Send OTA updates to remotely update lua scripts on your ESP8266.

ota.lua

-- Send OTA updates to remotely update lua scripts on your ESP8266.
--
-- LICENCE: http://opensource.org/licenses/MIT
-- Created by Jude Pereira <contact@judepereira.com>
-- See https://judepereira.com/blog/sending-ota-updates-over-wifi-to-your-esp8266/

srv = net.createServer(net.TCP)

current_file_name = nil

srv:listen(8080, function(conn)
    conn:on("receive", function(sck, payload)
        if string.sub(payload, 1, 5) == "BEGIN" then
            current_file_name = string.sub(payload, 7)
            file.open(current_file_name, "w")
            file.close()
            sck:send("NodeMCU: Writing to " .. current_file_name .. '...\n')
        elseif string.sub(payload, 1, 4) == "DONE" then
            sck:send("NodeMCU: Wrote file " .. current_file_name .. "!\n")
            current_file_name = nil
        elseif string.sub(payload, 1, 7) == "RESTART" then
            sck:send("NodeMCU: Restart!\n")
            tmr.create():alarm(500, tmr.ALARM_SINGLE, node.restart)
        else
            if file.open(current_file_name, "a+") then
                if file.write(payload) then
                    file.close()
                    sck:send("ok\n")
                else
                    sck:send("NodeMCU: Write failed!\n")
                end
            else
                sck:send("NodeMCU: Open failed!\n")
            end
        end
    end)
    conn:on("sent", function(sck) sck:close() end)
end)