add docker release workflow

Author: wolfv

.github/workflows/docker.yml

@@ -0,0 +1,71 @@
+name: Build and Push Docker Images
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - main
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_PREFIX: ${{ github.repository }}
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    strategy:
+      matrix:
+        include:
+          - image: server
+            dockerfile: docker/Dockerfile.server
+            binary: rust-tessera
+          - image: witness
+            dockerfile: docker/Dockerfile.witness
+            binary: witness
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Container Registry
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels)
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-${{ matrix.image }}
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=sha,prefix=sha-
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ${{ matrix.dockerfile }}
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+          platforms: linux/amd64,linux/arm64

README.md

@@ -283,16 +283,43 @@ fly deploy
 
 ### Docker
 
-```dockerfile
-FROM rust:1.75-slim as builder
-WORKDIR /app
-COPY . .
-RUN cargo build --release
-
-FROM debian:bookworm-slim
-COPY --from=builder /app/target/release/rust-tessera /usr/local/bin/
-COPY --from=builder /app/target/release/witness /usr/local/bin/
-CMD ["rust-tessera"]
+Pre-built images are available from GitHub Container Registry:
+
+```bash
+# Log server (replace OWNER/REPO with your GitHub repository)
+docker pull ghcr.io/OWNER/REPO-server:latest
+
+# Witness
+docker pull ghcr.io/OWNER/REPO-witness:latest
+```
+
+Run the log server:
+
+```bash
+docker run -d \
+  -p 8080:8080 \
+  -v tessera-data:/data \
+  -e LOG_ORIGIN="my-transparency-log" \
+  -e LOG_PRIVATE_KEY="PRIVATE+KEY+..." \
+  ghcr.io/OWNER/REPO-server:latest
+```
+
+Run the witness:
+
+```bash
+docker run -d \
+  -p 8081:8081 \
+  -v witness-data:/data \
+  -e WITNESS_PRIVATE_KEY="PRIVATE+KEY+..." \
+  -e WITNESS_LOGS="my-transparency-log=my-transparency-log+xxxx+..." \
+  ghcr.io/OWNER/REPO-witness:latest
+```
+
+To build images locally:
+
+```bash
+docker build -f docker/Dockerfile.server -t rust-tessera-server .
+docker build -f docker/Dockerfile.witness -t rust-tessera-witness .
 ```
 
 ### Kubernetes