FlashAir uploader is a script that iterates over all photos and movies saved on an SD card and uploads them to an HTTP endpoint. Uploaded files are renamed. A tiny node

0_upload.lua

-- FlashAir Lua script
-- Copy to 'Lua' folder on your SD card
-- Set as RUN_SCRIPT/SD_EVENT in your SD_WLAN/CONFIG file:
-- LUA_RUN_SCRIPT=/Lua/upload.lua
-- LUA_SD_EVENT=/Lua/upload.lua

local httpendpoint = 'http://192.168.1.13:3333/upload'
local folder = '/DCIM'

-- Recursively iterate through directories
function walk_directory(folder, extension)
  for file in lfs.dir(folder) do
    -- Not sure if this is necessary, but it keeps 'LUA : not enough memory' out of the log
    collectgarbage()

    -- Find file path and type
    local path = folder .. "/" .. file
    local attr = lfs.attributes(path)
    if attr.mode == "file" then
      handle_file(file, path, extension)
    elseif attr.mode == "directory" then
      walk_directory(path, extension)
    end
  end
end

-- Check file for upload, upload and rename it
function handle_file(file, path, extension)
  -- Find files not yet marked as "_SAVED"
  if string.sub(path, -4, -1) ~= extension then return end
  if string.sub(path, -10, -5) == "_SAVED" then return end

  -- Upload file to HTTP server
  local boundary = '--61141483716826'
  local contenttype = 'multipart/form-data; boundary=' .. boundary
  -- <!--WLANSDFILE--> will be replaced with file content
  local body = '--'.. boundary .. '\r\n'
   ..'Content-Disposition: form-data; name=\"file\"; filename=\"'..file ..'\"\r\n'
   ..'Content-Type: text/plain\r\n'
   ..'\r\n'
   ..'<!--WLANSDFILE-->\r\n'
   ..'--' .. boundary .. '--\r\n'

  -- Exclude size of placeholder
  local size = lfs.attributes(path, 'size') + string.len(body) - 17
  -- Execute request (returns response body, response code, response header)
  local b, c, h = fa.request {
    url = httpendpoint,
    method = 'POST',
    headers = {['Content-Length'] = tostring(size),
    ['Content-Type'] = contenttype},
    file = path,
    body = body
  }
  b, h = nil
  collectgarbage()
  if (c ~= 200) then return end

  -- Mark file as "_SAVED"
  fa.rename(path, string.sub(path, 0, -5) .. '_SAVED' .. string.sub(path, -4, -1))
end

-- Keep checking WLAN status until it is up or 30 seconds passed
for i = 1, 300 do
  -- Allow card to connect with WLAN
  sleep(100)

  -- Check if WLAN is up
  if fa.WlanLink() == 1 then
    -- Upload pictures first
    walk_directory(folder, '.JPG')
    -- Upload movies later, they are much larger and might fail
    walk_directory(folder, '.MOV')
    break
  end
end

1_server.js

/* File Receiver
 * Handles uploads from flashair.
 * Install dependencies with npm using the package.json file: https://docs.npmjs.com/cli/install
 * Start with node: https://nodejs.org/en/
 */

var util = require('util')
var spawn = require('child_process').spawn;
var http = require('http');
var formidable = require('formidable');
var fs = require('fs');
var winston = require('winston');

var uploadPath = '/media/main/Bilder/FlashAir/';

// Create log file
winston.add(winston.transports.File, { filename: '/home/pi/upload/winston.json' });

// Redirect all errors into log file
function errorHandler(err) {
  if(err) {
    winston.error(err);
    throw err;
  }
}

winston.info('Starting file receiver');

http.createServer(function (req, res) {
  // Handle upload requests
  if (req.url == '/upload') {
    winston.info('Upload request');

    var form = new formidable.IncomingForm();
    form.parse(req, function (err, fields, files) {
      // console.log(util.inspect(files, false, null));
      if(!files.file) {
        winston.error('No file in request');
        res.writeHead(400);
        res.end('No file in request');
        return;
      }
      
      var readStream = fs.createReadStream(files.file.path);
      var writeStream = fs.createWriteStream(uploadPath + files.file.name);

      winston.info('File uploaded to: ' + files.file.path)
      readStream.on('error', errorHandler);
      writeStream.on('error', errorHandler);
      readStream.on('close', function () {
        winston.info('File moved to destination with name: ' + files.file.name)
        res.end('Done');

        fs.unlink(files.file.path, function(err) {
          errorHandler(err);
          if(err) return;
          winston.info('Removed temporary file');
        });

        /* I run a backup and sort script at this point.
         * Feel free to uncomment this and insert your own.
        winston.info('Running backup and sorting');
        spawn('bash', [ '/home/pi/backup/backup.sh' ]);
        */
      });

      readStream.pipe(writeStream);
    });
  } else {
    // For other requests show a basic html upload form
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.write('<form action="upload" method="post" enctype="multipart/form-data">');
    res.write('<input type="file" name="file"><br>');
    res.write('<input type="submit">');
    res.write('</form>');
    return res.end();
  }

}).listen(3333);

2_package.json

{
  "name": "file_receiver",
  "version": "0.0.0",
  "description": "receive files uploaded by flashair",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "flo",
  "license": "ISC",
  "dependencies": {
    "formidable": "^1.1.1",
    "winston": "^2.3.1"
  }
}