nginx-lua: upload to aws-s3

nginx_upload2s3.lua

local function signature(ngxctx, method, bucket, objectkey)
  local access_key = os.getenv('AWS_ACCESS_KEY_ID')
  local secret_key = os.getenv('AWS_SECRET_ACCESS_KEY')
  local date = ngxctx.http_time(ngxctx.time())
  local headers = ngxctx.req.get_headers()
  local s2s = method .. "\n"
  s2s = s2s .. (headers['content-md5'] or "")  .. "\n"
  s2s = s2s .. (headers['content-type'] or "") .. "\n"
  s2s = s2s .. date .. "\n"
  s2s = s2s .. "/" .. bucket .. "/" .. objectkey
  local auth = 'AWS '..access_key..':'..ngxctx.encode_base64(ngxctx.hmac_sha1(secret_key, s2s))
  return auth, date
end

local function header_join_with_crlf(header)
  local str = "", k, v
  for k,v in pairs(header) do
    str = str .. v .. "\r\n"
  end
  return str
end

-- @return client, err
local function connect(ngxctx, host, bucket, objectkey)
  local ok, err
  local obj = {}
  obj.clientsock, err = ngxctx.req.socket()
  if err then
    return nil, 'failed to get sock - ' .. err
  end
  obj.serversock = ngxctx.socket.tcp()
  ok, err = obj.serversock:connect(host, 80)
  if not ok then
    return nil, 'failed to connect: ' .. host..' - ' .. err
  end
  local path = bucket.."/"..objectkey
  obj.send_header = function(self)
                      local headers = ngxctx.req.get_headers()
                      local reqtype = headers['content-type'] or 'application/json'
                      local reqsize = headers['content-length'] or '0'
                      local header = {'PUT /'..path..' HTTP/1.0', 'Content-Type: '..reqtype, 'Content-Length: '..reqsize}
                      local auth , date = signature(ngxctx, 'PUT', bucket, objectkey)
                      table.insert(header, 'Authorization: '..auth)
                      table.insert(header, 'Date: '..date)
                      local bytes, err = self.serversock:send(header_join_with_crlf(header).."\r\n")
                      if err then
                        self.err = 'failed to send header - ' .. err
                        return nil
                      end
                      self.reqsize = reqsize
                      return true
                    end
  obj.send_body =   function(self)
                      local size = tonumber(self.reqsize)
                      while size>0 do
                        local rsize = 2048
                        if size<rsize then rsize=size end
                        local data, err, partial = self.clientsock:receive(rsize)
                        if err then
                          self.err = 'failed to receive request body - ' .. err
                          return nil
                        end
                        if not chunk then chunk = partial end
                        local bytes, err = self.serversock:send(data)
                        if err then
                          self.err = 'failed to send request body - ' .. err
                          return nil
                        end
                        size = size - rsize
                      end
                      return true
                    end
  obj.recv_header = function(self)
                      self.content_length = nil
                      while true do
                        local data, err, partial = self.serversock:receive()
                        if err then
                          self.err = 'failed to receive response - ' .. err
                          return nil
                        end
                        if not data then data = partial end
                        local m, err = ngxctx.re.match(data, "HTTP/1.[01] ([0-9]+)", "i")
                        if m then ngxctx.status = tonumber(m[1]) end
                        m, err = ngxctx.re.match(data, "content-type: (.+)", "i")
                        if m then ngxctx.header.content_type = m[1] end
                        m, err = ngxctx.re.match(data, "content-length: ([0-9]+)", "i")
                        if m then self.content_length = tonumber(m[1]) end
                        if data=="" then break end
                      end
                      return true
                    end
  obj.recv_body =   function(self)
                      if self.content_length then
                        local data, err, partial = self.serversock:receive(self.content_length)
                        if err then
                          self.err = 'failed to receive response - ' .. err
                          return nil
                        end
                        if not data then data = partial end
                        ngxctx.header.content_length = #data
                        ngxctx.say(data)
                      end
                      return true
                    end
  obj.request = function(self)
                  local ok = self:send_header() and self:send_body() and self:recv_header() and self:recv_body()
                  self.serversock:close()
                  return ok
                end
  return obj
end

-- upload
local bucket    = ngx.var.bucket      -- s3 bucket name'
local objectkey = ngx.var.objectkey   -- s3 object key
local endpoint  = ngx.var.s3_endpoint -- s3 endpoint. ex: 's3-ap-northeast-1.amazonaws.com'
-- access_key = os.getenv('AWS_ACCESS_KEY_ID')
-- secret_key = os.getenv('AWS_SECRET_ACCESS_KEY')

local client, err = connect(ngx, endpoint, bucket, objectkey)
if err then
  ngx.log(ngx.ERR, err)
  return ngx.exit(500)
end
if not client:request() then
  ngx.log(ngx.ERR, client.err)
  return ngx.exit(500)
end