ci: updated docker for optimized build

Signed-off-by: Varun Raj <mailme@varunraj.in>

Dockerfile

@@ -1,20 +1,48 @@
-# docker/dev.Dockerfile
-FROM node:latest
+# Source: https://github.com/vercel/next.js/blob/canary/examples/with-docker/README.md
 
-WORKDIR /app/next-app
-
-COPY package.json ./
-COPY yarn.lock ./
-
-RUN yarn install
+# Install dependencies only when needed
+FROM node:18-alpine AS deps
+# Check https://github.com/nodejs/docker-node/tree/b4117f9333da4138b03a546ec926ef50a31506c3#nodealpine to understand why libc6-compat might be needed.
+RUN apk add --no-cache libc6-compat
+WORKDIR /app
+COPY package.json  ./
+RUN npm install --frozen-lockfile
 
+# Rebuild the source code only when needed
+FROM node:18-alpine AS builder
+WORKDIR /app
+COPY --from=deps /app/node_modules ./node_modules
 COPY . .
+RUN npm run build
 
-ENV NEXT_TELEMETRY_DISABLED=1
+# Production image, copy all the files and run next
+FROM node:18-alpine AS runner
+WORKDIR /app
 
-RUN yarn build
+ENV NODE_ENV=production
+
+RUN addgroup -g 1001 -S nodejs
+RUN adduser -S nextjs -u 1001
+
+# You only need to copy next.config.js if you are NOT using the default configuration
+# COPY --from=builder /app/next.config.js ./
+COPY --from=builder /app/public ./public
+COPY --from=builder /app/package.json ./package.json
+
+# Automatically leverage output traces to reduce image size 
+# https://nextjs.org/docs/advanced-features/output-file-tracing
+COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
+
+USER nextjs
 
 EXPOSE 3000
 
-# Set the command to run the application
-CMD ["yarn", "start", "-p", "3000", "-H", "0.0.0.0"]
+ENV PORT=3000
+
+# Next.js collects completely anonymous telemetry data about general usage.
+# Learn more here: https://nextjs.org/telemetry
+# Uncomment the following line in case you want to disable telemetry.
+ENV NEXT_TELEMETRY_DISABLED=1
+
+CMD ["npm", "run", "start"]

next.config.mjs

@@ -1,6 +1,7 @@
 /** @type {import('next').NextConfig} */
 const nextConfig = {
   reactStrictMode: false,
+  output: 'standalone'
 };
 
 export default nextConfig;

package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "dev": "next dev",
     "build": "next build",
-    "start": "next start",
+    "start": "next start -p ${PORT:=3000} -H ${HOST:=0.0.0.0}",
     "lint": "next lint"
   },
   "author": {