Add entrypoint to fix volume permissions at runtime

Dockerfile

@@ -30,26 +30,32 @@ RUN npm run build
 # This is the final, lean image that will be run
 FROM base AS production
 
-# Set a non-root user for security
+# Install 'su-exec' which is a lightweight tool for switching users
+RUN apk add --no-cache su-exec
+
+# Create a non-root user and group for security
 RUN addgroup -S appgroup && adduser -S appuser -G appgroup
 
-# Copy only the necessary files from the previous stages
+# Copy application files from the build stage
 COPY --from=build /usr/src/app/node_modules ./node_modules
 COPY --from=build /usr/src/app/views ./views
 COPY --from=build /usr/src/app/static ./static
 COPY --from=build /usr/src/app/lib ./lib
 COPY --from=build /usr/src/app/server.js .
 COPY --from=build /usr/src/app/config.json .
+COPY --from=build /usr/src/app/entrypoint.sh /usr/local/bin/entrypoint.sh
 
-# Create the data directory and set correct permissions
-# This is the FIX for the EACCES error
-RUN mkdir -p data && chown -R appuser:appgroup .
+# Ensure the entrypoint script is executable
+RUN chmod +x /usr/local/bin/entrypoint.sh
 
-# Switch to the non-root user
-USER appuser
+# Create the data directory. The entrypoint will fix its permissions at runtime.
+RUN mkdir -p data
+
+# Set the entrypoint to our script
+ENTRYPOINT ["entrypoint.sh"]
 
 # Expose the port the app runs on
 EXPOSE 8080
 
-# The command to start the application
+# The default command to start the application. This gets passed to the entrypoint.
 CMD [ "node", "server.js" ]