update docker file and ignore

.dockerignore

@@ -1,3 +1,7 @@
+Dockerfile
+.dockerignore
 node_modules
 npm-debug.log
+README.md
 .next
+.git

Dockerfile

@@ -2,22 +2,46 @@
 # https://hub.docker.com/_/node
 FROM node:20-alpine
 
+# 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
+
 # Create and change to the app directory.
-WORKDIR /usr/src/app
+WORKDIR /app
+
+# Install dependencies based on the preferred package manager.
+COPY package.json yarn.lock* package-lock.json* pnpm-lock.yaml* ./
+RUN \
+  if [ -f yarn.lock ]; then yarn --frozen-lockfile; \
+  elif [ -f package-lock.json ]; then npm ci; \
+  elif [ -f pnpm-lock.yaml ]; then corepack enable pnpm && pnpm i --frozen-lockfile; \
+  else echo "Lockfile not found." && exit 1; \
+  fi
 
-# Copy application dependency manifests to the container image.
-# A wildcard is used to ensure both package.json AND package-lock.json are copied.
-# Copying this separately prevents re-running npm install on every code change.
-COPY package*.json ./
+# Install PM2.
+RUN npm install -g pm2
 
 # Install production dependencies.
 RUN npm ci
 
+# Set the user to non-root and create necessary directories.
+RUN addgroup --system --gid 1001 nodejs
+RUN adduser --system --uid 1001 nextjs
+
+# Change the ownership of the app directory to the nodejs user.
+RUN chown nextjs:nodejs /app
+
 # Copy local code to the container image.
 COPY . .
 
+# Set environment variables for production.
+ENV NEXT_TELEMETRY_DISABLED 1
+ENV PORT 3000
+
+# Expose the port the app runs on.
+EXPOSE 3000
+
 # Build the application for production.
 RUN npm run build
 
 # Run the web service on container startup.
-CMD [ "npm", "start" ]
+CMD ["pm2-runtime", "start", "npm", "--", "start"]