chore(docker/ci): add nightly docker image builds (#3180)

Closes #3163

Adds a scheduled workflow to build nightly docker images for
`kona-node`, `kona-host`, and `kona-supervisor`.

Runs daily at 2 AM UTC, builds for both amd64 and arm64. Images are
pushed to ghcr.io with `nightly` and `nightly-YYYY-MM-DD` tags.

Can also be triggered manually via workflow_dispatch.

Author: ilikecodewithmyhand

.github/workflows/docker-nightly.yaml

@@ -0,0 +1,66 @@
+name: Build and Publish Nightly Docker Images
+
+on:
+  # Run nightly at 2 AM UTC
+  schedule:
+    - cron: '0 2 * * *'
+  # Allow manual trigger
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+
+env:
+  REGISTRY: ghcr.io
+  REGISTRY_IMAGE: ghcr.io/op-rs/kona
+
+jobs:
+  build-nightly:
+    name: Build Nightly Images
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        target: [kona-node, kona-host, kona-supervisor, kona-client]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Authenticate with container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Generate Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_IMAGE }}/${{ matrix.target }}
+          tags: |
+            type=raw,value=nightly
+            type=raw,value=nightly-{{date 'YYYY-MM-DD'}}
+
+      - name: Build and push multi-platform image
+        uses: docker/bake-action@v6
+        env:
+          BIN_TARGET: ${{ matrix.target }}
+          REPO_LOCATION: local
+          PLATFORMS: linux/amd64,linux/arm64
+        with:
+          files: |
+            ./docker/docker-bake.hcl
+            ${{ steps.meta.outputs.bake-file }}
+          targets: generic
+          push: true
+
+      - name: Display image info
+        run: |
+          echo "✅ Successfully built and pushed ${{ matrix.target }}"
+          echo "📦 Image: ${{ env.REGISTRY_IMAGE }}/${{ matrix.target }}:nightly"
+          echo "🏷️ Tags: ${{ steps.meta.outputs.tags }}"

docker/README.md

@@ -45,6 +45,32 @@ Create and activate a new builder and retry the bake command.
 docker buildx create --name kona-builder --use
 ```
 
+## Nightly Builds
+
+Nightly Docker images are automatically built and published every day at 2 AM UTC for:
+- `kona-node`
+- `kona-host`
+- `kona-supervisor`
+
+### Using Nightly Images
+
+```sh
+# Pull the latest nightly build (multi-platform: linux/amd64, linux/arm64)
+docker pull ghcr.io/op-rs/kona/kona-node:nightly
+docker pull ghcr.io/op-rs/kona/kona-host:nightly
+docker pull ghcr.io/op-rs/kona/kona-supervisor:nightly
+
+# Pull a specific date's nightly build
+docker pull ghcr.io/op-rs/kona/kona-node:nightly-2024-12-10
+```
+
+### Manual Trigger
+
+To manually trigger a nightly build:
+```sh
+gh workflow run "Build and Publish Nightly Docker Images"
+```
+
 ## Cutting a Release (for maintainers / forks)
 
 To cut a release of the docker image for any of the targets, cut a new annotated tag for the target like so: