It is now possible to intercept HTTP messages from a lua action and reply to
clients. To do so, a reply object must be provided to the function
txn:done(). It may contain a status code with a reason, a header list and a
body. By default, if an empty reply object is used, an empty 200 response is
returned. If no reply is passed when txn:done() is called, the previous
behaviour is respected, the transaction is terminated and nothing is returned to
the client. The same is done for TCP streams. When txn:done() is called, the
action is terminated with the code ACT_RET_DONE on success and ACT_RET_ERR on
error, interrupting the message analysis.
The reply object may be created for the lua, by hand. Or txn:reply() may be
called. If so, this object provides some methods to fill it:
* Reply:set_status(<status> [ <reason>]) : Set the status and optionally the
reason. If no reason is provided, the default one corresponding to the status
code is used.
* Reply:add_header(<name>, <value>) : Add a header. For a given name, the
values are stored in an ordered list.
* Reply:del_header(<name>) : Removes all occurrences of a header name.
* Reply:set_body(<body>) : Set the reply body.
Here are some examples, all doing the same:
-- ex. 1
txn:done{
status = 400,
reason = "Bad request",
headers = {
["content-type"] = { "text/html" },
["cache-control"] = { "no-cache", "no-store" },
},
body = "<html><body><h1>invalid request<h1></body></html>"
}
-- ex. 2
local reply = txn:reply{
status = 400,
reason = "Bad request",
headers = {
["content-type"] = { "text/html" },
["cache-control"] = { "no-cache", "no-store" }
},
body = "<html><body><h1>invalid request<h1></body></html>"
}
txn:done(reply)
-- ex. 3
local reply = txn:reply()
reply:set_status(400, "Bad request")
reply:add_header("content-length", "text/html")
reply:add_header("cache-control", "no-cache")
reply:add_header("cache-control", "no-store")
reply:set_body("<html><body><h1>invalid request<h1></body></html>")
txn:done(reply)
This function may be used to defined a timeout when a lua action returns
act:YIELD. It is a way to force to reexecute the script after a short time
(defined in milliseconds).
Unlike core:sleep() or core:yield(), the script is fully reexecuted if it
returns act:YIELD. With core functions to yield, the script is interrupted and
restarts from the yield point. When a script returns act:YIELD, it is finished
but the message analysis is blocked on the action waiting its end.
ACT_RET_* code are now available from lua scripts. The gloabl object "act" is
used to register these codes as constant. Now, lua actions can return any of
following codes :
* act.CONTINUE for ACT_RET_CONT
* act.STOP for ACT_RET_STOP
* act.YIELD for ACT_RET_YIELD
* act.ERROR for ACT_RET_ERR
* act.DONE for ACT_RET_DONE
* act.DENY for ACT_RET_DENY
* act.ABORT for ACT_RET_ABRT
* act.INVALID for ACT_RET_INV
For instance, following script denied all requests :
core.register_action("deny", { "http-req" }, function (txn)
return act.DENY
end)
Thus "http-request lua.deny" do exactly the same than "http-request deny".
This ads support for accessing stick tables from Lua. The supported
operations are reading general table info, lookup by string/IP key, and
dumping the table.
Similar to "show table", a data filter is available during dump, and as
an improvement over "show table" it's possible to use up to 4 filter
expressions instead of just one (with implicit AND clause binding the
expressions). Dumping with/without filters can take a long time for
large tables, and should be used sparingly.
This adds the set-priority-class and set-priority-offset actions to
http-request and tcp-request content. At this point they are not used
yet, which is the purpose of the next commit, but all the logic to
set and clear the values is there.
* A few typos
* Fix definitions of values which are tables, not arrays.
* Consistent US English naming for "server" instead of "serveur".
[tfo: should be backported to 1.6 and higher]
Instead of hlua_socket_settimeout() accepting only integers, allow user
to specify float and double as well. Convert to milliseconds much like
cli_parse_set_timeout but also sanity check the value.
http://w3.impa.br/~diego/software/luasocket/tcp.html#settimeout
T. Fournier edit:
The main goal is to keep compatibility with the LuaSocket API. This
API only accept seconds, so using a float to specify milliseconds is
an acceptable way.
Update doc.
The `socket.tcp.connect` method of Lua requires at least two parameters:
The host and the port. The `Socket.connect` method of haproxy requires
only one when a host with a combined port is provided. This stems from
the fact that `str2sa_range` is used internally in `hlua_socket_connect`.
This very fact unfortunately causes a diversion in the behaviour of
Lua's socket class and haproxy's for IPv6 addresses:
sock:connect("::1", "80")
works fine with Lua, but fails with:
connect: cannot parse destination address '::1'
in haproxy, because `str2sa_range` parses the trailing `:1` as the port.
This patch forcefully adds a `:` to the end of the address iff a port
number greater than `0` is given as the second parameter.
Technically this breaks backwards compatibility, because the docs state:
> The syntax "127.0.0.1:1234" is valid. in this case, the
> parameter *port* is ignored.
But: The connect() call can only succeed if the second parameter is left
out (which causes no breakage) or if the second parameter is an integer
or a numeric string.
It seems unlikely that someone would provide an address with a port number
and would also provide a second parameter containing a number other than
zero. Thus I feel this breakage is warranted to fix the mismatch between
haproxy's socket class and Lua's one.
This commit should be backported to haproxy 1.8 only, because of the
possible breakage of existing Lua scripts.
This patch simply brings HAProxy internal regex system to the Lua API.
Lua doesn't embed regexes, now it inherits from the regexes compiled
with haproxy.
Adis Nezirovic reports:
While playing with Lua API I've noticed that core.proxies attribute
doesn't return all the proxies, more precisely the ones with same names
(e.g. for frontend and backend with the same name it would only return
the latter one).
So, this patch fixes this problem without breaking the actual behaviour.
We have two case of proxies with frontend/backend capabilities:
The first case is the listen. This case is not a problem because the
proxy object process these two entities as only one and it is the
expected behavior. With these case the "proxies" list works fine.
The second case is the frontend and backend with the same name. i think
that this case is possible for compatibility with 'listen' declaration.
These two proxes with same name and different capabilities must not
processed with the same object (different statitics, differents orders).
In fact, one the the two object crush the other one whoch is no longer
accessible.
To fix this problem, this patch adds two lists which are "frontends" and
"backends", each of these list contains specialized proxy, but warning
the "listen" proxy are declare in each list.
This patch change the names prefixing it by a "_". So "end" becomes "_end".
The backward compatibility with names without the prefix "_" is assured.
In other way, another the keyword "end" can be used like this: Map['end'].
Thanks Robin H. Johnson for the bug repport
This should be backported in version 1.6 and 1.7
The older 'rsprep' directive allows modification of the status reason.
Extend 'http-response set-status' to take an optional string of the new
status reason.
http-response set-status 418 reason "I'm a coffeepot"
Matching updates in Lua code:
- AppletHTTP.set_status
- HTTP.res_set_status
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
The parameter "value" of the function TXN.set_var() was not documented.
This is a regression from the commit 85d79c94a9.
This patch must be backported in 1.7
For tokenizing a string, standard Lua recommends to use regexes.
The followinf example splits words:
for i in string.gmatch(example, "%S+") do
print(i)
end
This is a little bit overkill for simply split words. This patch
adds a tokenize function which quick and do not use regexes.
It does the opposite of 'set-var' action/converter. It is really useful for
per-process variables. But, it can be used for any scope.
The lua function 'unset_var' has also been added.
The functions "req_replace_value()" and "res_replace_value()"
doesn't exists in the 1.6 version. There inherited from the 1.6dev.
This patch must be backported in 1.6 version
The function txn_done() ends a transaction. It does not make
sense to call this function from a lua sample-fetch wrapper,
because the role of a sample-fetch is not to terminate a
transaction.
This patch modify the role of the fucntion txn_done() if it
is called from a sample-fetch wrapper, now it just ends the
execution of the Lua code like the done() function.
Must be backported in 1.6
The applet can't have access to the session private data. This patch
fix this problem. Now an applet can use private data stored by actions
and fecthes.
This patch fix the Lua API documentation, and adds some internal link
between values returned and associated class.
This patch can be backported in 1.6.
When a POST is processed by a Lua service, the HTTP header are
potentially gone. So, we cannot retrieve their content using
the standard "hdr" sample fetchs (which will soon become invalid
anyway) from an applet.
This patch add an entry "headers" to the object applet_http. This
entry is an array containing all the headers. It permits to use the
HTTP headers during the processing of the service.
Many thanks to Jan Bruder for reporting this issue with enough
details to reproduce it.
This patch will have to be backported to 1.6 since it will be the
only way to access headers from Lua applets.
The current Lua action are not registered. The executed function is
selected according with a function name writed in the HAProxy configuration.
This patch add an action registration function. The configuration mode
described above disappear.
This change make some incompatibilities with existing configuration files for
HAProxy 1.6-dev.
