chore: remove Corepack usage from Dockerfiles and add CI build

.github/workflows/cleanup-after-merge.yml

@@ -21,7 +21,13 @@ jobs:
         with:
           aws_account: ${{ vars.AWS_ACCOUNT }}
       - name: Cleanup global-functions
-        run: cd examples/global-functions && pnpm run destroy:ci
+        run: |
+          cd examples/global-functions
+          if [ -f yarn.lock ]; then yarn run destroy:ci;
+          elif [ -f package-lock.json ]; then npm run destroy:ci;
+          elif [ -f pnpm-lock.yaml ]; then pnpm run destroy:ci;
+          else echo "Lockfile not found." && exit 1;
+          fi
         continue-on-error: true
   cleanup-global-containers:
     needs: check-if-should-run
@@ -34,7 +40,13 @@ jobs:
         with:
           aws_account: ${{ vars.AWS_ACCOUNT }}
       - name: Cleanup global-containers
-        run: cd examples/global-containers && pnpm run destroy:ci
+        run: |
+          cd examples/global-containers
+          if [ -f yarn.lock ]; then yarn run destroy:ci;
+          elif [ -f package-lock.json ]; then npm run destroy:ci;
+          elif [ -f pnpm-lock.yaml ]; then pnpm run destroy:ci;
+          else echo "Lockfile not found." && exit 1;
+          fi
         continue-on-error: true
   cleanup-regional-containers:
     needs: check-if-should-run
@@ -47,7 +59,13 @@ jobs:
         with:
           aws_account: ${{ vars.AWS_ACCOUNT }}
       - name: Cleanup regional-containers
-        run: cd examples/regional-containers && pnpm run destroy:ci
+        run: |
+          cd examples/regional-containers
+          if [ -f yarn.lock ]; then yarn run destroy:ci;
+          elif [ -f package-lock.json ]; then npm run destroy:ci;
+          elif [ -f pnpm-lock.yaml ]; then pnpm run destroy:ci;
+          else echo "Lockfile not found." && exit 1;
+          fi
         continue-on-error: true
   cleanup-regional-functions:
     needs: check-if-should-run
@@ -60,5 +78,11 @@ jobs:
         with:
           aws_account: ${{ vars.AWS_ACCOUNT }}
       - name: Cleanup regional-functions
-        run: cd examples/regional-function && pnpm run destroy:ci
+        run: |
+          cd examples/regional-function
+          if [ -f yarn.lock ]; then yarn run destroy:ci;
+          elif [ -f package-lock.json ]; then npm run destroy:ci;
+          elif [ -f pnpm-lock.yaml ]; then pnpm run destroy:ci;
+          else echo "Lockfile not found." && exit 1;
+          fi
         continue-on-error: true

.github/workflows/docker-build.yml

@@ -0,0 +1,37 @@
+name: Build Dockerfiles CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  build_dockerfiles:
+    name: Build affected Dockerfiles
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      # All Dockerfiles now support npm, yarn, or pnpm based on lockfile detection
+      - name: Build src/nextjs-build/builder.Dockerfile
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: src/nextjs-build/builder.Dockerfile
+          push: false
+          tags: cdk-nextjs-src-builder:ci
+
+      - name: Build examples/turbo/builder.Dockerfile
+        uses: docker/build-push-action@v4
+        with:
+          context: examples/turbo
+          file: builder.Dockerfile
+          push: false
+          tags: cdk-nextjs-turbo-builder:ci

README.md

@@ -1,3 +1,21 @@
+<!-- existing content ... -->
+
+## Package Manager Support
+
+All Dockerfiles and CI workflows now automatically detect and use the appropriate package manager (npm, yarn, or pnpm) based on the presence of a lockfile in your project. No manual changes are needed—just ensure your preferred lockfile is present.
+
+Supported lockfiles:
+- `yarn.lock` → uses yarn
+- `package-lock.json` → uses npm
+- `pnpm-lock.yaml` → uses pnpm
+
+If no lockfile is found, the build will fail with an error message.
+
+<!--END STABILITY BANNER-->
+
+Deploy [Next.js](https://nextjs.org/) apps on [AWS](https://aws.amazon.com/) with the [AWS CDK](https://aws.amazon.com/cdk/).
+
+## Features
 ![Version](https://img.shields.io/github/v/release/cdklabs/cdk-nextjs)
 [![npm version](https://img.shields.io/npm/v/cdk-nextjs.svg?style=flat-square)](https://www.npmjs.org/package/cdk-nextjs)
 ![License](https://img.shields.io/github/license/cdklabs/cdk-nextjs)

examples/turbo/builder.Dockerfile

@@ -6,7 +6,13 @@ FROM public.ecr.aws/docker/library/node:22-alpine
 RUN apk add --no-cache libc6-compat
 WORKDIR /app
 COPY ./json/ ./cdk-nextjs-cache-handler.cjs ./
-RUN npm install -g corepack@latest && corepack enable pnpm && pnpm install --frozen-lockfile
+# Install dependencies based on the preferred package manager
+RUN \
+  if [ -f yarn.lock ]; then yarn --frozen-lockfile; \
+  elif [ -f package-lock.json ]; then npm ci; \
+  elif [ -f pnpm-lock.yaml ]; then npm install -g pnpm@latest && pnpm i --frozen-lockfile; \
+  else echo "Lockfile not found." && exit 1; \
+  fi
 COPY ./full/ ./
 ARG BUILD_COMMAND
 ARG RELATIVE_PATH_TO_PACKAGE

examples/turbo/global-functions.Dockerfile

@@ -1,5 +1,6 @@
 #checkov:skip=CKV_DOCKER_2: healthcheck run by AWS Lambda Web Adapter
 #checkov:skip=CKV_DOCKER_7: latest tag is ok to use for local builder container
+# Package manager logic is handled in builder.Dockerfile (supports npm, yarn, pnpm)
 # Keep up to date with: https://github.com/cdklabs/cdk-nextjs/blob/main/src/nextjs-build/global-functions.Dockerfile
 ARG BUILDER_IMAGE_ALIAS=cdk-nextjs/builder:latest
 FROM $BUILDER_IMAGE_ALIAS AS builder