first question + junior dev here !

So my problem is : I'm developping an API whith nodejs/express + Docker and Multer where I want to upload files. I tried to configure Docker as good as I can, same for Multer and persist uploaded files in a volume but it keeps throwing me this error :

{
    "errno": -13,
    "code": "EACCES",
    "syscall": "open",
    "path": "public/media/pictures/picture-1642414319690.jpg",
    "storageErrors": []
}

Here is my Multer upload middleware config :

const multer = require('multer');
const path = require('path');

// PICTURES
// Picture storage path
const storage = multer.diskStorage({
  destination(req, file, cb) {
    cb(null, '/public/media/pictures');
  },
  filename: (req, file, cb) => {
    cb(
      null,
      `${file.fieldname}-${Date.now()}${path.extname(file.originalname)}`
    );
  },
});
// Check pictures type
const checkPicType = (file, cb) => {
  // Allowed ext
  const pictypes = /jpeg|jpg|png/;
  // Check ext
  const extname = pictypes.test(path.extname(file.originalname).toLowerCase());
  // Check mime
  const mimetype = pictypes.test(file.mimetype);

  if (mimetype && extname) {
    return cb(null, true);
  }
  return cb('Error: Images only!');
};
// Picture upload options
const picUpload = multer({
  storage,
  limits: {
    fields: 5,
    fieldNameSize: 10,
    fieldSize: 2000,
    fileSize: 25000000,
  },
  fileFilter(req, file, cb) {
    checkPicType(file, cb);
  },
}).single('picture');

module.exports = {
  picUpload,
};

My Upload method in api/picture.js :

router.post('/upload', (req, res) => {
  picUpload(req, res, (err) => {
    if (err) {
      return res.status(403).json(err);
    }
    return res.status(201).json({
      path: `${req.protocol}://${req.hostname}:${PORT}/${req.file.path}`,
    });
  });
});

and finally my docker-compose :

services:
  web:
      build:
        context: ./
        target: dev
      volumes:
        - .:/src
        - uploaded-files:/src/public/media/files
        - uploaded-pictures:/src/public/media/pictures
      command: npm run start:dev
      ports:
        - "5000:5000"
      environment:
        NODE_ENV: development
        DEBUG: nodejs-docker-express:*
  postgres:
    image: postgres
    restart: always
    environment:
      - POSTGRES_USER=${DB_USER}
      - POSTGRES_PASSWORD=${DB_PASS}
    volumes:
      - postgres:/var/lib/postgresql/data
    ports:
      - '5432:5432'

volumes:
    postgres:
    uploaded-files:
    uploaded-pictures:

As I said I'm pretty to docker and multer so if I missed a file or some lines to help you understand better, tell me.

Thanks!