Patref:set(key, val[, force]) takes optional "force" parameter (defaults
to false) to force the entry to be created if it doesn't already exist
To retrieve the value, lua_tointeger() was used in place of
lua_toboolean(), and because of that force is not enabled if "true"
is passed as parameter (only numbers were recognized) despite the
documentation mentioning that "force" is a boolean.
To fix the issue, we replace lua_tointeger by lua_toboolean.
Also, the doc was updated to rename "bool" to "boolean" for the "force"
parameter to stay consistent with historical naming in the file.
No backport needed unless 9ee37de5c ("MINOR: hlua_fcn: add Patref:set()")
is.
Patref:set() can achieve the same thing as core.set_map()
Patref:add() can achieve the same thing as core.add_acl()
Patref:del() can achieve the same thing as core.del_map() and
core.del_acl()
As a bonus, Patref:{set,add} are more efficient than their core
legacy equivalent, because they don't require systematic pattern
reference lookup for each individual operation.
Let's mention that in the doc to encourage Patref methods adoption.
Just like we did for server events, in this patch we expose the PAT_REF
event family (see "MINOR: event_hdl: add PAT_REF events") in Lua.
Unlike server events, Patref events don't provide additional event data,
and the registration can only take place from a Patref object (ie: not
globally).
Thanks to this commit it now becomes possible to trigger actions when
updates are performed on a map (or acl list) being monitor, without
the need to loop or use inefficient workarounds.
There is no cli equivalent for this one. It is similar to Patref:add()
excepts thay it takes a table as parameter (for acl: table of keys, for
maps: table of keys:values). The goal is to add multiple entries at once
to limit locking time to the strict minimum. It is recommended to use this
one over Patref:add() when adding multiple entries at once.
Just like "set map" on the cli, the Patref:set() method (only relevant
for maps) can be used to modify an existing entry's value in the pattern
reference pointed to by the Lua Patref object. Lookup is performed on the
key. The update will target the live pattern reference version, unless
Patref:prepare() is ongoing.
Just like "del map" and "del acl" on the cli, the Patref:del() method can
be used to delete an existing entry in the pattern reference pointed to
by the Lua Patref object. The update will target the live pattern
reference version, unless Patref:prepare() is ongoing.
Just like "add map" and "add acl" on the cli, the Patref:add() method can
be used to add a new entry to the pattern reference pointed to by the
Lua Patref object. The update will target the live pattern reference
version, unless Patref:prepare() is ongoing.
If Patref:commit() was used and the new version (generation) isn't going
to be committed, calling Patref:giveup() will allow allocated resources
to be freed and reused. It is a good habit to call this if commit()
isn't called after a prepare().
It is a special Lua Patref method: it bypasses the commit/prepare logic
and purges the whole pattern reference items pointed to by Patref Lua
object (all versions, not just the current one). It doesn't have a cli
equivalent: it leverages pat_ref_purge_range().
Just like the "prepare map" or "prepare acl" on the cli, but for Lua:
it leverages the pattern API to create a subset (ie: a new generation id)
that will automatically be used as target for following Patref operations
(add/set/del...) until the "commit" method is invoked to atomically push
the pending updates.
commit() method may be used to commit pending updates on the local patref
object:
hlua_patref flags were added:
HLUA_PATREF_FL_GEN means the patref object has been updated
and it is associated to a new revision (curr_gen) in order to prepare
and commit the pending updates.
upon commit, the pattern API is leveraged with curr_gen as revision to
commit new object items. Once commit is performed, previous (pending)
revisions that are older than the committed one are cleaned up (similar
to what's done with commit on the cli). Also, Patref function APIs now
take into account curr_gen to perform lookups.
patref object may now leverage index and pair methamethods to list and
access patref elements at a specific index (=key)
Also, patref:is_map() method may be used to know if the patref stores acl
(key only) or map-style (key:value) patterns.
core.get_patref() method may be used to get a reference to a pattern
object (pat_ref struct which is used for maps and acl storage) from
Lua by providing the reference name (filename for files, or prefix+name
for opt or virtual pattern references).
Lua documentation was updated.
Contrary to what the doc states, it is not expected (nor relevant) to
use yield-dependent methods such as core.yield() or core.(m)sleep() from
contexts that don't support yielding. Such contexts include body, init,
fetches and converters.
Thus the doc got it wrong since the beginning, because such methods were
never supported from the above contexts, yet it was listed in the list
of compatible contexts (probably the result of a copy-paste), which is
error-prone because it could either cause a Lua runtime error to be
thrown, or be ignored in some other cases.
It should be backported to all stable versions.
Using CertCache.set() from init context wasn't explicitly supported and
caused the process to crash:
crash.lua:
core.register_init(function()
CertCache.set{filename="reg-tests/ssl/set_cafile_client.pem", ocsp=""}
end)
crash.conf:
global
lua-load crash.lua
listen front
bind localhost:9090 ssl crt reg-tests/ssl/set_cafile_client.pem ca-file reg-tests/ssl/set_cafile_interCA1.crt verify none
./haproxy -f crash.conf
[NOTICE] (267993) : haproxy version is 3.0-dev2-640ff6-910
[NOTICE] (267993) : path to executable is ./haproxy
[WARNING] (267993) : config : missing timeouts for proxy 'front'.
| While not properly invalid, you will certainly encounter various problems
| with such a configuration. To fix this, please ensure that all following
| timeouts are set to a non-zero value: 'client', 'connect', 'server'.
[1] 267993 segmentation fault (core dumped) ./haproxy -f crash.conf
This is because in hlua_ckch_set/hlua_ckch_commit_yield, we always
consider that we're being called from a yield-capable runtime context.
As such, hlua_gethlua() is never checked for NULL and we systematically
try to wake hlua->task and yield every 10 instances.
In fact, if we're called from the body or init context (that is, during
haproxy startup), hlua_gethlua() will return NULL, and in this case we
shouldn't care about yielding because it is ok to commit all instances
at once since haproxy is still starting up.
Also, when calling CertCache.set() from a non-yield capable runtime
context (such as hlua fetch context), we kept doing as if the yield
succeeded, resulting in unexpected function termination (operation
would be aborted and the CertCache lock wouldn't be released). Instead,
now we explicitly state in the doc that CertCache.set() cannot be used
from a non-yield capable runtime context, and we raise a runtime error
if it is used that way.
These bugs were discovered by reading the code when trying to address
Svace report documented by @Bbulatov GH #2586.
It should be backported up to 2.6 with 30fcca18 ("MINOR: ssl/lua:
CertCache.set() allows to update an SSL certificate file")
At the beginning of the filter class section, we encourage the user to
check out filters.txt file to get to know how the filters API works
within haproxy.
However the file location is incorrect. The proper directory to look for
the file is: doc/internals/api.
It should be backported up to 2.5.
Add core.silent (-1) value to be able to disable logging via
TXN:set_loglevel() call. Otherwise, there is no way to do so and it may be
handy. This special value cannot be used with TXN:log() function.
This patch may be backported if necessary.
This is a complementary patch to "MINOR: tcp-act: Rename "set-{mark,tos}"
to "set-fc-{mark,tos}"", but for the Lua API.
set_mark and set_tos were kept as aliases for set_fc_mark and set_fc_tos
but they were marked as deprecated.
Using this opportunity to reorder set_mark and set_tos by alphabetical
order.
Because maps and list of ACLs are no longer necessarily referenced by
filenames, CLI commands to manipulate them were updated accordingly. Instead
of "filename" we talk about "name" now.
The same is performed in the LUA documentation.
Following previous commit: in this patch we add the "syslog" output as
possible return value for Proxy.get_mode() function since log backend
may now be enumerated from lua with 9a74a6c ("MAJOR: log: introduce log
backends")
Proxy.get_mode() function internally relies on proxy_mode_str() to return
the proxy mode. The current function description is exhaustive about the
possible outputs for the function. I can't tell if it's relevant or not
but it's subject to changes. Here it is the case, the documentation
indicates that "health" mode may be returned, which cannot happen
since 77e0daef9 ("MEDIUM: proxy: remove obsolete "mode health"").
This should be backported up to 2.4
After making it configurable in previous commit "MINOR: lua: Add flags
to configure logging behaviour", this patch changes the default value
of tune.lua.log.stderr from 'on' (unconditionally forward LUA logs to
stderr) to 'auto' (only forward LUA logs to stderr if logging via a
standard logger is disabled, or none is configured for the current context)
Since this is a change in behaviour, it shouldn't be backported
Until now, messages printed from LUA log functions were sent both to
the any logger configured for the current proxy, and additionally to
stderr (in most cases)
This introduces two flags to configure LUA log handling:
- tune.lua.log.loggers to use standard loggers or not
- tune.lua.log.stderr to use stderr, or not, or only conditionally
This addresses github feature request #2316
This can be backported to 2.8 as it doesn't change previous behaviour.
This commit introduces support for the "http-after-res" action in
hlua, enabling the invocation of a Lua function in a
"http-after-response" rule. With this enhancement, a Lua action can be
registered using the "http-after-res" action type:
core.register_action('myaction', {'http-after-res'}, myaction)
A new "lua.myaction" is created and can be invoked in a
"http-after-response" rule:
http-after-response lua.myaction
This addition provides greater flexibility and extensibility in
handling post-response actions using Lua.
This commit depends on:
- 4457783 ("MINOR: http_ana: position the FINAL flag for http_after_res execution")
Signed-off-by: Sébastien Gross <sgross@haproxy.com>
"converter" was used in place of "action" as a result of a copy-paste
error probably.
Also, rephrasing the "actions" keyword explanation to prevent confusion
between action name (which is the name of new action about to be created)
and action facilities where we want to expose the new action.
This could be backported to every stable versions.
Since f034139bc0 ("MINOR: lua: Allow reading "proc." scoped vars from
LUA core."), a new Sphinx warning is emitted when generating the lua doc:
"WARNING: Field list ends without a blank line; unexpected unindent."
This is due to a missing space after the line break continuation, sphinx
parser is very restrictive unfortunately!
Suppressing the warning and fixing the html output at the same time by
adding the missing space.
This adds the "core.get_var()" method allow the reading
of "proc." scoped variables outside of TXN or HTTP/TCPApplet.
Fixes: #2212
Signed-off-by: Daan van Gorkum <djvg@djvg.net>
As the example/lua/mailers.lua script does its best to mimic the c-mailer
implementation, it should support the "timeout mail" directive as well.
This could be backported in 2.8.
Despite the doc not mentionning it, core.{proxies,frontends,backends}
methods are also available from init context.
(through core.register_init() functions)
Updating the documentation to reflect this possibility.
Adding a new lua class: Queue.
This class provides a generic FIFO storage mechanism that may be shared
between multiple lua contexts to easily pass data between them, as stock
Lua doesn't provide easy methods for passing data between multiple
coroutines.
New Queue object may be obtained using core.queue()
(it works like core.concat() for a concat Class)
Lua documentation was updated (including some usage examples)
Proxy mailers, which are configured using "email-alert" directives
in proxy sections from the configuration, are now being exposed
directly in lua thanks to the proxy:get_mailers() method which
returns a class containing the various mailers settings if email
alerts are configured for the given proxy (else nil is returned).
Both the class and the proxy method were marked as LEGACY since this
feature relies on mailers configuration, and the goal here is to provide
the last missing bits of information to lua scripts in order to make
them capable of sending email alerts instead of relying on the soon-to-
be deprecated mailers implementation based on checks (see src/mailers.c)
Lua documentation was updated accordingly.
Exposing a new hlua function, available from body or init contexts, that
forcefully disables the sending of email alerts even if the mailers are
defined in haproxy configuration.
This will help for sending email directly from lua.
(prevent legacy email sending from intefering with lua)
Exposing SERVER_CHECK event through the lua API.
New lua class named ServerEventCheck was added to provide additional
data for SERVER_CHECK event.
Lua documentation was updated accordingly.
Server.get_pend_conn: number of pending connections to the server
Server.get_cur_sess: number of current sessions handled by the server
Lua documentation was updated accordingly.
'when' optional argument is provided to lua event handlers.
It is an integer representing the number of seconds elapsed since Epoch
and may be used in conjunction with lua `os.date()` function to provide
a custom format string.
Now that event_hdl api is properly implemented in hlua, we may add the
per-server event subscription in addition to the global event
subscription.
Per-server subscription allows to be notified for events related to
single server. It is useful to track a server UP/DOWN and DEL events.
It works exactly like core.event_sub() except that the subscription
will be performed within the server dedicated subscription list instead
of the global one.
The callback function will only be called for server events affecting
the server from which the subscription was performed.
Regarding the implementation, it is pretty trivial at this point, we add
more doc than code this time.
Usage examples have been added to the (lua) documentation.
Now that the event handler API is pretty mature, we can expose it in
the lua API.
Introducing the core.event_sub(<event_types>, <cb>) lua function that
takes an array of event types <event_types> as well as a callback
function <cb> as argument.
The function returns a subscription <sub> on success.
Subscription <sub> allows you to manage the subscription from anywhere
in the script.
To this day only the sub->unsub method is implemented.
The following event types are currently supported:
- "SERVER_ADD": when a server is added
- "SERVER_DEL": when a server is removed from haproxy
- "SERVER_DOWN": server states goes from up to down
- "SERVER_UP": server states goes from down to up
As for the <cb> function: it will be called when one of the registered
event types occur. The function will be called with 3 arguments:
cb(<event>,<data>,<sub>)
<event>: event type (string) that triggered the function.
(could be any of the types used in <event_types> when registering
the subscription)
<data>: data associated with the event (specific to each event family).
For "SERVER_" family events, server details such as server name/id/proxy
will be provided.
If the server still exists (not yet deleted), a reference to the live
server is provided to spare you from an additionnal lookup if you need
to have direct access to the server from lua.
<sub> refers to the subscription. In case you need to manage it from
within an event handler.
(It refers to the same subscription that the one returned from
core.event_sub())
Subscriptions are per-thread: the thread that will be handling the
event is the one who performed the subscription using
core.event_sub() function.
Each thread treats events sequentially, it means that if you have,
let's say SERVER_UP, then SERVER_DOWN in a short timelapse, then your
cb function will first be called with SERVER_UP, and once you're done
handling the event, your function will be called again with SERVER_DOWN.
This is to ensure event consitency when it comes to logging / triggering
logic from lua.
Your lua cb function may yield if needed, but you're pleased to process
the event as fast as possible to prevent the event queue from growing up
To prevent abuses, if the event queue for the current subscription goes
over 100 unconsumed events, the subscription will pause itself
automatically for as long as it takes for your handler to catch up.
This would lead to events being missed, so a warning will be emitted in
the logs to inform you about that. This is not something you want to let
happen too often, it may indicate that you subscribed to an event that
is occurring too frequently or/and that your callback function is too
slow to keep up the pace and you should review it.
If you want to do some parallel processing because your callback
functions are slow: you might want to create subtasks from lua using
core.register_task() from within your callback function to perform the
heavy job in a dedicated task and allow remaining events to be processed
more quickly.
Please check the lua documentation for more information.
