I am trying to containerize the front-end of my website and automate its deployment. My goal is to be able to have a new image be generated and hosted when a change is pushed, and have the server automatically fetch it and restart the container. Here are the steps that I am taking:

1. I create the image by first building my Node application and then bundling the distribution and nginx configuration files into the latest linuxserver/letsencrypt image. This is the Dockerfile:

   # Use the NodeJS image as builder
   FROM node:alpine AS builder
   
   # Create the workspace
   RUN mkdir -p /usr/src/app
   WORKDIR /usr/src/app
   
   # Copy the package file and source code
   COPY package.json /usr/src/app
   COPY . ./
   
   # Install dependencies
   RUN npm install
   
   # Build the application
   RUN npm run build
   
   # The nginx server, this builds the final image
   FROM linuxserver/letsencrypt
   
   # Copy the nginx configuration
   COPY ./config/nginx.conf /config
   
   # Copy the output of the builder
   COPY --from=builder /usr/src/app/dist /config/www
   
   # Inform Docker to listen on port 443 and 80
   EXPOSE 443 80  
   

2. This image is uploaded to GitHub's package registry and I poll for updates using Watchtower.

3. The image is started using this docker-compose file:

   version: "3"
   services:
     ...
     frontend:
       image: [IMAGE]
       container_name: frontend
       cap_add:
         - NET_ADMIN
       environment:
         - PUID=1000
         - PGID=1000
         - TZ=[TIMEZONE]
         - URL=[URL]
         - SUBDOMAINS=www,
         - VALIDATION=http
       ports:
         - 443:443
         - 80:80
       volumes:
         - ./frontend:/config
       restart: unless-stopped
     ...  
   

The issue is that the files that were packaged into the image using the COPY instruction are being overwritten when I use the following line in my docker-compose:

volumes:
  - ./frontend:/config  

If I remove that section from my docker-compose file everything works fine, however this is not a solution because that folder stores important data.

I have read that mounting a volume completely overwrites any previous data, however I like the fact that I can easily load the image onto my server and have all the required files already embedded. Is there anything that I can do to fix my issue, or am I misusing/misunderstanding docker images?

I have tried setting the volume to read only as suggested here, however this did not work and instead caused the image to continually stop and restart.

I have also briefly read about bind mounts and am wondering if they will be of any use.