 cases
above.
This patch fix this behavior.
Some DNS response may be valid from a protocol point of view but may not
contain any IP addresses.
This patch gives a new flag to the function dns_get_ip_from_response to
report such case.
It's up to the upper layer to decide what to do with this information.
Some DNS responses may be valid from a protocol point of view, but may
not contain any information considered as interested by the requester..
Purpose of the flag DNS_RESP_NO_EXPECTED_RECORD introduced by this patch is
to allow reporting such situation.
When this happens, a new DNS query is sent with a new query type.
For now, the function only expect A and AAAA query types which is enough
to cover current cases.
In a next future, it will be up to the caller to tell the function which
query types are expected.
The server's host name picked for resolution was incorrect, it did not
skip the address family specifier, did not resolve environment variables,
and messed up with the optional trailing colon.
Instead, let's get the fqdn returned by str2sa_range() and use that
exclusively.
The function does a bunch of things among which resolving environment
variables, skipping address family specifiers and trimming port ranges.
It is the only one which sees the complete host name before trying to
resolve it. The DNS resolving code needs to know the original hostname,
so we modify this function to optionally provide it to the caller.
Note that the function itself doesn't know if the host part was a host
or an address, but str2ip() knows that and can be asked not to try to
resolve. So we first try to parse the address without resolving and
try again with resolving enabled. This way we know if the address is
explicit or needs some kind of resolution.
In the first version of the DNS resolver, HAProxy sends an ANY query
type and in case of issue fails over to the type pointed by the
directive in 'resolve-prefer'.
This patch allows the following new failover management:
1. default query type is still ANY
2. if response is truncated or in error because ANY is not supported by
the server, then a fail over to a new query type is performed. The
new query type is the one pointed by the directive 'resolve-prefer'.
3. if no response or still some errors occurs, then a query type fail over
is performed to the remaining IP address family.
This patch introduces a new internal response state about the analysis
of a DNS response received by a server.
It is dedicated to report to above layer that the response is
'truncated'.
Under certain circonstance (a configuration with many servers relying on
DNS resolution and one of them triggering the replay of a request
because of a timeout or invalid response to an ANY query), HAProxy could
end up in an infinite loop over the currently supposed running DNS
queries.
This was caused because the FIFO list of running queries was improperly
updated in snr_resolution_error_cb. The head of the list was removed
instead of the resolution in error, when moving the resolution to the
end of the list.
In the mean time, a LIST_DEL statement is removed since useless. This
action is already performed by the dns_reset_resolution function.
First DNS resolution is supposed to be triggered by first health check,
which is not the case with current code.
This patch fixes this behavior by setting the
resolution->last_resolution time to 0 instead of now_ms when parsing
server's configuration at startup.
This was the first transparent proxy technology supported by haproxy
circa 2005 but it was obsoleted in 2007 by Tproxy 4.0 which removed a
lot of the earlier versions' shortcomings and was finally merged into
the kernel. Since nobody has been using cttproxy for many years now
and nobody has even just tried to compile the files, it's time to
remove it. The doc was updated as well.
The newly created server flag SRV_ADMF_CMAINT means that the server is
in 'disabled' mode because of configuration statement 'disabled'.
The flag SRV_ADMF_FMAINT should not be set anymore in such case and is
reserved only when the server is Forced in maintenance mode from the
stats socket.
These ones are considered safe as they have already been reused.
They will be useful in "aggressive" and "always" http-reuse modes
in order to place the first request of a connection with the least
risk.
For now it's not populated but we have the list entry. It will carry
all idle connections that sessions don't want to share. They may be
used later to reclaim connections upon socket shortage for example.
This patch introduces three new functions which can be used to find a
server in a farm using different server information:
- server unique id (srv->puid)
- server name
- find best match using either name or unique id
When performing best matching, the following applies:
- use the server name first (if provided)
- use the server id if provided
in any case, the function can update the caller about mismatches
encountered.
This flag aims at reporting whether the server unique id (srv->puid) has
been forced by the administrator in HAProxy's configuration.
If not set, it means HAProxy has generated automatically the server's
unique id.
Ability to change a server IP address during HAProxy run time.
For now this is provided via function update_server_addr() which
currently is not called.
A log is emitted on each change. For now we do it inconditionally,
but later we'll want to do it only on certain circumstances, which
explains why the logging block is enclosed in if(1).
This is similar to the way email alerts are sent when servers are marked as
DOWN.
Like the log messages corresponding to these state changes the messages
have log level notice. Thus they are suppressed by the default email-alert
level of 'alert'. To allow these messages the email-alert level should
be set to 'notice', 'info' or 'debug'. e.g:
email-alert level notice
"email-alert mailers" and "email-alert to" settings are also required in
order for any email alerts to be sent.
A follow-up patch will document the above.
Signed-off-by: Simon Horman <horms@verge.net.au>
With HTTP/2, we'll have to support multiplexed streams. A stream is in
fact the largest part of what we currently call a session, it has buffers,
logs, etc.
In order to catch any error, this commit removes any reference to the
struct session and tries to rename most "session" occurrences in function
names to "stream" and "sess" to "strm" when that's related to a session.
The files stream.{c,h} were added and session.{c,h} removed.
The session will be reintroduced later and a few parts of the stream
will progressively be moved overthere. It will more or less contain
only what we need in an embryonic session.
Sample fetch functions and converters will have to change a bit so
that they'll use an L5 (session) instead of what's currently called
"L4" which is in fact L6 for now.
Once all changes are completed, we should see approximately this :
L7 - http_txn
L6 - stream
L5 - session
L4 - connection | applet
There will be at most one http_txn per stream, and a same session will
possibly be referenced by multiple streams. A connection will point to
a session and to a stream. The session will hold all the information
we need to keep even when we don't yet have a stream.
Some more cleanup is needed because some code was already far from
being clean. The server queue management still refers to sessions at
many places while comments talk about connections. This will have to
be cleaned up once we have a server-side connection pool manager.
Stream flags "SN_*" still need to be renamed, it doesn't seem like
any of them will need to move to the session.
When the destination IP is dynamically set, we can't use the "target"
to define the proto. This patch ensures that we always use the protocol
associated with the address family. The proto field was removed from
the server and check structs.
This patch adds a new option which allows configuration of the maximum
log level of messages for which email alerts will be sent.
The default is alert which is more restrictive than
the current code which sends email alerts for all priorities.
That behaviour may be configured using the new configuration
option to set the maximum level to notice or greater.
email-alert level notice
Signed-off-by: Simon Horman <horms@verge.net.au>
This removes the trailing '.' from both the header and the body of email
alerts.
The main motivation for this change is to make the format of email alerts
generated from srv_set_stopped() consistent with those generated from
set_server_check_status().
Signed-off-by: Simon Horman <horms@verge.net.au>
The motivation for this is to make checks more independent of each
other to allow further reuse of their infrastructure.
For nowserver->check and server->agent still always use the same values
for the addr and proto fields so this patch should not introduce any
behavioural changes.
Signed-off-by: Simon Horman <horms@verge.net.au>
Refactor init_check so that an error string is returned
rather than alerts being printed by it. Also
init_check to checks.c and provide a prototype to allow
it to be used from multiple C files.
Signed-off-by: Simon Horman <horms@verge.net.au>
disable starts a server in the disabled state, however setting the health
of an agent implies that the agent is disabled as well as the server.
This is a problem because the state of the agent is not restored if
the state of the server is subsequently updated leading to an
unexpected state.
For example, if a server is started disabled and then the server
state is set to ready then without this change show stat indicates
that the server is "DOWN (agent)" when it is expected that the server
would be UP if its (non-agent) health check passes.
Reported-by: Mark Brooks <mark@loadbalancer.org>
Signed-off-by: Simon Horman <horms@verge.net.au>
This patch makes it possible to create binds and servers in separate
namespaces. This can be used to proxy between multiple completely independent
virtual networks (with possibly overlapping IP addresses) and a
non-namespace-aware proxy implementation that supports the proxy protocol (v2).
The setup is something like this:
net1 on VLAN 1 (namespace 1) -\
net2 on VLAN 2 (namespace 2) -- haproxy ==== proxy (namespace 0)
net3 on VLAN 3 (namespace 3) -/
The proxy is configured to make server connections through haproxy and sending
the expected source/target addresses to haproxy using the proxy protocol.
The network namespace setup on the haproxy node is something like this:
= 8< =
$ cat setup.sh
ip netns add 1
ip link add link eth1 type vlan id 1
ip link set eth1.1 netns 1
ip netns exec 1 ip addr add 192.168.91.2/24 dev eth1.1
ip netns exec 1 ip link set eth1.$id up
...
= 8< =
= 8< =
$ cat haproxy.cfg
frontend clients
bind 127.0.0.1:50022 namespace 1 transparent
default_backend scb
backend server
mode tcp
server server1 192.168.122.4:2222 namespace 2 send-proxy-v2
= 8< =
A bind line creates the listener in the specified namespace, and connections
originating from that listener also have their network namespace set to
that of the listener.
A server line either forces the connection to be made in a specified
namespace or may use the namespace from the client-side connection if that
was set.
For more documentation please read the documentation included in the patch
itself.
Signed-off-by: KOVACS Tamas <ktamas@balabit.com>
Signed-off-by: Sarkozi Laszlo <laszlo.sarkozi@balabit.com>
Signed-off-by: KOVACS Krisztian <hidden@balabit.com>
Lasse Birnbaum Jensen reported an issue when agent checks are used at the same
time as standard healthchecks when SSL is enabled on the server side.
The symptom is that agent checks try to communicate in SSL while it should
manage raw data. This happens because the transport layer is shared between all
kind of checks.
To fix the issue, the transport layer is now stored in each check type,
allowing to use SSL healthchecks when required, while an agent check should
always use the raw_sock implementation.
The fix must be backported to 1.5.
This patch adds support for a new "drain" mode. So now we have 3 admin
modes for a server :
- READY
- DRAIN
- MAINT
The drain mode disables load balancing but leaves the server up. It can
coexist with maint, except that maint has precedence. It is also inherited
from tracked servers, so just like maint, it's represented with 2 bits.
New functions were designed to set/clear each flag and to propagate the
changes to tracking servers when relevant, and to log the changes. Existing
functions srv_set_adm_maint() and srv_set_adm_ready() were replaced to make
use of the new functions.
Currently the drain mode is not yet used, however the whole logic was tested
with all combinations of set/clear of both flags in various orders to catch
all corner cases.
