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src | ||
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util | ||
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README.markdown | ||
config | ||
valgrind.suppress |
README.markdown
Name
ngx_lua - Embed the Power of Lua into Nginx
Status
This module is still under active development but is already production ready :)
Commit bit can be freely delivered at your request ;)
Synopsis
# set search paths for pure Lua external libraries (';;' is the default path):
lua_package_path '/foo/bar/?.lua;/blah/?.lua;;';
# set search paths for Lua external libraries written in C (can also use ';;'):
lua_package_cpath '/bar/baz/?.so;/blah/blah/?.so;;';
server {
location /inline_concat {
# MIME type determined by default_type:
default_type 'text/plain';
set $a "hello";
set $b "world";
# inline lua script
set_by_lua $res "return ngx.arg[1]..ngx.arg[2]" $a $b;
echo $res;
}
location /rel_file_concat {
set $a "foo";
set $b "bar";
# script path relative to nginx prefix
# $ngx_prefix/conf/concat.lua contents:
#
# return ngx.arg[1]..ngx.arg[2]
#
set_by_lua_file $res conf/concat.lua $a $b;
echo $res;
}
location /abs_file_concat {
set $a "fee";
set $b "baz";
# absolute script path not modified
set_by_lua_file $res /usr/nginx/conf/concat.lua $a $b;
echo $res;
}
location /lua_content {
# MIME type determined by default_type:
default_type 'text/plain';
content_by_lua "ngx.say('Hello,world!')"
}
location /nginx_var {
# MIME type determined by default_type:
default_type 'text/plain';
# try access /nginx_var?a=hello,world
content_by_lua "ngx.print(ngx.var['arg_a'], '\\n')";
}
location /request_body {
# force reading request body (default off)
lua_need_request_body on;
content_by_lua 'ngx.print(ngx.var.request_body)';
}
# transparent non-blocking I/O in Lua via subrequests
location /lua {
# MIME type determined by default_type:
default_type 'text/plain';
content_by_lua '
local res = ngx.location.capture("/some_other_location")
if res.status == 200 then
ngx.print(res.body)
end';
}
# GET /recur?num=5
location /recur {
# MIME type determined by default_type:
default_type 'text/plain';
content_by_lua '
local num = tonumber(ngx.var.arg_num) or 0
ngx.say("num is: ", num)
if num > 0 then
res = ngx.location.capture("/recur?num=" .. tostring(num - 1))
ngx.print("status=", res.status, " ")
ngx.print("body=", res.body)
else
ngx.say("end")
end
';
}
location /foo {
rewrite_by_lua '
res = ngx.location.capture("/memc",
{ args = { cmd = 'incr', key = ngx.var.uri } }
)
';
proxy_pass http://blah.blah.com;
}
location /blah {
access_by_lua '
local res = ngx.location.capture("/auth")
if res.status == ngx.HTTP_OK then
return
end
if res.status == ngx.HTTP_FORBIDDEN then
ngx.exit(res.status)
end
ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
';
# proxy_pass/fastcgi_pass/postgres_pass/...
}
location /mixed {
rewrite_by_lua_file /path/to/rewrite.lua;
access_by_lua_file /path/to/access.lua;
content_by_lua_file /path/to/content.lua;
}
# use nginx var in code path
# WARN: contents in nginx var must be carefully filtered,
# otherwise there'll be great security risk!
location ~ ^/app/(.+) {
content_by_lua_file /path/to/lua/app/root/$1.lua;
}
location / {
lua_need_request_body on;
client_max_body_size 100k;
client_body_buffer_size 100k;
access_by_lua '
-- check the client IP addr is in our black list
if ngx.var.remote_addr == "132.5.72.3" then
ngx.exit(ngx.HTTP_FORBIDDEN)
end
-- check if the request body contains bad words
if ngx.var.request_body and
string.match(ngx.var.request_body, "fsck")
then
return ngx.redirect("/terms_of_use.html")
end
-- tests passed
';
# proxy_pass/fastcgi_pass/etc settings
}
}
Description
This module embeds the Lua interpreter into the nginx core and integrates the powerful Lua threads (aka Lua coroutines) into the nginx event model by means of nginx subrequests.
Unlike Apache's mod_lua and Lighttpd's mod_magnet, Lua code written atop this module can be 100% non-blocking on network traffic
as long as you use the ngx.location.capture
interface
to let the nginx core do all your
requests to mysql, postgresql, memcached,
upstream http web services, and etc etc etc (see
ngx_drizzle, ngx_postgres, ngx_memc, and ngx_proxy modules for details).
The Lua interpreter instance is shared across all the requests in a single nginx worker process.
Request contexts are isolated from each other by means of Lua (lightweight) threads (aka Lua coroutines). And Lua modules loaded are persistent on the nginx worker process level. So the memory footprint is quite small even when your nginx worker process is handling 10K requests at the same time.
We're already using this module very heavily in our production web applications here in Taobao.com, Alibaba Group.
Directives
lua_package_path
- Syntax:
lua_package_path <lua-style-path-str>
- Default: The content of LUA_PATH environ variable or Lua's compiled-in defaults.
- Context:
main
Set the Lua module searching path used by scripts specified by set_by_lua*
,
content_by_lua*
and others. The path string is in standard Lua path form, and ;;
can be used to stand for the original path.
lua_package_cpath
- Syntax:
lua_package_cpath <lua-style-cpath-str>
- Default: The content of LUA_CPATH environ variable or Lua's compiled-in defaults.
- Context:
main
Set the Lua C-module searching path used by scripts specified by set_by_lua*
,
content_by_lua*
and others. The cpath string is in standard Lua cpath form, and ;;
can be used to stand for the original cpath.
set_by_lua
- Syntax:
set_by_lua $res <lua-script-str> [$arg1 $arg2 ...]
- Context:
main | server | location | sif | lif
Execute user code specified by <lua-script-str>
with input arguments $arg1 $arg2 ...
, and set the script's return value to $res
in string form. In
<lua-script-str>
code the input arguments can be retrieved from ngx.arg
table (index starts from 1
and increased sequentially).
set_by_lua*
directives are designed to execute small and quick codes. Nginx
event loop is blocked during the code execution, so you'd better NOT call
anything that may be blocked or time-costy.
Note that set_by_lua
can only output a value to a single nginx variable at
a time. But a work-around is also available by means of the ngx.var.xxx interface,
for example,
location /foo {
set $diff ''; # we have to predefine the $diff variable here
set_by_lua $sum '
local a = 32
local b = 56
ngx.var.diff = a - b; -- write to $diff directly
return a + b; -- return the $sum value normally
';
echo "sum = $sum, diff = $diff";
}
set_by_lua_file
- Syntax:
set_by_lua_file $res <path-to-lua-script> [$arg1 $arg2 ...]
- Context:
main | server | location | sif | lif
Basically the same as set_by_lua
, except the code to be executed is in the
file specified by <path-lua-script>
.
The user code is loaded once at the first request and cached. Nginx config must be reloaded if you modified the file and expected to see updated behavior.
content_by_lua
- Syntax:
content_by_lua <lua-script-str>
- Context:
location | lif
- Phase:
content
Act as a content handler and execute user code specified by <lua-script-str>
for every request. The user code may call predefined APIs to generate response
content.
The use code is executed in a new spawned coroutine with independent globals environment (i.e. a sandbox). I/O operations in user code should only be done through predefined Nginx APIs, otherwise Nginx event loop may be blocked and performance may drop off dramatically.
As predefined Nginx I/O APIs used coroutine yielding/resuming mechanism, the
user code should not call any modules that used coroutine API to prevent
obfuscating the predefined Nginx APIs (actually coroutine module is masked off
in content_by_lua*
directives). This limitation is a little crucial, but
don't worry! We're working on a alternative coroutine implementation that can
be fit in the Nginx event framework. When it is done, the user code will be
able to use coroutine mechanism freely as in standard Lua again!
rewrite_by_lua
- Syntax:
rewrite_by_lua <lua-script-str>
- Context:
location | lif
- Phase:
rewrite tail
Act as a rewrite phase handler and execute user code specified by <lua-script-str>
for every request. The user code may call predefined APIs to generate response
content.
This hook uses exactly the same mechamism as content_by_lua
so all the nginx APIs defined there
are also available here.
Note that this handler always runs after the standard nginx rewrite module ( http://wiki.nginx.org/NginxHttpRewriteModule ). So the following will work as expected:
location /foo { set $a 12; # create and initialize $a set $b ''; # create and initialize $b rewrite_by_lua 'ngx.var.b = tonumber(ngx.var.a) + 1'; echo "res = $b"; }
because set $a 12
and set $b ''
run before rewrite_by_lua
.
On the other hand, the following will not work as expected:
? location /foo {
? set $a 12; # create and initialize $a
? set $b ''; # create and initialize $b
? rewrite_by_lua 'ngx.var.b = tonumber(ngx.var.a) + 1';
? if ($b = '13') {
? rewrite ^ /bar redirect;
? break;
? }
?
? echo "res = $b";
? }
because if
runs before rewrite_by_lua
even if it's put after rewrite_by_lua
in the config.
The right way of doing this is as follows:
location /foo {
set $a 12; # create and initialize $a
set $b ''; # create and initialize $b
rewrite_by_lua '
ngx.var.b = tonumber(ngx.var.a) + 1
if ngx.var.b == 13 then
return ngx.redirect("/bar");
end
';
echo "res = $b";
}
It's worth mentioning that, the ngx_eval
module can be
approximately implemented by rewrite_by_lua
. For example,
location / {
eval $res {
proxy_pass http://foo.com/check-spam;
}
if ($res = 'spam') {
rewrite ^ /terms-of-use.html redirect;
}
fastcgi_pass ...;
}
can be implemented in terms of ngx_lua
like this
location = /check-spam {
internal;
proxy_pass http://foo.com/check-spam;
}
location / {
rewrite_by_lua '
local res = ngx.location.capture("/check-spam")
if res.body == "spam" then
ngx.redirect("/terms-of-use.html")
end
';
fastcgi_pass ...;
}
Just as any other rewrite-phase handlers, rewrite_by_lua
also runs in subrequests.
Note that calling ngx.exit(ngx.OK)
just returning from the current rewrite_by_lua
handler, and the nginx request processing
control flow will still continue to the content handler. To terminate the current request from within the current rewrite_by_lua
handler,
calling ngx.exit(ngx.HTTP_OK)
for successful quits and ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
or its friends for failures.
This directive won't work properly with nginx 0.7.x.
access_by_lua
- Syntax:
access_by_lua <lua-script-str>
- Context:
location | lif
- Phase:
access tail
Act as an access phase handler and execute user code specified by <lua-script-str>
for every request. The user code may call predefined APIs to generate response
content.
This hook uses exactly the same mechamism as content_by_lua
so all the nginx APIs defined there
are also available here.
Note that this handler always runs after the standard nginx access module ( http://wiki.nginx.org/NginxHttpAccessModule ). So the following will work as expected:
location / {
deny 192.168.1.1;
allow 192.168.1.0/24;
allow 10.1.1.0/16;
deny all;
access_by_lua '
local res = ngx.location.capture("/mysql", { ... })
...
';
# proxy_pass/fastcgi_pass/...
}
That is, if a client address appears in the blacklist, then
we don't have to bother sending a mysql query to do more
advanced authentication in access_by_lua
.
It's worth mentioning that, the ngx_auth_request
module can be
approximately implemented by access_by_lua
. For example,
location / {
auth_request /auth;
# proxy_pass/fastcgi_pass/postgres_pass/...
}
can be implemented in terms of ngx_lua
like this
location / {
access_by_lua '
local res = ngx.location.capture("/auth")
if res.status == ngx.HTTP_OK then
return
end
if res.status == ngx.HTTP_FORBIDDEN then
ngx.exit(res.status)
end
ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
';
# proxy_pass/fastcgi_pass/postgres_pass/...
}
Just as any other access-phase handlers, access_by_lua
will NOT run in subrequests.
Note that calling ngx.exit(ngx.OK)
just returning from the current access_by_lua
handler, and the nginx request processing
control flow will still continue to the content handler. To terminate the current request from within the current access_by_lua
handler,
calling ngx.exit(ngx.HTTP_OK)
for successful quits and ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
or its friends for failures.
content_by_lua_file
- Syntax:
content_by_lua_file <path-to-lua-script>
- Context:
location | lif
- Phase:
content
Basically the same as content_by_lua
, except the code to be executed is in
the file specified by <path-lua-script>
.
The user code is loaded once at the first request and cached. Nginx config must be reloaded if you modified the file and expected to see updated behavior.
Nginx variables can be used in string, in order to provide greater flexibility in practice. But this feature must be used carefully, so is not recommend for beginners.
rewrite_by_lua_file
- Syntax:
rewrite_by_lua_file <path-to-lua-script>
- Context:
location | lif
- Phase:
rewrite tail
Same as rewrite_by_lua
, except the code to be executed is in
the file specified by <path-lua-script>
.
This directive won't work properly with nginx 0.7.x.
Nginx variables can be used in string, in order to provide greater flexibility in practice. But this feature must be used carefully, so is not recommend for beginners.
access_by_lua_file
- Syntax:
access_by_lua_file <path-to-lua-script>
- Context:
location | lif
- Phase:
access tail
Same as access_by_lua
, except the code to be executed is in the file
specified by <path-lua-script>
.
Nginx variables can be used in string, in order to provide greater flexibility in practice. But this feature must be used carefully, so is not recommend for beginners.
lua_need_request_body
- Syntax:
lua_need_request_body <on | off>
- Default:
off
- Context:
main | server | location
- Phase:
depends on usage
Force reading request body data or not. The client request body won't be read, so you have to explicitly force reading the body if you need its content.
If you want to read the request body data from the $request_body
variable, make sure that
your client_max_body_size
setting is equal to
your client_body_buffer_size
setting and
the capacity specified should hold the biggest
request body that your app allow.
If the current location defines rewrite_by_lua
or rewrite_by_lua_file
,
then the request body will be read just before the rewrite_by_lua
or rewrite_by_lua_file
code is run (and also at the
rewrite
phase). Similarly, if only content_by_lua
is specified,
the request body won't be read until the content handler's Lua code is
about to run (i.e., the request body will be read at the
content phase).
The same applies to access_by_lua
and access_by_lua_file
.
Nginx API for Lua
Input arguments
- Context:
set_by_lua*
Index the input arguments to the set_by_lua* directives:
value = ngx.arg[n]
Here's an example
location /foo {
set $a 32;
set $b 56;
set_by_lua $res
'return tonumber(ngx.arg[1]) + tonumber(ngx.arg[2])'
$a $b;
echo $sum;
}
that outputs 88, the sum of 32 and 56.
Read and write Nginx variables
-
Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
value = ngx.var.some_nginx_variable_name ngx.var.some_nginx_variable_name = value
Note that you can only write to nginx variables that are already defined. For example:
location /foo {
set $my_var ''; # this line is required to create $my_var at config time
content_by_lua '
ngx.var.my_var = 123;
...
';
}
That is, nginx variables cannot be created on-the-fly.
Core constants
-
Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
ngx.OK ngx.DONE ngx.AGAIN ngx.ERROR
HTTP method constants
-
Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
value = ngx.HTTP_GET value = ngx.HTTP_HEAD value = ngx.HTTP_PUT value = ngx.HTTP_POST value = ngx.HTTP_DELETE
HTTP status constants
-
Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
value = ngx.HTTP_OK value = ngx.HTTP_CREATED value = ngx.HTTP_MOVED_PERMANENTLY value = ngx.HTTP_MOVED_TEMPORARILY value = ngx.HTTP_NOT_MODIFIED value = ngx.HTTP_BAD_REQUEST value = ngx.HTTP_GONE value = ngx.HTTP_NOT_FOUND value = ngx.HTTP_NOT_ALLOWED value = ngx.HTTP_FORBIDDEN value = ngx.HTTP_INTERNAL_SERVER_ERROR value = ngx.HTTP_SERVICE_UNAVAILABLE
Nginx log level constants
-
Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
log_level = ngx.STDERR log_level = ngx.EMERG log_level = ngx.ALERT log_level = ngx.CRIT log_level = ngx.ERR log_level = ngx.WARN log_level = ngx.NOTICE log_level = ngx.INFO log_level = ngx.DEBUG
print(a, b, ...)
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Emit args concatenated to error.log
, with log level ngx.NOTICE
and prefix lua print:
.
It's equivalent to
ngx.log(ngx.NOTICE, 'lua print: ', a, b, ...)
Nil arguments are accepted and result in literal "nil".
ngx.location.capture(uri, options?)
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Issue a synchronous but still non-blocking "nginx subrequest" using uri
.
Nginx subrequests provide a powerful way to make
non-blocking internal requests to other locations
configured with disk file directory or any
other nginx C modules like
ngx_proxy
, ngx_fastcgi
, ngx_memc
,
ngx_postgres
,
ngx_drizzle
, and even ngx_lua
itself and etc etc etc.
Also note that subrequests just mimic the HTTP interface but there's no extra HTTP/TCP traffic nor IPC involved. Everything works internally, efficiently, on the C level.
Subrequests are completely different from HTTP 301/302 redirection (via ngx.redirect()
) and internal redirection (via ngx.exec()
).
Here's a basic example:
res = ngx.location.capture(uri)
Returns a Lua table with three slots (res.status
, res.header
, and res.body
).
res.header
holds all the response headers of the
subrequest and it is a normal Lua table. For multi-value response headers,
the value is a Lua (array) table that holds all the values in the order that
they appear. For instance, if the subrequest response headers contains the following
lines:
Set-Cookie: a=3
Set-Cookie: foo=bar
Set-Cookie: baz=blah
Then res.header["Set-Cookie"]
will be evaluted to the table value
{"a=3", "foo=bar", "baz=blah"}
.
URI query strings can be concatenated to URI itself, for instance,
res = ngx.location.capture('/foo/bar?a=3&b=4')
Named locations like @foo
are not allowed due to a limitation in
the nginx core. Use normal locations combined with the internal
directive to
prepare internal-only locations.
An optional option table can be fed as the second
argument, which support various options like
method
, body
, args
, and share_all_vars
.
Issuing a POST subrequest, for example,
can be done as follows
res = ngx.location.capture(
'/foo/bar',
{ method = ngx.HTTP_POST, body = 'hello, world' }
)
See HTTP method constants methods other than POST.
The method
option is ngx.HTTP_GET
by default.
The share_all_vars
option can control whether to share nginx variables
among the current request and the new subrequest. If this option is set to true
, then
the subrequest can see all the variable values of the current request while the current
requeset can also see any variable value changes made by the subrequest.
Note that variable sharing can have unexpected side-effects
and lead to confusing issues, use it with special
care. So, by default, the option is set to false
.
The args
option can specify extra url arguments, for instance,
ngx.location.capture('/foo?a=1',
{ args = { b = 3, c = ':' } }
)
is equivalent to
ngx.location.capture('/foo?a=1&b=3&c=%3a')
that is, this method will autmotically escape argument keys and values according to URI rules and concatenating them together into a complete query string. Because it's all done in hand-written C, it should be faster than your own Lua code.
The args
option can also take plain query string:
ngx.location.capture('/foo?a=1',
{ args = 'b=3&c=%3a' } }
)
This is functionally identical to the previous examples.
ngx.status
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Read and write the response status. This should be called before sending out the response headers.
ngx.status = ngx.HTTP_CREATED
status = ngx.status
ngx.header.HEADER
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Set/add/clear response headers. Underscores (_) in the header names will be replaced by dashes (-) and the header names will be matched case-insentively.
-- equivalent to ngx.header["Content-Type"] = 'text/plain'
ngx.header.content_type = 'text/plain';
ngx.header["X-My-Header"] = 'blah blah';
Multi-value headers can be set this way:
ngx.header['Set-Cookie'] = {'a=32; path=/', 'b=4; path=/'}
will yield
Set-Cookie: a=32; path=/
Set-Cookie: b=4; path=/
in the response headers. Only array-like tables are accepted.
Note that, for those standard headers that only accepts a single value, like Content-Type, only the last element in the (array) table will take effect. So
ngx.header.content_type = {'a', 'b'}
is equivalent to
ngx.header.content_type = 'b'
Setting a slot to nil effectively removes it from the response headers:
ngx.header["X-My-Header"] = nil;
same does assigning an empty table:
ngx.header["X-My-Header"] = {};
ngx.header
is not a normal Lua table so you cannot
iterate through it.
For reading request headers, use ngx.var.http_HEADER
, that is, nginx's standard $http_HEADER variables:
http://wiki.nginx.org/NginxHttpCoreModule#.24http_HEADER
Reading values from ngx.header.HEADER is not implemented yet, and usually you shouldn't need it.
ngx.exec(uri, args)
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Does an internal redirect to uri with args.
ngx.exec('/some-location');
ngx.exec('/some-location', 'a=3&b=5&c=6');
ngx.exec('/some-location?a=3&b=5', 'c=6');
Named locations are also supported, but query strings are ignored. For example
location /foo {
content_by_lua '
ngx.exec("@bar");
';
}
location @bar {
...
}
Note that this is very different from ngx.redirect() in that it's just an internal redirect and no new HTTP traffic is involved.
This method never returns.
This method MUST be called before ngx.send_headers()
or explicit response body
outputs by either ngx.print
or ngx.say
.
This method is very much like the echo_exec
directive in the ngx_echo module.
ngx.redirect(uri, status?)
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Issue an HTTP 301 or 302 redirection to uri
.
The optional status
parameter specify whether
301 or 302 to be used. It's 302 (ngx.HTTP_MOVED_TEMPORARILY) by default.
Here's a small example:
return ngx.redirect("/foo")
which is equivalent to
return ngx.redirect("http://localhost:1984/foo", ngx.HTTP_MOVED_TEMPORARILY)
assuming the current server name is localhost
and it's listening on the 1984
port.
This method MUST be called before ngx.send_headers()
or explicit response body
outputs by either ngx.print
or ngx.say
.
This method never returns.
This method is very much like the rewrite
directive with the redirect
modifier in the standard
ngx_rewrite
module, for example, this nginx.conf snippet
rewrite ^ /foo redirect; # nginx config
is equivalent to the following Lua code
return ngx.redirect('/foo'); -- lua code
while
rewrite ^ /foo permanent; # nginx config
is equivalent to
return ngx.redirect('/foo', ngx.HTTP_MOVED_PERMANENTLY) -- Lua code
ngx.send_headers()
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Explicitly send out the response headers.
Usually you don't have to send headers yourself. ngx_lua
will automatically send out headers right before you
output contents via ngx.say
or ngx.print
.
Headers will also be sent automatically when content_by_lua
exits normally.
ngx.print(a, b, ...)
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Emit args concatenated to the HTTP client (as response body).
Nil arguments are not allowed.
ngx.say(a, b, ...)
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Just as ngx.print
but also emit a trailing newline.
Nil arguments are not allowed.
ngx.log(log_level, ...)
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Log args concatenated to error.log with the given logging level.
Nil arguments are accepted and result in literal "nil".
ngx.flush()
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Force flushing the response outputs.
ngx.exit(status)
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Interrupts the execution of the current Lua thread and returns status code to nginx.
The status
argument can be ngx.OK
, ngx.ERROR
, ngx.HTTP_NOT_FOUND
,
ngx.HTTP_MOVED_TEMPORARILY
,
or other HTTP status numbers.
ngx.eof()
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Explicitly specify the end of the response output stream.
ngx.escape_uri(str)
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Escape str
as a URI component.
newstr = ngx.escape_uri(str)
ngx.unescape_uri(str)
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Unescape str
as a escaped URI component.
newstr = ngx.unescape_uri(str)
ngx.encode_base64(str)
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Encode str
to a base64 digest
newstr = ngx.encode_base64(str)
ngx.decode_base64(str)
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Decode str
as a base64 digest to the raw form
newstr = ngx.decode_base64(str)
ngx.today()
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Returns today's date (in the format yyyy-mm-dd
) from nginx cached time (no syscall involved unlike Lua's date library).
.
This is the local time.
ngx.time()
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Returns the elapsed seconds from the epoch for the current timestamp from the nginx cached time (no syscall involved unlike Lua's date library).
ngx.localtime()
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Returns the current timestamp (in the format yyyy-mm-dd hh:mm:ss
) of the nginx cached time (no syscall involved unlike Lua's date library).
This is the local time.
ngx.utctime()
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Returns the current timestamp (in the format yyyy-mm-dd hh:mm:ss
) of the nginx cached time (no syscall involved unlike Lua's date library).
This is the UTC time.
ngx.cookie_time(sec)
- Context:
set_by_lua*
,rewrite_by_lua*
,access_by_lua*
,content_by_lua*
Returns a formated string can be used as the cookie expiration time. The parameter sec
is the timestamp in seconds (like those returned from ngx.time
).
ngx.say(ngx.cookie_time(1290079655))
-- yields "Thu, 18-Nov-10 11:27:35 GMT"
ndk.set_var.DIRECTIVE
- Context:
rewrite_by_lua*
,access_by_lua*
,content_by_lua*
This mechanism allows calling other nginx C modules' directives that are implemented by Nginx Devel Kit (NDK)'s set_var submodule's ndk_set_var_value.
For example, ngx_set_misc module's set_escape_uri, set_quote_sql_str, and etc.
For instance,
local res = ndk.set_var.set_escape_uri('a/b');
-- now res == 'a%2fb'
HTTP 1.0 support
Sometimes you may want to use nginx's standard ngx_proxy
module to proxy requests to
another nginx machine configured by a location with content_by_lua
. Because
proxy_pass
only supports the HTTP 1.0 protocol, we have to know
the length of your response body and set the Content-Length
header before emitting
any data out. ngx_lua
will automatically recognize HTTP 1.0 requests and try to send out an appropriate Content-Length
header for you, at the first invocation of ngx.print()
and ngx.say
, assuming all the response body data
is in a single call of ngx.print()
or ngx.say
. So if you want to
support HTTP 1.0 clients like ngx_proxy
, do not
call ngx.print()
or ngx.say()
multiple times,
try buffering the output data yourself wherever needed.
Here is a small example:
On machine A:
location /internal {
rewrite ^/internal/(.*) /lua/$1 break;
proxy_pass http://B;
}
then on machine B:
location = /lua/foo {
content_by_lua '
data = "hello, world"
ngx.print(data)
';
}
Then accessing machine A's /internal/foo using curl gives the result that we expect.
One caveat apples here: always send out the response body data in a single call of ngx.print()
or ngx.say()
, and subsequent calls of ngx.print()
or ngx.say()
will take no effect on the client side.
Performance
The Lua state (aka the Lua vm instance) is shared across all the requests handled by a single nginx worker process to miminize memory use.
On a ThinkPad T400 2.80 GHz laptop, it's easy to achieve 25k req/sec using ab w/o keepalive and 37k+ req/sec with keepalive.
You can get better performance when building this module with LuaJIT 2.0.
Installation
-
Install lua into your system. At least Lua 5.1 is required. Lua can be obtained freely from its project homepage.
-
Download the latest version of the release tarball of the ngx_devel_kit (NDK) module from lua-nginx-module file list.
-
Download the latest version of the release tarball of this module from lua-nginx-module file list.
-
Grab the nginx source code from nginx.net, for example, the version 0.8.54 (see nginx compatibility), and then build the source with this module:
$ wget 'http://sysoev.ru/nginx/nginx-0.8.54.tar.gz' $ tar -xzvf nginx-0.8.54.tar.gz $ cd nginx-0.8.54/ # tell nginx's build system where to find lua: export LUA_LIB=/path/to/lua/lib export LUA_INC=/path/to/lua/include # or tell where to find LuaJIT when you want to use JIT instead # export LUAJIT_LIB=/path/to/luajit/lib # export LUAJIT_INC=/path/to/luajit/include/luajit-2.0 # Here we assume you would install you nginx under /opt/nginx/. $ ./configure --prefix=/opt/nginx \ --add-module=/path/to/ngx_devel_kit \ --add-module=/path/to/lua-nginx-module $ make -j2 $ make install
Compatibility
The following versions of Nginx should work with this module:
- 0.9.x (last tested: 0.9.3)
- 0.8.x (last tested: 0.8.54)
- 0.7.x >= 0.7.46 (last tested: 0.7.68)
Earlier versions of Nginx like 0.6.x and 0.5.x will not work.
Note that rewrite_by_lua
will NOT work for nginx 0.8.41 ~ 0.8.53.
If you find that any particular version of Nginx above 0.7.44 does not work with this module, please consider reporting a bug.
Test Suite
To run the test suite, you also need the following dependencies:
-
Nginx version > 0.8.53
-
Perl modules:
- test-nginx: http://github.com/agentzh/test-nginx
-
Nginx modules:
- echo-nginx-module: http://github.com/agentzh/echo-nginx-module
- drizzle-nginx-module: http://github.com/chaoslawful/drizzle-nginx-module
- rds-json-nginx-module: http://github.com/agentzh/rds-json-nginx-module
- set-misc-nginx-module: http://github.com/agentzh/set-misc-nginx-module
- memc-nginx-module: http://github.com/agentzh/memc-nginx-module
- srcache-nginx-module: http://github.com/agentzh/srcache-nginx-module
- ngx_auth_request: http://mdounin.ru/hg/ngx_http_auth_request_module/
-
C libraries:
-
Lua modules:
- lua-yajl: https://github.com/brimworks/lua-yajl
- Note: the compiled module has to be placed in '/usr/local/lib/lua/5.1/'
- lua-yajl: https://github.com/brimworks/lua-yajl
-
Applications:
- mysql: create database 'ngx_test', grant all privileges to user 'ngx_test', password is 'ngx_test'
- memcached
These module's adding order is IMPORTANT! For filter modules's position in filtering chain affects a lot. The correct configure adding order is:
- ngx_devel_kit
- set-misc-nginx-module
- ngx_http_auth_request_module
- echo-nginx-module
- memc-nginx-module
- lua-nginx-module (i.e. this module)
- srcache-nginx-module
- drizzle-nginx-module
- rds-json-nginx-module
TODO
- Add directives to run lua codes when nginx stops/reloads.
- Add
ngx.location.capture_multi
to allow multiple parallel subrequests. - Deal with TCP 3-second delay problem under great connection harness.
- Add
lua_code_cache on|off
directive to allow .lua files updated on-the-fly during development.
Future Plan
- Add 'lua_require' directive to load module into main thread's globals
- Add Lua VM passive yield and resume (using debug hook)
- Make set_by_lua using the same mechanism as content_by_lua
Known Issues
-
WATCH OUT: Globals WON'T persist between requests, because of the one-coroutine-per-request isolation design. Especially watch yourself when using
require()
to import modules, and use this form:local xxx = require('xxx')
instead of the old deprecated form:
require('xxx')
The old form will cause module unusable in requests for the reason told previously. If you have to stick with the old form, you can always force loading module for every request by clean
package.loaded.<module>
, like this:package.loaded.xxx = nil require('xxx')
-
64-bit Darwin OS needs special linking options to use LuaJIT. Change the line at the bottom of
config
file fromCORE_LIBS="-Wl,-E $CORE_LIBS"
to
CORE_LIBS="-Wl,-E -Wl,-pagezero_size,10000 -Wl,-image_base,100000000 $CORE_LIBS"
See Also
- "Introduction to ngx_lua" ( https://github.com/chaoslawful/lua-nginx-module/wiki/Introduction )
- ngx_devel_kit ( http://github.com/simpl/ngx_devel_kit )
- echo-nginx-module ( http://github.com/agentzh/echo-nginx-module )
- drizzle-nginx-module ( http://github.com/chaoslawful/drizzle-nginx-module )
- postgres-nginx-module ( http://github.com/FRiCKLE/ngx_postgres )
- memc-nginx-module ( http://github.com/agentzh/memc-nginx-module )
Authors
- chaoslawful (王晓哲)
- Yichun "agentzh" Zhang (章亦春)
Copyright & License
This module is licenced under the BSD license.
Copyright (C) 2009, 2010, 2011 Taobao Inc., Alibaba Group ( http://www.taobao.com ).
Copyright (C) 2009, 2010, 2011 by Xiaozhe Wang (chaoslawful) <chaoslawful@gmail.com>.
Copyright (C) 2009, 2010, 2011 by Yichun "agentzh" Zhang <agentzh@gmail.com>.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.