feat(ci): add GitHub Actions workflow for Docker image publishing

.github/workflows/docker-publish.yml

@@ -0,0 +1,206 @@
+# Builds and publishes the simrun container image to GHCR on version tags.
+#
+# Pipeline:
+#   1. build   - build each architecture on its own native runner, push by digest
+#   2. merge   - stitch the per-arch digests into one multiplatform manifest and
+#                tag it with the release version (e.g. 0.4.0, 0.4, latest)
+#   3. sign    - Cosign keyless (OIDC) signature + Syft SBOM attestation
+#
+
+name: Publish Docker image
+
+on:
+  push:
+    tags: ["v*"]
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
+permissions:
+  contents: read
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build:
+    name: Build ${{ matrix.suffix }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - platform: linux/amd64
+            runner: ubuntu-24.04
+            suffix: amd64
+          - platform: linux/arm64
+            runner: ubuntu-24.04-arm
+            suffix: arm64
+    runs-on: ${{ matrix.runner }}
+    timeout-minutes: 60
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          persist-credentials: false
+
+      - name: Set image name lowercase
+        run: echo "IMAGE_NAME_LC=$(echo "${{ env.IMAGE_NAME }}" | tr '[:upper:]' '[:lower:]')" >> "${GITHUB_ENV}"
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0
+        with:
+          version: latest
+
+      - name: Log in to GHCR
+        uses: docker/login-action@650006c6eb7dba73a995cc03b0b2d7f5ca915bee # v4.2.0
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@80c7e94dd9b9319bd5eb7a0e0fe9291e23a2a2e9 # v6.1.0
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LC }}
+
+      - name: Build and push by digest
+        id: build
+        uses: docker/build-push-action@f9f3042f7e2789586610d6e8b85c8f03e5195baf # v7.2.0
+        with:
+          context: .
+          platforms: ${{ matrix.platform }}
+          build-args: |
+            version=${{ steps.meta.outputs.version }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha,scope=simrun-${{ matrix.suffix }}
+          cache-to: type=gha,mode=max,scope=simrun-${{ matrix.suffix }}
+          # push-by-digest expects a single image manifest per arch; the default
+          # provenance attestation adds an extra manifest that breaks the merge.
+          provenance: false
+          outputs: type=image,name=${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LC }},push-by-digest=true,name-canonical=true,push=true
+
+      - name: Export digest
+        run: |
+          mkdir -p /tmp/digests
+          digest="${{ steps.build.outputs.digest }}"
+          touch "/tmp/digests/${digest#sha256:}"
+
+      - name: Upload digest
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: digest-${{ matrix.suffix }}
+          path: /tmp/digests/*
+          if-no-files-found: error
+          retention-days: 1
+
+  merge:
+    name: Create manifest
+    needs: build
+    runs-on: ubuntu-24.04
+    timeout-minutes: 30
+    permissions:
+      contents: read
+      packages: write
+    outputs:
+      version: ${{ steps.meta.outputs.version }}
+      digest: ${{ steps.digest.outputs.digest }}
+
+    steps:
+      - name: Set image name lowercase
+        run: echo "IMAGE_NAME_LC=$(echo "${{ env.IMAGE_NAME }}" | tr '[:upper:]' '[:lower:]')" >> "${GITHUB_ENV}"
+
+      - name: Download digests
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          path: /tmp/digests
+          pattern: digest-*
+          merge-multiple: true
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0
+        with:
+          version: latest
+
+      - name: Log in to GHCR
+        uses: docker/login-action@650006c6eb7dba73a995cc03b0b2d7f5ca915bee # v4.2.0
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@80c7e94dd9b9319bd5eb7a0e0fe9291e23a2a2e9 # v6.1.0
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LC }}
+          # latest is applied automatically for semver tags (flavor latest=auto),
+          # so a workflow_dispatch from a branch will not move :latest.
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=sha
+
+      - 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 }}/${{ env.IMAGE_NAME_LC }}@sha256:%s ' *)
+
+      - name: Capture manifest digest
+        id: digest
+        run: |
+          tag=$(jq -r '.tags[0]' <<< "${DOCKER_METADATA_OUTPUT_JSON}")
+          digest=$(docker buildx imagetools inspect "${tag}" --format '{{json .Manifest.Digest}}' | tr -d '"')
+          echo "tag=${tag}" >> "${GITHUB_OUTPUT}"
+          echo "digest=${digest}" >> "${GITHUB_OUTPUT}"
+
+      - name: Inspect manifest
+        run: docker buildx imagetools inspect "${{ steps.digest.outputs.tag }}"
+
+  sign:
+    name: Sign and attest
+    needs: merge
+    runs-on: ubuntu-24.04
+    timeout-minutes: 30
+    permissions:
+      contents: read
+      packages: write
+      id-token: write
+
+    steps:
+      - name: Set image name lowercase
+        run: echo "IMAGE_NAME_LC=$(echo "${{ env.IMAGE_NAME }}" | tr '[:upper:]' '[:lower:]')" >> "${GITHUB_ENV}"
+
+      - name: Install Cosign
+        uses: sigstore/cosign-installer@6f9f17788090df1f26f669e9d70d6ae9567deba6 # v4.1.2
+
+      - name: Log in to GHCR
+        uses: docker/login-action@650006c6eb7dba73a995cc03b0b2d7f5ca915bee # v4.2.0
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Generate SBOM (Syft)
+        uses: anchore/sbom-action@e22c389904149dbc22b58101806040fa8d37a610 # v0.24.0
+        with:
+          image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LC }}@${{ needs.merge.outputs.digest }}
+          output-file: sbom.spdx.json
+
+      - name: Sign and attest
+        env:
+          COSIGN_EXPERIMENTAL: "1"
+        run: |
+          REF="${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LC }}@${{ needs.merge.outputs.digest }}"
+          cosign sign --yes --recursive --registry-referrers-mode oci-1-1 "${REF}"
+          cosign attest --yes --recursive --registry-referrers-mode oci-1-1 \
+            --predicate sbom.spdx.json --type spdxjson "${REF}"

Dockerfile

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1
 
 # --- Build stage ---
-FROM golang:1.25.10 AS builder
+FROM golang:1.25.11 AS builder
 
 WORKDIR /build
 
@@ -22,7 +22,8 @@ RUN rm -rf internal/web/frontend && \
 
 # Build the server binary with the embedded frontend
 ARG version=unknown
-RUN CGO_ENABLED=0 go build \
+RUN git config --global --add safe.directory /build && \
+    CGO_ENABLED=0 go build \
     -ldflags="-w -s \
       -X github.com/IBM/simrun/internal/version.Version=${version} \
       -X github.com/IBM/simrun/internal/version.Commit=$(git rev-parse --short HEAD 2>/dev/null || echo unknown) \

go.mod

@@ -1,6 +1,6 @@
 module github.com/IBM/simrun
 
-go 1.25.10
+go 1.25.11
 
 require (
 	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.1

mise.toml

@@ -1,5 +1,5 @@
 [tools]
-go = "1.25.10"
+go = "1.25.11"
 golangci-lint = "2.12.2"
 mockery = "3.5.5"
 node = "22"