[doc] dos2unix doc/magnet.txt
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2402 152afb58-edef-0310-8abb-c4023f1b3aa9
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doc/magnet.txt
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doc/magnet.txt
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{{{
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#!rst
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==============
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a power-magnet
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==============
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------------------
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Module: mod_magnet
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------------------
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.. contents:: Table of Contents
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Requirements
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============
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:Version: lighttpd 1.4.12 or higher
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:Packages: lua >= 5.1
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Overview
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========
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mod_magnet is a module to control the request handling in lighty.
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.. note::
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Keep in mind that the magnet is executed in the core of lighty. EVERY long-running operation is blocking
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ALL connections in the server. You are warned. For time-consuming or blocking scripts use mod_fastcgi and friends.
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For performance reasons mod_magnet caches the compiled script. For each script-run the script itself is checked for
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freshness and recompile if neccesary.
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Installation
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============
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mod_magnet needs a lighty which is compiled with the lua-support ( --with-lua). Lua 5.1 or higher are required by
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the module. Use "--with-lua=lua5.1" to install on Debian and friends. ::
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server.modules = ( ..., "mod_magnet", ... )
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Options
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=======
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mod_magnet can attract a request in several stages in the request-handling.
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* either at the same level as mod_rewrite, before any parsing of the URL is done
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* or at a later stage, when the doc-root is known and the physical-path is already setup
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It depends on the purpose of the script which stage you want to intercept. Usually you want to use
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the 2nd stage where the physical-path which relates to your request is known. At this level you
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can run checks against lighty.env["physical.path"].
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::
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magnet.attract-raw-url-to = ( ... )
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magnet.attract-physical-path-to = ( ... )
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You can define multiple scripts when separated by a semicolon. The scripts are executed in the specified
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order. If one of them a returning a status-code, the following scripts will not be executed.
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Tables
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======
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Most of the interaction between between mod_magnet and lighty is done through tables. Tables in lua are hashes (Perl), dictionaries (Java), arrays (PHP), ...
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Request-Environment
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-------------------
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Lighttpd has its internal variables which are exported as read/write to the magnet.
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If "http://example.org/search.php?q=lighty" is requested this results in a request like ::
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GET /search.php?q=lighty HTTP/1.1
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Host: example.org
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When you are using ``attract-raw-url-to`` you can access the following variables:
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* parts of the request-line
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* lighty.env["request.uri"] = "/search.php?q=lighty"
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* HTTP request-headers
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* lighty.request["Host"] = "example.org"
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Later in the request-handling, the URL is splitted, cleaned up and turned into a physical path name:
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* parts of the URI
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* lighty.env["uri.path"] = "/search.php"
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* lighty.env["uri.path-raw"] = "/search.php"
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* lighty.env["uri.scheme"] = "http"
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* lighty.env["uri.authority"] = "example.org"
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* lighty.env["uri.query"] = "q=lighty"
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* filenames, pathnames
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* lighty.env["physical.path"] = "/my-docroot/search.php"
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* lighty.env["physical.rel-path"] = "/search.php"
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* lighty.env["physical.doc-root"] = "/my-docroot"
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All of them are readable, not all of the are writable (or don't have an effect if you write to them).
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As a start, you might want to use those variables for writing: ::
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-- 1. simple rewriting is done via the request.uri
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lighty.env["request.uri"] = ...
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return lighty.RESTART_REQUEST
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-- 2. changing the physical-path
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lighty.env["physical.path"] = ...
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-- 3. changing the query-string
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lighty.env["uri.query"] = ...
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Response Headers
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----------------
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If you want to set a response header for your request, you can add a field to the lighty.header[] table: ::
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lighty.header["Content-Type"] = "text/html"
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Sending Content
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===============
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You can generate your own content and send it out to the clients. ::
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lighty.content = { "<pre>", { filename = "/etc/passwd" }, "</pre>" }
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lighty.header["Content-Type"] = "text/html"
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return 200
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The lighty.content[] table is executed when the script is finished. The elements of the array are processed left to right and the elements can either be a string or a table. Strings are included AS IS into the output of the request.
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* Strings
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* are included as is
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* Tables
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* filename = "<absolute-path>" is required
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* offset = <number> [default: 0]
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* length = <number> [default: size of the file - offset]
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Internally lighty will use the sendfile() call to send out the static files at full speed.
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Status Codes
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============
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You might have seen it already in other examples: In case you are handling the request completly in the magnet you
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can return your own status-codes. Examples are: Redirected, Input Validation, ... ::
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if (lighty.env["uri.scheme"] == "http") then
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lighty.header["Location"] = "https://" .. lighty.env["uri.authority"] .. lighty.env["request.uri"]
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return 302
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end
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You every number above and equal to 100 is taken as final status code and finishes the request. No other modules are
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executed after this return.
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A special return-code is lighty.RESTART_REQUEST (currently equal to 99) which is usually used in combination with
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changing the request.uri in a rewrite. It restarts the splitting of the request-uri again.
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If you return nothing (or nil) the request-handling just continues.
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Debugging
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=========
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To easy debugging we overloaded the print()-function in lua and redirect the output of print() to the error-log. ::
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print("Host: " .. lighty.request["Host"])
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print("Request-URI: " .. lighty.env["request.uri"])
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Examples
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========
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Sending text-files as HTML
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--------------------------
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This is a bit simplistic, but it illustrates the idea: Take a text-file and cover it in a <pre> tag.
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Config-file ::
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magnet.attract-physical-path-to = server.docroot + "/readme.lua"
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readme.lua ::
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lighty.content = { "<pre>", { filename = "/README" }, "</pre>" }
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lighty.header["Content-Type"] = "text/html"
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return 200
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Maintainance pages
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------------------
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Your side might be on maintainance from time to time. Instead of shutting down the server confusing all
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users, you can just send a maintainance page.
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Config-file ::
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magnet.attract-physical-path-to = server.docroot + "/maintainance.lua"
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maintainance.lua ::
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require "lfs"
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if (nil == lfs.attributes(lighty.env["physical.doc-root"] .. "/maintainance.html")) then
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lighty.content = ( lighty.env["physical.doc-root"] .. "/maintainance.html" )
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lighty.header["Content-Type"] = "text/html"
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return 200
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end
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mod_flv_streaming
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-----------------
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Config-file ::
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magnet.attract-physical-path-to = server.docroot + "/flv-streaming.lua"
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flv-streaming.lua::
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if (lighty.env["uri.query"]) then
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-- split the query-string
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get = {}
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for k, v in string.gmatch(lighty.env["uri.query"], "(%w+)=(%w+)") do
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get[k] = v
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end
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if (get["start"]) then
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-- missing: check if start is numeric and positive
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-- send te FLV header + a seek into the file
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lighty.content = { "FLV\x1\x1\0\0\0\x9\0\0\0\x9",
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{ filename = lighty.env["physical.path"], offset = get["start"] } }
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lighty.header["Content-Type"] = "video/x-flv"
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return 200
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end
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end
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selecting a random file from a directory
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----------------------------------------
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Say, you want to send a random file (ad-content) from a directory.
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To simplify the code and to improve the performance we define:
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* all images have the same format (e.g. image/png)
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* all images use increasing numbers starting from 1
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* a special index-file names the highest number
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Config ::
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server.modules += ( "mod_magnet" )
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magnet.attract-physical-path-to = "random.lua"
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random.lua ::
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dir = lighty.env["physical.path"]
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f = assert(io.open(dir .. "/index", "r"))
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maxndx = f:read("*all")
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f:close()
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ndx = math.random(maxndx)
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lighty.content = { { filename = dir .. "/" .. ndx }}
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lighty.header["Content-Type"] = "image/png"
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return 200
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denying illegal character sequences in the URL
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----------------------------------------------
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Instead of implementing mod_security, you might just want to apply filters on the content
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and deny special sequences that look like SQL injection.
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A common injection is using UNION to extend a query with another SELECT query.
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::
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if (string.find(lighty.env["request.uri"], "UNION%s")) then
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return 400
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end
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Traffic Quotas
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--------------
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If you only allow your virtual hosts a certain amount for traffic each month and want to
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disable them if the traffic is reached, perhaps this helps: ::
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host_blacklist = { ["www.example.org"] = 0 }
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if (host_blacklist[lighty.request["Host"]]) then
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return 404
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end
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Just add the hosts you want to blacklist into the blacklist table in the shown way.
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Complex rewrites
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----------------
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If you want to implement caching on your document-root and only want to regenerate
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content if the requested file doesn't exist, you can attract the physical.path: ::
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magnet.attract-physical-path-to = ( server.document-root + "/rewrite.lua" )
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rewrite.lua ::
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require "lfs"
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attr = lfs.attributes(lighty.env["physical.path"])
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if (not attr) then
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-- we couldn't stat() the file for some reason
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-- let the backend generate it
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lighty.env["uri.path"] = "/dispatch.fcgi"
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lighty.env["physical.rel-path"] = lighty.env["uri.path"]
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lighty.env["physical.path"] = lighty.env["physical.doc-root"] .. lighty.env["physical.rel-path"]
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fi
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luafilesystem
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+++++++++++++
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We are requiring the lua-module 'lfs' (http://www.keplerproject.org/luafilesystem/).
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I had to compile lfs myself for lua-5.1 which required a minor patch as compat-5.1 is not needed::
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$ wget http://luaforge.net/frs/download.php/1487/luafilesystem-1.2.tar.gz
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$ wget http://www.lighttpd.net/download/luafilesystem-1.2-lua51.diff
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$ gzip -cd luafilesystem-1.2.tar.gz | tar xf -
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$ cd luafilesystem-1.2
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$ patch -ls -p1 < ../luafilesystem-1.2-lua51.diff
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$ make install
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It will install lfs.so into /usr/lib/lua/5.1/ which is where lua expects the extensions on my system.
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SuSE and Gentoo are known to have their own lfs packages and don't require a compile.
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Usertracking
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------------
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... or how to store data globally in the script-context:
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Each script has its own script-context. When the script is started it only contains the lua-functions
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and the special lighty.* name-space. If you want to save data between script runs, you can use the global-script
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context:
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::
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if (nil == _G["usertrack"]) then
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_G["usertrack"] = {}
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end
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if (nil == _G["usertrack"][lighty.request["Cookie"]]) then
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_G["usertrack"][lighty.request["Cookie"]]
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else
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_G["usertrack"][lighty.request["Cookie"]] = _G["usertrack"][lighty.request["Cookie"]] + 1
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end
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print _G["usertrack"][lighty.request["Cookie"]]
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The global-context is per script. If you update the script without restarting the server, the context will still be maintained.
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Counters
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--------
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mod_status support a global statistics page and mod_magnet allows to add and update values in the status page:
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Config ::
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status.statistics-url = "/server-counters"
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magnet.attract-raw-url-to = server.docroot + "/counter.lua"
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counter.lua ::
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lighty.status["core.connections"] = lighty.status["core.connections"] + 1
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Result::
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core.connections: 7
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fastcgi.backend.php-foo.0.connected: 0
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fastcgi.backend.php-foo.0.died: 0
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fastcgi.backend.php-foo.0.disabled: 0
|
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fastcgi.backend.php-foo.0.load: 0
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fastcgi.backend.php-foo.0.overloaded: 0
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fastcgi.backend.php-foo.1.connected: 0
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fastcgi.backend.php-foo.1.died: 0
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fastcgi.backend.php-foo.1.disabled: 0
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fastcgi.backend.php-foo.1.load: 0
|
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fastcgi.backend.php-foo.1.overloaded: 0
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fastcgi.backend.php-foo.load: 0
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Porting mod_cml scripts
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-----------------------
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mod_cml got replaced by mod_magnet.
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A CACHE_HIT in mod_cml::
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output_include = { "file1", "file2" }
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return CACHE_HIT
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becomes::
|
||||
|
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content = { { filename = "/path/to/file1" }, { filename = "/path/to/file2"} }
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return 200
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while a CACHE_MISS like (CML) ::
|
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trigger_handler = "/index.php"
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return CACHE_MISS
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becomes (magnet) ::
|
||||
|
||||
lighty.env["request.uri"] = "/index.php"
|
||||
|
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return lighty.RESTART_REQUEST
|
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|
||||
}}}
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||||
{{{
|
||||
#!rst
|
||||
==============
|
||||
a power-magnet
|
||||
==============
|
||||
|
||||
------------------
|
||||
Module: mod_magnet
|
||||
------------------
|
||||
|
||||
|
||||
|
||||
.. contents:: Table of Contents
|
||||
|
||||
Requirements
|
||||
============
|
||||
|
||||
:Version: lighttpd 1.4.12 or higher
|
||||
:Packages: lua >= 5.1
|
||||
|
||||
Overview
|
||||
========
|
||||
|
||||
mod_magnet is a module to control the request handling in lighty.
|
||||
|
||||
.. note::
|
||||
|
||||
Keep in mind that the magnet is executed in the core of lighty. EVERY long-running operation is blocking
|
||||
ALL connections in the server. You are warned. For time-consuming or blocking scripts use mod_fastcgi and friends.
|
||||
|
||||
For performance reasons mod_magnet caches the compiled script. For each script-run the script itself is checked for
|
||||
freshness and recompile if neccesary.
|
||||
|
||||
|
||||
Installation
|
||||
============
|
||||
|
||||
mod_magnet needs a lighty which is compiled with the lua-support ( --with-lua). Lua 5.1 or higher are required by
|
||||
the module. Use "--with-lua=lua5.1" to install on Debian and friends. ::
|
||||
|
||||
server.modules = ( ..., "mod_magnet", ... )
|
||||
|
||||
Options
|
||||
=======
|
||||
|
||||
mod_magnet can attract a request in several stages in the request-handling.
|
||||
|
||||
* either at the same level as mod_rewrite, before any parsing of the URL is done
|
||||
* or at a later stage, when the doc-root is known and the physical-path is already setup
|
||||
|
||||
It depends on the purpose of the script which stage you want to intercept. Usually you want to use
|
||||
the 2nd stage where the physical-path which relates to your request is known. At this level you
|
||||
can run checks against lighty.env["physical.path"].
|
||||
|
||||
::
|
||||
|
||||
magnet.attract-raw-url-to = ( ... )
|
||||
magnet.attract-physical-path-to = ( ... )
|
||||
|
||||
You can define multiple scripts when separated by a semicolon. The scripts are executed in the specified
|
||||
order. If one of them a returning a status-code, the following scripts will not be executed.
|
||||
|
||||
Tables
|
||||
======
|
||||
|
||||
Most of the interaction between between mod_magnet and lighty is done through tables. Tables in lua are hashes (Perl), dictionaries (Java), arrays (PHP), ...
|
||||
|
||||
Request-Environment
|
||||
-------------------
|
||||
|
||||
Lighttpd has its internal variables which are exported as read/write to the magnet.
|
||||
|
||||
If "http://example.org/search.php?q=lighty" is requested this results in a request like ::
|
||||
|
||||
GET /search.php?q=lighty HTTP/1.1
|
||||
Host: example.org
|
||||
|
||||
When you are using ``attract-raw-url-to`` you can access the following variables:
|
||||
|
||||
* parts of the request-line
|
||||
|
||||
* lighty.env["request.uri"] = "/search.php?q=lighty"
|
||||
|
||||
* HTTP request-headers
|
||||
|
||||
* lighty.request["Host"] = "example.org"
|
||||
|
||||
Later in the request-handling, the URL is splitted, cleaned up and turned into a physical path name:
|
||||
|
||||
* parts of the URI
|
||||
|
||||
* lighty.env["uri.path"] = "/search.php"
|
||||
* lighty.env["uri.path-raw"] = "/search.php"
|
||||
* lighty.env["uri.scheme"] = "http"
|
||||
* lighty.env["uri.authority"] = "example.org"
|
||||
* lighty.env["uri.query"] = "q=lighty"
|
||||
|
||||
* filenames, pathnames
|
||||
|
||||
* lighty.env["physical.path"] = "/my-docroot/search.php"
|
||||
* lighty.env["physical.rel-path"] = "/search.php"
|
||||
* lighty.env["physical.doc-root"] = "/my-docroot"
|
||||
|
||||
All of them are readable, not all of the are writable (or don't have an effect if you write to them).
|
||||
|
||||
As a start, you might want to use those variables for writing: ::
|
||||
|
||||
-- 1. simple rewriting is done via the request.uri
|
||||
lighty.env["request.uri"] = ...
|
||||
return lighty.RESTART_REQUEST
|
||||
|
||||
-- 2. changing the physical-path
|
||||
lighty.env["physical.path"] = ...
|
||||
|
||||
-- 3. changing the query-string
|
||||
lighty.env["uri.query"] = ...
|
||||
|
||||
Response Headers
|
||||
----------------
|
||||
|
||||
If you want to set a response header for your request, you can add a field to the lighty.header[] table: ::
|
||||
|
||||
lighty.header["Content-Type"] = "text/html"
|
||||
|
||||
Sending Content
|
||||
===============
|
||||
|
||||
You can generate your own content and send it out to the clients. ::
|
||||
|
||||
lighty.content = { "<pre>", { filename = "/etc/passwd" }, "</pre>" }
|
||||
lighty.header["Content-Type"] = "text/html"
|
||||
|
||||
return 200
|
||||
|
||||
The lighty.content[] table is executed when the script is finished. The elements of the array are processed left to right and the elements can either be a string or a table. Strings are included AS IS into the output of the request.
|
||||
|
||||
* Strings
|
||||
|
||||
* are included as is
|
||||
|
||||
* Tables
|
||||
|
||||
* filename = "<absolute-path>" is required
|
||||
* offset = <number> [default: 0]
|
||||
* length = <number> [default: size of the file - offset]
|
||||
|
||||
Internally lighty will use the sendfile() call to send out the static files at full speed.
|
||||
|
||||
Status Codes
|
||||
============
|
||||
|
||||
You might have seen it already in other examples: In case you are handling the request completly in the magnet you
|
||||
can return your own status-codes. Examples are: Redirected, Input Validation, ... ::
|
||||
|
||||
if (lighty.env["uri.scheme"] == "http") then
|
||||
lighty.header["Location"] = "https://" .. lighty.env["uri.authority"] .. lighty.env["request.uri"]
|
||||
return 302
|
||||
end
|
||||
|
||||
You every number above and equal to 100 is taken as final status code and finishes the request. No other modules are
|
||||
executed after this return.
|
||||
|
||||
A special return-code is lighty.RESTART_REQUEST (currently equal to 99) which is usually used in combination with
|
||||
changing the request.uri in a rewrite. It restarts the splitting of the request-uri again.
|
||||
|
||||
If you return nothing (or nil) the request-handling just continues.
|
||||
|
||||
Debugging
|
||||
=========
|
||||
|
||||
To easy debugging we overloaded the print()-function in lua and redirect the output of print() to the error-log. ::
|
||||
|
||||
print("Host: " .. lighty.request["Host"])
|
||||
print("Request-URI: " .. lighty.env["request.uri"])
|
||||
|
||||
|
||||
Examples
|
||||
========
|
||||
|
||||
Sending text-files as HTML
|
||||
--------------------------
|
||||
|
||||
This is a bit simplistic, but it illustrates the idea: Take a text-file and cover it in a <pre> tag.
|
||||
|
||||
Config-file ::
|
||||
|
||||
magnet.attract-physical-path-to = server.docroot + "/readme.lua"
|
||||
|
||||
readme.lua ::
|
||||
|
||||
lighty.content = { "<pre>", { filename = "/README" }, "</pre>" }
|
||||
lighty.header["Content-Type"] = "text/html"
|
||||
|
||||
return 200
|
||||
|
||||
Maintainance pages
|
||||
------------------
|
||||
|
||||
Your side might be on maintainance from time to time. Instead of shutting down the server confusing all
|
||||
users, you can just send a maintainance page.
|
||||
|
||||
Config-file ::
|
||||
|
||||
magnet.attract-physical-path-to = server.docroot + "/maintainance.lua"
|
||||
|
||||
maintainance.lua ::
|
||||
|
||||
require "lfs"
|
||||
|
||||
if (nil == lfs.attributes(lighty.env["physical.doc-root"] .. "/maintainance.html")) then
|
||||
lighty.content = ( lighty.env["physical.doc-root"] .. "/maintainance.html" )
|
||||
|
||||
lighty.header["Content-Type"] = "text/html"
|
||||
|
||||
return 200
|
||||
end
|
||||
|
||||
mod_flv_streaming
|
||||
-----------------
|
||||
|
||||
Config-file ::
|
||||
|
||||
magnet.attract-physical-path-to = server.docroot + "/flv-streaming.lua"
|
||||
|
||||
flv-streaming.lua::
|
||||
|
||||
if (lighty.env["uri.query"]) then
|
||||
-- split the query-string
|
||||
get = {}
|
||||
for k, v in string.gmatch(lighty.env["uri.query"], "(%w+)=(%w+)") do
|
||||
get[k] = v
|
||||
end
|
||||
|
||||
if (get["start"]) then
|
||||
-- missing: check if start is numeric and positive
|
||||
|
||||
-- send te FLV header + a seek into the file
|
||||
lighty.content = { "FLV\x1\x1\0\0\0\x9\0\0\0\x9",
|
||||
{ filename = lighty.env["physical.path"], offset = get["start"] } }
|
||||
lighty.header["Content-Type"] = "video/x-flv"
|
||||
|
||||
return 200
|
||||
end
|
||||
end
|
||||
|
||||
|
||||
selecting a random file from a directory
|
||||
----------------------------------------
|
||||
|
||||
Say, you want to send a random file (ad-content) from a directory.
|
||||
|
||||
To simplify the code and to improve the performance we define:
|
||||
|
||||
* all images have the same format (e.g. image/png)
|
||||
* all images use increasing numbers starting from 1
|
||||
* a special index-file names the highest number
|
||||
|
||||
Config ::
|
||||
|
||||
server.modules += ( "mod_magnet" )
|
||||
magnet.attract-physical-path-to = "random.lua"
|
||||
|
||||
random.lua ::
|
||||
|
||||
dir = lighty.env["physical.path"]
|
||||
|
||||
f = assert(io.open(dir .. "/index", "r"))
|
||||
maxndx = f:read("*all")
|
||||
f:close()
|
||||
|
||||
ndx = math.random(maxndx)
|
||||
|
||||
lighty.content = { { filename = dir .. "/" .. ndx }}
|
||||
lighty.header["Content-Type"] = "image/png"
|
||||
|
||||
return 200
|
||||
|
||||
denying illegal character sequences in the URL
|
||||
----------------------------------------------
|
||||
|
||||
Instead of implementing mod_security, you might just want to apply filters on the content
|
||||
and deny special sequences that look like SQL injection.
|
||||
|
||||
A common injection is using UNION to extend a query with another SELECT query.
|
||||
|
||||
::
|
||||
|
||||
if (string.find(lighty.env["request.uri"], "UNION%s")) then
|
||||
return 400
|
||||
end
|
||||
|
||||
Traffic Quotas
|
||||
--------------
|
||||
|
||||
If you only allow your virtual hosts a certain amount for traffic each month and want to
|
||||
disable them if the traffic is reached, perhaps this helps: ::
|
||||
|
||||
host_blacklist = { ["www.example.org"] = 0 }
|
||||
|
||||
if (host_blacklist[lighty.request["Host"]]) then
|
||||
return 404
|
||||
end
|
||||
|
||||
Just add the hosts you want to blacklist into the blacklist table in the shown way.
|
||||
|
||||
Complex rewrites
|
||||
----------------
|
||||
|
||||
If you want to implement caching on your document-root and only want to regenerate
|
||||
content if the requested file doesn't exist, you can attract the physical.path: ::
|
||||
|
||||
magnet.attract-physical-path-to = ( server.document-root + "/rewrite.lua" )
|
||||
|
||||
rewrite.lua ::
|
||||
|
||||
require "lfs"
|
||||
|
||||
attr = lfs.attributes(lighty.env["physical.path"])
|
||||
|
||||
if (not attr) then
|
||||
-- we couldn't stat() the file for some reason
|
||||
-- let the backend generate it
|
||||
|
||||
lighty.env["uri.path"] = "/dispatch.fcgi"
|
||||
lighty.env["physical.rel-path"] = lighty.env["uri.path"]
|
||||
lighty.env["physical.path"] = lighty.env["physical.doc-root"] .. lighty.env["physical.rel-path"]
|
||||
fi
|
||||
|
||||
luafilesystem
|
||||
+++++++++++++
|
||||
|
||||
We are requiring the lua-module 'lfs' (http://www.keplerproject.org/luafilesystem/).
|
||||
|
||||
I had to compile lfs myself for lua-5.1 which required a minor patch as compat-5.1 is not needed::
|
||||
|
||||
$ wget http://luaforge.net/frs/download.php/1487/luafilesystem-1.2.tar.gz
|
||||
$ wget http://www.lighttpd.net/download/luafilesystem-1.2-lua51.diff
|
||||
$ gzip -cd luafilesystem-1.2.tar.gz | tar xf -
|
||||
$ cd luafilesystem-1.2
|
||||
$ patch -ls -p1 < ../luafilesystem-1.2-lua51.diff
|
||||
$ make install
|
||||
|
||||
It will install lfs.so into /usr/lib/lua/5.1/ which is where lua expects the extensions on my system.
|
||||
|
||||
SuSE and Gentoo are known to have their own lfs packages and don't require a compile.
|
||||
|
||||
Usertracking
|
||||
------------
|
||||
|
||||
... or how to store data globally in the script-context:
|
||||
|
||||
Each script has its own script-context. When the script is started it only contains the lua-functions
|
||||
and the special lighty.* name-space. If you want to save data between script runs, you can use the global-script
|
||||
context:
|
||||
|
||||
::
|
||||
|
||||
if (nil == _G["usertrack"]) then
|
||||
_G["usertrack"] = {}
|
||||
end
|
||||
if (nil == _G["usertrack"][lighty.request["Cookie"]]) then
|
||||
_G["usertrack"][lighty.request["Cookie"]]
|
||||
else
|
||||
_G["usertrack"][lighty.request["Cookie"]] = _G["usertrack"][lighty.request["Cookie"]] + 1
|
||||
end
|
||||
|
||||
print _G["usertrack"][lighty.request["Cookie"]]
|
||||
|
||||
The global-context is per script. If you update the script without restarting the server, the context will still be maintained.
|
||||
|
||||
Counters
|
||||
--------
|
||||
|
||||
mod_status support a global statistics page and mod_magnet allows to add and update values in the status page:
|
||||
|
||||
Config ::
|
||||
|
||||
status.statistics-url = "/server-counters"
|
||||
magnet.attract-raw-url-to = server.docroot + "/counter.lua"
|
||||
|
||||
counter.lua ::
|
||||
|
||||
lighty.status["core.connections"] = lighty.status["core.connections"] + 1
|
||||
|
||||
Result::
|
||||
|
||||
core.connections: 7
|
||||
fastcgi.backend.php-foo.0.connected: 0
|
||||
fastcgi.backend.php-foo.0.died: 0
|
||||
fastcgi.backend.php-foo.0.disabled: 0
|
||||
fastcgi.backend.php-foo.0.load: 0
|
||||
fastcgi.backend.php-foo.0.overloaded: 0
|
||||
fastcgi.backend.php-foo.1.connected: 0
|
||||
fastcgi.backend.php-foo.1.died: 0
|
||||
fastcgi.backend.php-foo.1.disabled: 0
|
||||
fastcgi.backend.php-foo.1.load: 0
|
||||
fastcgi.backend.php-foo.1.overloaded: 0
|
||||
fastcgi.backend.php-foo.load: 0
|
||||
|
||||
Porting mod_cml scripts
|
||||
-----------------------
|
||||
|
||||
mod_cml got replaced by mod_magnet.
|
||||
|
||||
A CACHE_HIT in mod_cml::
|
||||
|
||||
output_include = { "file1", "file2" }
|
||||
|
||||
return CACHE_HIT
|
||||
|
||||
becomes::
|
||||
|
||||
content = { { filename = "/path/to/file1" }, { filename = "/path/to/file2"} }
|
||||
|
||||
return 200
|
||||
|
||||
while a CACHE_MISS like (CML) ::
|
||||
|
||||
trigger_handler = "/index.php"
|
||||
|
||||
return CACHE_MISS
|
||||
|
||||
becomes (magnet) ::
|
||||
|
||||
lighty.env["request.uri"] = "/index.php"
|
||||
|
||||
return lighty.RESTART_REQUEST
|
||||
|
||||
}}}
|
||||
|
|
|
|||
Loading…
Reference in New Issue