xavante运行cgilua流程

安装软件

需要安装三个lua 库：  xavante wsapi cgilua

luarocks install xavante

http://keplerproject.github.io/xavante/manual.html#install

Xavante is a Lua HTTP 1.1 Web server that uses a modular architecture based on URI mapped handlers. Xavante currently offers a file handler, a redirect handler and a WSAPI handler. Those are used for general files, URI remapping and WSAPI applications respectively.

luarocks install wsapi-xavante

http://keplerproject.github.io/wsapi/index.html

WSAPI is an API that abstracts the web server from Lua web applications. By coding against WSAPI your application can run on any of the supported servers and interfaces (currently CGI, FastCGI and Xavante, on Windows and UNIX-based systems).

https://github.com/keplerproject/wsapi

cgilua

luarocks install cgilua

https://github.com/keplerproject/cgilua

CGILua is a tool for creating dynamic Web pages and manipulating input data from Web forms. CGILua allows the separation of logic and data handling from the generation of pages, making it easy to develop web applications with Lua.

运行脚本

切换到cgilua样例目录

root@fqs:/home/share/cgilua-master/cgilua-master/examples# lua xavante_cgilua.lua
[2016-06-22 22:16:50] Xavante started on port(s) 8080

脚本内容 laucher：

xavante = require "xavante"
xavante.filehandler = require "xavante.filehandler"
xavante.cgiluahandler = require "xavante.cgiluahandler"
xavante.redirecthandler = require "xavante.redirecthandler"

-- Define here where Xavante HTTP documents scripts are located
local webDir = "."

local simplerules = {

   { -- URI remapping example
      match = "^[^%./]*/$",
      with = xavante.redirecthandler,
      params = {"index.lp"}
   },

   { -- cgiluahandler example
      match = {"%.lp$", "%.lp/.*$", "%.lua$", "%.lua/.*$" },
      with = xavante.cgiluahandler.makeHandler (webDir)
   },
   
   { -- filehandler example
      match = ".",
      with = xavante.filehandler,
      params = {baseDir = webDir}
   },
}

xavante.HTTP{
   server = {host = "*", port = 8080},
   
   defaultHost = {
      rules = simplerules
   },
}

-- Displays a message in the console with the used ports
xavante.start_message(function (ports)
    local date = os.date("[%Y-%m-%d %H:%M:%S]")
    print(string.format("%s Xavante started on port(s) %s",
                date, table.concat(ports, ", ")))
end)

xavante.start()

WSAPI Xavante 安装后自带launcher

http://keplerproject.github.io/wsapi/manual.html

Xavante

If you installed the wsapi-xavante package you already have a Xavante launcher with WSAPI support. Just run the wsapi script in the path you want as your document root, and point your browser either to the hello.lua or hello.ws script (both extensions are treated as WSAPI applications). See wsapi --help for the launcher's configuration options.

launcher：

root@fqs:/usr/local/bin# cat wsapi
#!/bin/sh

exec '/usr/bin/lua5.1' -e 'package.path="/root/.luarocks/share/lua/5.1/?.lua;/root/.luarocks/share/lua/5.1/?/init.lua;/usr/local/share/lua/5.1/?.lua;/usr/local/share/lua/5.1/?/init.lua;"..package.path; package.cpath="/root/.luarocks/lib/lua/5.1/?.so;/usr/local/lib/lua/5.1/?.so;"..package.cpath' -e 'local k,l,_=pcall(require,"luarocks.loader") _=k and l.add_context("wsapi-xavante","1.6.1-1")' '/usr/local/lib/luarocks/rocks/wsapi-xavante/1.6.1-1/bin/wsapi' "$@"

root@fqs:/usr/local/bin#

主要实现在 '/usr/local/lib/luarocks/rocks/wsapi/1.6.1-1/bin/wsapi'

此内容，与运行脚本章节的 launcher 功能角色上相同， 但是其比较完善。

root@fqs:/usr/local/bin# cat /usr/local/lib/luarocks/rocks/wsapi-xavante/1.6.1-1/bin/wsapi
#!/usr/bin/env lua

local lfs = require "lfs"
local util = require "wsapi.util"
local wsx = require "wsapi.xavante"
local xavante = require "xavante"
local filehandler = require "xavante.filehandler"
local redirecthandler = require "xavante.redirecthandler"

local usage = [[
Usage: wsapi [options] [document root]

Starts a Xavante instance to serve static files and WSAPI applications.
Treats .lua and .ws files as WSAPI applications, and everything else as
static (but see the --cgilua and --op options, below).

The default document root is the current path.

Options:

-c<file>, --config=<file>   Runs the specified file for additional
                            configuration before starting the server
-l<file>, --log=<file>      Logs all output to the file (default stdout
                            and stderr)
-p<port>, --port=<port>     Binds to the specified port (default 8080)
--cgilua                    Adds .lp and .cgi rules for CGILua pages and
                            scripts
--op                        Adds an .op rule that for Orbit pages
-r, --reload                Reloads applications on every request
-h, --help                  Shows this help screen

]]

local config = {}

local opts, args = util.getopt({ ... }, "clp")

if opts.h or opts.help then
  print(usage)
  os.exit()
end

local config = {
  docroot = args[1] or lfs.currentdir(),
  logfile = opts.l or opts.log,
  port = tonumber(opts.p or opts.port) or 8080,
  start_message = function (ports)
                     local date = os.date("[%Y-%m-%d %H:%M:%S]")
                     print(string.format("%s Xavante started on port(s) %s",
                                         date, table.concat(ports, ", ")))
                  end,
  rules = {},
  is_finished = function() return false end,
  reload = opts.r or opts.reload,
  isolated = true
}

local config_file = opts.c or opts.config

if config_file then
  local f, err = util.loadfile(config_file, setmetatable(config, { __index = _G }))
  if not f then
    io.stderr:write("Cannot load config file " .. config_file .. ": " .. err .. " ")
    os.exit()
  end
  local res, err = pcall(f)
  if not res then
    io.stderr:write("Error in config file: " .. err .. " ")
    os.exit()
  end
  setmetatable(config, nil)
end

if config.logfile then
  local tostring = tostring
  local log = io.open(config.logfile, "a+")
  if not log then
    error("Could not open log file. Please check the write permissions for: " .. config.logfile)
  end
  io.stdout = log
  io.stderr = log
  print = function (...)
    local nargs = select('#', ...)
    for i = 1, nargs-1 do
      log:write(tostring((select(i, ...))))
      log:write(" ")
    end
    log:write(tostring(select(nargs, ...)))
    log:write(" ")
  end
end

local ONE_HOUR = 60 * 60
local ONE_DAY = 24 * ONE_HOUR

local launcher_params = {
  isolated = config.isolated,
  reload = config.reload,
  period = config.period or ONE_HOUR,
  ttl = config.ttl or ONE_DAY
}

config.rules = config.rules or {}

local function addrule(rule)
  config.rules[#config.rules+1] = rule
end

addrule{ -- URI remapping example
  match = "^/$",
  with = redirecthandler,
  params = {"index.html"}
}

addrule{ -- wsapihandler example
  match = {"%.lua$", "%.lua/" },
  with = wsx.makeGenericHandler (config.docroot, launcher_params)
}

addrule{ -- wsapihandler example
  match = {"%.ws$", "%.ws/" },
  with = wsx.makeGenericHandler (config.docroot, launcher_params)
}

if opts.cgilua then
  local hcgi = require "xavante.cgiluahandler"
  addrule{
    match = {"%.lp$", "%.lp/.*$", "%.cgi$", "%.cgi/.*$" },
    with = hcgi.makeHandler (config.docroot, launcher_params)
  }
end
if opts.op then
  local hop = require "orbit.ophandler"
  addrule{
    match = {"%.op$", "%.op/.*$" },
    with = hop.makeHandler (config.docroot, launcher_params)
  }
end

addrule{ -- filehandler example
  match = ".",
  with = filehandler,
  params = { baseDir = config.docroot }
}

-- Displays a message in the console with the used ports
xavante.start_message(config.start_message)

io.stdout:write("[Xavante launcher] Starting Xavante... ")

xavante.HTTP{
    server = {host = "*", port = config.port},

    defaultHost = {
        rules = config.rules
    },
}

res, err = pcall(xavante.start, function (...)
                                   io.stdout:flush()
                                   io.stderr:flush()
                                   return config.is_finished(...)
                                end, config.timeout)
if not res then
   io.stderr:write(err .. " ")
else
   io.stderr:write("[Xavante launcher] Xavante stopped ")
end
root@fqs:/usr/local/bin#

运行流程分析

1、 xavante 负责服务器的启动， 并制定 cgilua 请求处理的handler注册

   { -- cgiluahandler example
      match = {"%.lp$", "%.lp/.*$", "%.lua$", "%.lua/.*$" },
      with = xavante.cgiluahandler.makeHandler (webDir)
   },

2、xavante.cgiluahandler.makeHandler (webDir) ， handler的构造

-------------------------------------------------------------------------------
-- Returns the CGILua handler
-------------------------------------------------------------------------------
function _M.makeHandler (diskpath, params)
   params = setmetatable(params or {}, { __index = { modname = "wsapi.sapi",
      bootstrap = bootstrap } })
   local sapi_loader = common.make_isolated_launcher(params)
   return xavante.makeHandler(sapi_loader, nil, diskpath)
end

其中，handler构造依赖了 xavante的wsapi， with的值可以是 function(req, res)

local xavante = require "wsapi.xavante"  --- 专门针对  xavante写的wsapi的适配

-- Makes a WSAPI handler for a single WSAPI application
function _M.makeHandler (app_func, app_prefix, docroot, app_path, extra_vars)
  return function (req, res)
    return wsapihandler(req, res, app_func, app_prefix, docroot, app_path, extra_vars)
  end
end

wsapi.xavante中存在 构造 cgivars 表。

make_handler 入参 wsapi_loader需要 wsapi.sapi文件支持

   params = setmetatable(params or {}, { __index = { modname = "wsapi.sapi",
      bootstrap = bootstrap } })
   local sapi_loader = common.make_isolated_launcher(params)

此loader即加载 wsapi.sapi文件， 文件被rings包裹运行， 即 wsapi.sapi –> cgilua 都是在独立环境下运行

前面 “wsapi.xavante中存在 构造 cgivars 表” 也会传入 独立的运行环境。

wsapi.sapi 直接 调用 cgilua

  local cgilua = require "cgilua"
  cgilua.main()
  return res:finish()
end

WSAPI Xavante 安装后自带 wsapi.cgi 程序

root@fqs:/usr/local/bin# ls
cgilua.cgi  cgilua.fcgi  summary.lua  wsapi  wsapi.cgi
root@fqs:/usr/local/bin#
root@fqs:/usr/local/bin#
root@fqs:/usr/local/bin# cat wsapi.cgi
#!/bin/sh

exec '/usr/bin/lua5.1' -e 'package.path="/root/.luarocks/share/lua/5.1/?.lua;/root/.luarocks/share/lua/5.1/?/init.lua;/usr/local/share/lua/5.1/?.lua;/usr/local/share/lua/5.1/?/init.lua;"..package.path; package.cpath="/root/.luarocks/lib/lua/5.1/?.so;/usr/local/lib/lua/5.1/?.so;"..package.cpath' -e 'local k,l,_=pcall(require,"luarocks.loader") _=k and l.add_context("wsapi","1.6.1-1")' '/usr/local/lib/luarocks/rocks/wsapi/1.6.1-1/bin/wsapi.cgi' "$@"
root@fqs:/usr/local/bin#

实现文件：

root@fqs:/usr/local/bin# cat /usr/local/lib/luarocks/rocks/wsapi/1.6.1-1/bin/wsapi.cgi
#!/usr/bin/lua

-- Generic WSAPI CGI launcher, extracts application to launch
-- either from the command line (use #!wsapi in the script)
-- or from SCRIPT_FILENAME/PATH_TRANSLATED

local wsapi = require "wsapi"
local common = require "wsapi.common"
local cgi = require "wsapi.cgi"

local arg_filename = (...)

local function wsapi_loader(wsapi_env)
  local path, file, modname, ext =
      common.find_module(wsapi_env, arg_filename, "wsapi.cgi", { "SCRIPT_FILENAME", "PATH_TRANSLATED" })
  if not path then
    error({ 404, "Resource " .. wsapi_env.SCRIPT_NAME .. " not found" })
  end
  wsapi.app_path = path
  local app = common.load_wsapi(path, file, modname, ext)
  wsapi_env.APP_PATH = path
  return app(wsapi_env)
end

cgi.run(wsapi_loader)
root@fqs:/usr/local/bin#

此cgi程序用于运行 满足 wsapi接口的应用脚本， 例如：

http://keplerproject.github.io/wsapi/manual.html

#!/usr/bin/env wsapi.cgi

module(..., package.seeall)

function run(wsapi_env)
  local headers = { ["Content-type"] = "text/html" }

  local function hello_text()
    coroutine.yield("<html><body>")
    coroutine.yield("<p>Hello Wsapi!</p>")
    coroutine.yield("<p>PATH_INFO: " .. wsapi_env.PATH_INFO .. "</p>")
    coroutine.yield("<p>SCRIPT_NAME: " .. wsapi_env.SCRIPT_NAME .. "</p>")
    coroutine.yield("</body></html>")
  end

  return 200, headers, coroutine.wrap(hello_text)
end