Dockerized full-stack app with Fly.io

import { defineConfig } from '@tanstack/react-start/config'
import viteTsConfigPaths from 'vite-tsconfig-paths'
 
export default defineConfig({
  tsr: {
    appDirectory: 'src',
  },
  vite: {
    plugins: [
      // this is the plugin that enables path aliases
      viteTsConfigPaths({
        projects: ['./tsconfig.json'],
      }),
    ],
  },
 server: {
   preset: 'node-server', // <=== add this
 }
})

FROM node:20-slim as base
 
# Install dependencies only when needed
FROM base AS deps
WORKDIR /app
 
# Install dependencies based on the preferred package manager
COPY package.json pnpm-lock.yaml* ./
RUN npm install -g pnpm && pnpm install --frozen-lockfile
 
# Rebuild the source code only when needed
FROM base AS builder
WORKDIR /app
COPY --from=deps /app/node_modules ./node_modules
COPY . .
 
# Install pnpm in the builder stage
RUN npm install -g pnpm
 
# Build the application
RUN pnpm build
 
# Production image, copy all the files and run the server
FROM node:20-slim AS runner
WORKDIR /app
 
ENV NODE_ENV=production
 
# Create a non-root user
RUN addgroup --system --gid 1001 nodejs && \
    adduser --system --uid 1001 nodejs
 
# THIS IS OPTIONAL, ONLY IF YOU NEED ACCESS TO THE FILE-SYSTEM
# Create directory for writable files with proper permissions
RUN mkdir -p /app/data && \
    chown -R nodejs:nodejs /app/data
 
# Copy only necessary files
COPY --from=builder /app/.output ./.output
 
# Expose the port the app will run on
EXPOSE 3000
 
USER nodejs
 
# Start the Node.js server
CMD ["node", ".output/server/index.mjs"]

# See https://fly.io/docs/reference/configuration/ for information about how to use this file.
 
app = 'tanstack-react-app' # Replace with your app name
primary_region = 'lhr' # Replace with your preferred region
 
[build]
  dockerfile = 'Dockerfile'
 
[env]
  PORT = '3000'
 
[processes]
  app = 'node .output/server/index.mjs'
 
[http_service]
  internal_port = 3000
  force_https = true
  auto_stop_machines = 'stop'
  auto_start_machines = true
  min_machines_running = 0
  processes = ['app']
 
[[vm]]
  memory = '1gb'
  cpu_kind = 'shared'
  cpus = 1