Self-contained docker build with ARM64 publishing

.dockerignore

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+./out
+.bloop
+.bsp
+.metals
+.scala-build
+.scala
+gifs
+website
+.github
+Dockerfile

.github/workflows/publish-docker.yml

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+name: Create and publish a Docker image
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+on:
+  push:
+    branches: ["main"]
+    tags: ["v*"]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+  DOCKERFILE: ./Dockerfile
+  REGISTRY_LOGIN: ${{ github.actor }}
+  REGISTRY_PASSWORD: ${{ secrets.GITHUB_TOKEN }}
+
+jobs:
+  docker_build:
+    strategy:
+      fail-fast: true
+      matrix:
+        os: ["ubuntu-24.04", "ubuntu-24.04-arm"]
+    runs-on: ${{ matrix.os }}
+    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
+      #
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ env.REGISTRY_LOGIN }}
+          password: ${{ env.REGISTRY_PASSWORD }}
+
+      # This step uses [docker/metadata-action](https://github.com/docker/metadata-action#about) to extract tags and labels that will be applied to the specified image. The `id` "meta" allows the output of this step to be referenced in a subsequent step. The `images` value provides the base name for the tags and labels.
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      # This step uses the `docker/build-push-action` action to build the image, based on your repository's `Dockerfile`. If the build succeeds, it pushes the image to GitHub Packages.
+      # It uses the `context` parameter to define the build's context as the set of files located in the specified path. For more information, see "[Usage](https://github.com/docker/build-push-action#usage)" in the README of the `docker/build-push-action` repository.
+      # It uses the `tags` and `labels` parameters to tag and label the image with the output from the "meta" step.
+      - name: Build and push Docker image
+        id: push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ${{ env.DOCKERFILE }}
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-${{ matrix.os }}
+          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-${{ matrix.os }},mode=max
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+      # This step generates an artifact attestation for the image, which is an unforgeable statement about where and how it was built. It increases supply chain security for people who consume the image. For more information, see "[AUTOTITLE](/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds)."
+      - name: Generate artifact attestation
+        uses: actions/attest-build-provenance@v3
+        with:
+          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
+          subject-digest: ${{ steps.push.outputs.digest }}
+          push-to-registry: true
+
+      - name: Export digest
+        run: |
+          mkdir -p /tmp/digests
+          digest="${{ steps.push.outputs.digest }}"
+          touch "/tmp/digests/${digest#sha256:}"
+
+      - name: Upload digest
+        uses: actions/upload-artifact@v5
+        with:
+          name: digests-${{ matrix.os }}
+          path: /tmp/digests/*
+          if-no-files-found: error
+          retention-days: 1
+
+  docker_release_merge:
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
+    needs: [docker_build]
+    if: github.event_name != 'pull_request' && (startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main')
+    steps:
+      - name: Download digests
+        uses: actions/download-artifact@v6
+        with:
+          pattern: digests-*
+          path: /tmp/digests
+          merge-multiple: true
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ env.REGISTRY_LOGIN }}
+          password: ${{ env.REGISTRY_PASSWORD }}
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Create manifest list and push
+        working-directory: /tmp/digests
+        run: |
+          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf '${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@sha256:%s ' *)
+
+      - name: Inspect image
+        run: |
+          docker buildx imagetools inspect ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.meta.outputs.version }}

Dockerfile

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+FROM eclipse-temurin:17 as build
+RUN apt update && apt install build-essential libz-dev clang procps git -y
+WORKDIR /workdir
+COPY . .
+RUN ./mill -i copyTo --task 'cli[].base-image.nativeImage' --dest "./docker-out/scala-cli" 1>&2
+
+FROM debian:stable-slim
+RUN apt update && apt install build-essential libz-dev clang procps -y
+COPY --from=build /workdir/docker-out/scala-cli /usr/bin/scala-cli
+RUN \
+ echo "println(1)" | scala-cli -S 3 - -v -v -v && \
+ echo "println(1)" | scala-cli -S 2.13 - -v -v -v && \
+ echo "println(1)" | scala-cli -S 2.12 - -v -v -v
+RUN \
+ echo "println(1)" | scala-cli --power package --native _.sc --force && \
+ echo "println(1)" | scala-cli --power package --native-image _.sc --force
+
+ENTRYPOINT ["scala-cli"]