lua-nginx-moduleで動くGyazoServer

gyazo-server.lua

local upload = require "resty.upload"

math.randomseed(ngx.time())
local function random_string(digit)
  local alphabet = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"}
  local result = ""
  repeat
    result = result .. alphabet[math.random(36)]
    digit = digit - 1
  until digit == 0
  return result
end

local function file_exists(name)
  file = io.open(name, "r")
  if file then io.close(file) return true else return false end
end

local form = upload:new(4096)
if not form then
  ngx.exit(400)
end

local file, file_name, ext
while true do
  local typ, res = form:read()
  if typ == "header" then
    ext = string.match(res[2], "filename=%\"%S-%.(%S-)%\"")
    if ext == "com" then ext = "png" end -- for gyazo
    if ext then
      repeat
        file_name = random_string(12) .. "." .. ext
      until not file_exists(file_name)
      file = io.open(ngx.var.document_root .. "/" .. file_name, "w")
    end
  elseif typ == "body" then
    if file then file:write(res) end
  elseif typ == "part_end" then
    if file then io.close(file) end
  elseif typ == "eof" then
    ngx.say(ngx.var.scheme .. "://" .. ngx.var.http_host ..  "/" .. file_name)
    ngx.exit(200)
    break
  end
end