This is unrolled version of wsapi.fcgi, so the only dependency is `lfcgi`. Beware! Unlike WSAPI in this implementation call to app.run assumes that it returns a string as third parameter, not an iterator. I have renamed it to `body` from `res_iter`. Also there is MobDebug (something like analog of Zend XDebug) being included and logging to `wsap…

wsapi.fcgi

#!/usr/bin/env luajit

local jit = rawget(_G or _ENV, "jit")

--#if ENV ~= "PRODUCTION" then
jit.off(true, true)
--#end

if jit.arch == "x64" then
  package.cpath = package.cpath .. ";/usr/lib/x86_64-linux-gnu/lua/5.1/?.so"
elseif jit.arch == "x86" then
  package.cpath = package.cpath .. ";/usr/lib/i386-linux-gnu/lua/5.1/?.so"
end

-- Here is unrolled version of wsapi.fcgi launcher
local lfcgi = require("lfcgi")
local os = require("os")
local io = require("io")
local ipairs, pairs, type, assert = ipairs, pairs, type, assert
--#if ENV ~= "PRODUCTION" then
local collect_all_garbage = require("lua-nucleo/misc").collect_all_garbage
--#end

io.stdout = lfcgi.stdout
io.stderr = lfcgi.stderr
io.stdin = lfcgi.stdin

local app = require("index")
local mobdebug
if app.MOB_DEBUG then
  mobdebug = require("mobdebug")
end

local fcgi_loop = function(app, wsapi_log)
  -- HTTP status codes
  local status_codes = {
    [100] = "Continue",
    [101] = "Switching Protocols",
    [200] = "OK",
    [201] = "Created",
    [202] = "Accepted",
    [203] = "Non-Authoritative Information",
    [204] = "No Content",
    [205] = "Reset Content",
    [206] = "Partial Content",
    [300] = "Multiple Choices",
    [301] = "Moved Permanently",
    [302] = "Found",
    [303] = "See Other",
    [304] = "Not Modified",
    [305] = "Use Proxy",
    [307] = "Temporary Redirect",
    [400] = "Bad Request",
    [401] = "Unauthorized",
    [402] = "Payment Required",
    [403] = "Forbidden",
    [404] = "Not Found",
    [405] = "Method Not Allowed",
    [406] = "Not Acceptable",
    [407] = "Proxy Authentication Required",
    [408] = "Request Time-out",
    [409] = "Conflict",
    [410] = "Gone",
    [411] = "Length Required",
    [412] = "Precondition Failed",
    [413] = "Request Entity Too Large",
    [414] = "Request-URI Too Large",
    [415] = "Unsupported Media Type",
    [416] = "Requested range not satisfiable",
    [417] = "Expectation Failed",
    [500] = "Internal Server Error",
    [501] = "Not Implemented",
    [502] = "Bad Gateway",
    [503] = "Service Unavailable",
    [504] = "Gateway Time-out",
    [505] = "HTTP Version not supported",
  }

  -- Makes an index metamethod for the environment, from
  -- a function that returns the value of a server variable
  -- a metamethod lets us do "on-demand" loading of the WSAPI
  -- environment, and provides the invariant the the WSAPI
  -- environment returns the empty string instead of nil for
  -- variables that do not exist
  local mt_wsapi_env = {
    __index = function(self, n)
      local v = lfcgi.getenv(n) or os.getenv(n)
      self[n] = v or ""
      return v or ""
    end;
  }

  -- Runs an WSAPI application for each FastCGI request that comes
  -- from the FastCGI pipeline, until USR1 signal or other error happened
  while lfcgi.accept() >= 0 do
    --#if ENV ~= "PRODUCTION" then
    collect_all_garbage()
    --#end
    local time_request_start = os.clock()
    local memory_request_start = collectgarbage("count")

    -- Builds an WSAPI environment from the configuration table "t"
    local wsapi_env = { }
    setmetatable(wsapi_env, mt_wsapi_env)
    wsapi_env.input = { }
    wsapi_env.input.read = function(self, n)
      n = n or self.length or 0
      if n > 0 then
        return lfcgi.stdin:read(n)
      end
    end
    wsapi_env.input.length = tonumber(wsapi_env.CONTENT_LENGTH) or 0
    wsapi_env.error = lfcgi.stderr
    if wsapi_env.PATH_INFO == "" then wsapi_env.PATH_INFO = "/" end

    local os_exit
    if app.MOB_DEBUG and (app.MOB_DEBUG_ONLY_REMOTE_ADDR == nil or wsapi_env.REMOTE_ADDR == app.MOB_DEBUG_ONLY_REMOTE_ADDR) then
      os_exit = os.exit
      os.exit = mobdebug.done
      mobdebug.coro()
      mobdebug.start(wsapi_env.REMOTE_ADDR)
    end

    -- Runs an application with data from the configuration table "t",
    -- sending the WSAPI error/not found responses in case of errors
    local ok, status, headers, body = pcall(app.run, wsapi_env, wsapi_log)

    if not ok then
      -- In case of error the variable "status" contains error message
      body = status
      status = 500
      headers = {
        ["Content-Type"] = "text/html; charset=utf-8",
        ["Content-Length"] = #body,
      }
    end
    assert(type(body) == "string")

    -- Sends the complete response through the "out" pipe,
    -- using the provided write method
    assert(type(status) == "number" and status_codes[status] ~= nil)
    lfcgi.stdout:write("Status: " .. status .. " " .. status_codes[status] .. "\r\n")
    for h, v in pairs(headers or { }) do
       if type(v) ~= "table" then
          lfcgi.stdout:write(h .. ": " .. tostring(v) .. "\r\n")
       else
          for _, v in ipairs(v) do
             lfcgi.stdout:write(h .. ": " .. tostring(v) .. "\r\n")
          end
       end
    end
    lfcgi.stdout:write("\r\n")
    lfcgi.stdout:write(body)
    if lfcgi.stdout.flush then
      lfcgi.stdout:flush()
    end

    if app.MOB_DEBUG and (app.MOB_DEBUG_ONLY_REMOTE_ADDR == nil or wsapi_env.REMOTE_ADDR == app.MOB_DEBUG_ONLY_REMOTE_ADDR) then
      mobdebug.done()
      os.exit = os_exit
    end
  
    --#if ENV ~= "PRODUCTION" then
    collect_all_garbage()
    --#end
    wsapi_log:write(
        wsapi_env["REMOTE_ADDR"], " - ",
        wsapi_env["REMOTE_USER"] == "" and "-" or wsapi_env["REMOTE_USER"], " ",
        os.date("[%d/%b/%Y:%H:%M:%S +0000]"), " ",
        string.format('"%s %s %s"', wsapi_env["REQUEST_METHOD"], wsapi_env["REQUEST_URI"], wsapi_env["SERVER_PROTOCOL"]), " ",
        tostring(status), " ",
        string.format('"%s"', headers["Content-Type"]), " ",
        tostring(headers["Content-Length"]), " ",
        string.format('"%s"', wsapi_env["HTTP_REFERER"] == "" and "-" or wsapi_env["HTTP_REFERER"]), " ",
        string.format('"%s"', wsapi_env["HTTP_USER_AGENT"]), " ",
        --#if ENV ~= "PRODUCTION" then
        string.format("%.2fs", os.clock() - time_request_start), " ",
        string.format("%.2fKb", collectgarbage("count") - memory_request_start),
        --#end
        "\n"
      )
    wsapi_log:flush()
  end
end

local wsapi_log = io.open("../log/wsapi.log", "a")
local ok, err = xpcall(
    function()
      fcgi_loop(app, wsapi_log)
    end,
    function(err)
      return debug.traceback(err, 2)
    end
  )
if not ok then
  wsapi_log:write("ERROR:\n", err, "\n")
else
  wsapi_log:write("NOTE: Exited FastCGI loop nicely\n")
end
wsapi_log:close()