docker 容器节点应用程序中的访问被拒绝问题

Question

I have a MERN stack application. I deployed the app on render cloud. I noticed that my image upload functionality is not working but works on local machine. I 'dockerized' the node application. The error message I got when I tried to upload image is this:

Error: EACCES: permission denied, open 'images/1666890887146download.png'

First, I am using multer npm package to handle image upload. The image is saved inside a folder called image in my api project folder. I think because of the user access in dockerfile, that is why the access is denied. Here is my dockerfile:

FROM  node:lts-alpine

 WORKDIR /app

 COPY package*.json ./

  COPY client/package*.json client/
  RUN npm run install-client --only=production


  COPY api/package*.json api/
  RUN npm run install-api --only=production



   COPY client/ client/
   RUN npm run client-build --prefix client


 COPY api/ api/



 USER node

 CMD [ "npm", "start", "--prefix", "api" ]



 EXPOSE 5000

Here is my multer image upload function:

 const ALLOWED_FORMATS = ['image/jpeg', 'image/png', 'image/jpg'];

    //login to upload images using libery called multer
    const storage = multer.diskStorage({//choosing destination of the file
    destination:(req, file, cb) =>{
    if(ALLOWED_FORMATS.includes(file.mimetype)){
         cb(null, "./images")
    }else{
        cb(new Error('Not supported file type!'), false)
    }
   
}, filename:(req, file,cb)=> {//choosing file name
   cb(null, req.body.name) 
  }
 });

 const upload = multer({storage:storage})

I am sensing that the node User I assigned in dockerfile does not have access to read and write file in the image folder. My logics rely on that because after uploading the image from the image folder to cloudinary, I also deleted it immediately. Is there a way I can assign node User the permission to read and write files in image folder? I am not too familiar with docker.

Answer 1

Yes, you can add the node user to the sudo group...

sudo usermod -aG sudo $USER

or you can give permissions to the user using something like

chown -R $USER:$USER images/