[patch] Harden verified image publication

.github/workflows/lint-test-build.yml

@@ -1,13 +1,23 @@
 name: build-push
 on:
+  pull_request:
   push:
+    branches:
+      - main
+    tags:
+      - "*"
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 jobs:
   lint-test:
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Set up Go
         uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
@@ -19,8 +29,14 @@ jobs:
         with:
           version: latest
 
-      - name: Install dependencies
-        run: go get .
+      - name: Validate workflow syntax
+        run: go run github.com/rhysd/actionlint/cmd/actionlint@v1.7.12
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Require tidy module metadata
+        run: go mod tidy -diff
 
       - run: go build
 
@@ -35,13 +51,67 @@ jobs:
         with:
           files: ./coverage.out
           fail_ci_if_error: false
-        env:
-          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+
+  image-check:
+    if: github.event_name == 'pull_request'
+    strategy:
+      fail-fast: false
+      matrix:
+        architecture:
+          - runner: ubuntu-24.04
+            platform: linux/amd64
+            suffix: amd64
+          - runner: ubuntu-24.04-arm
+            platform: linux/arm64
+            suffix: arm64
+    runs-on: ${{ matrix.architecture.runner }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
+
+      - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3
+
+      - name: Build native image without credentials
+        uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83 # v6
+        with:
+          context: .
+          load: true
+          platforms: ${{ matrix.architecture.platform }}
+          provenance: false
+          push: false
+          tags: lightsout:ci-${{ matrix.architecture.suffix }}
+
+      - name: Scan native image
+        uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
+        with:
+          image-ref: lightsout:ci-${{ matrix.architecture.suffix }}
+          format: table
+          exit-code: "1"
+          ignore-unfixed: true
+          severity: HIGH,CRITICAL
+          vuln-type: os,library
 
   run:
+    name: run
+    if: ${{ always() && github.event_name == 'pull_request' }}
+    needs: [lint-test, image-check]
+    permissions: {}
+    uses: libops/.github/.github/workflows/pr-status.yaml@057262171193c6d563e7b08ae93d0c4aebfce2bd # credential-free-required-status
+    with:
+      needs-json: ${{ toJSON(needs) }}
+
+  publish:
+    if: github.ref == 'refs/heads/main' || (github.event_name == 'push' && startsWith(github.ref, 'refs/tags/'))
     needs: [lint-test]
-    uses: libops/.github/.github/workflows/build-push-ghcr.yaml@d7f0ba06b4c8a1f8559892ea65a0b1af4d024dd3 # main
+    uses: libops/.github/.github/workflows/build-push.yaml@8e27d95846671a9e319f1900e86a488a1d4f39b3 # resilient-guarded-signed-image-publisher
+    with:
+      ref: ${{ github.sha }}
+      expected-main-sha: ${{ github.ref == 'refs/heads/main' && github.sha || '' }}
+      scan: true
+      sign: true
+      certificate-identity: https://github.com/libops/.github/.github/workflows/build-push.yaml@8e27d95846671a9e319f1900e86a488a1d4f39b3
     permissions:
       contents: read
       packages: write
-    secrets: inherit
+      id-token: write

Dockerfile

@@ -1,4 +1,4 @@
-FROM ghcr.io/libops/go1.25:main@sha256:f43c9b34f888d2ac53e87c8e061554f826b8eb580863d7b21fd787b6f0378f8f AS builder
+FROM golang:1.25.12-alpine@sha256:56961d79ea8129efddcc0b8643fd8a5416b4e6228cfd477e3fd61deb2672c587 AS builder
 
 SHELL ["/bin/ash", "-o", "pipefail", "-ex", "-c"]
 
@@ -13,10 +13,14 @@ COPY *.go ./
 RUN --mount=type=cache,target=/root/.cache/go-build \
     CGO_ENABLED=0 go build -ldflags="-s -w" -o /app/binary .
 
-FROM ghcr.io/libops/go1.25:main@sha256:f43c9b34f888d2ac53e87c8e061554f826b8eb580863d7b21fd787b6f0378f8f
+FROM alpine:3.24@sha256:28bd5fe8b56d1bd048e5babf5b10710ebe0bae67db86916198a6eec434943f8b
+
+RUN apk add --no-cache ca-certificates
 
 COPY --from=builder /app/binary /app/binary
 
+USER 65532:65532
+
 ENV \
     PORT=8808 \
     INACTIVITY_TIMEOUT=90 \
@@ -25,3 +29,5 @@ ENV \
     GCP_ZONE= \
     GCP_INSTANCE_NAME= \
     LIBOPS_KEEP_ONLINE=
+
+CMD ["/app/binary"]

ci/workflow_contract_test.go

@@ -0,0 +1,76 @@
+package ci
+
+import (
+	"os"
+	"strings"
+	"testing"
+)
+
+const sharedPublisherSHA = "8e27d95846671a9e319f1900e86a488a1d4f39b3"
+
+func TestImagePublicationWorkflowContract(t *testing.T) {
+	workflow, err := os.ReadFile("../.github/workflows/lint-test-build.yml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	contents := string(workflow)
+
+	required := []string{
+		"pull_request:",
+		"if: github.event_name == 'pull_request'",
+		"if: github.ref == 'refs/heads/main' || (github.event_name == 'push' && startsWith(github.ref, 'refs/tags/'))",
+		"Build native image without credentials",
+		"persist-credentials: false",
+		"go mod tidy -diff",
+		"libops/.github/.github/workflows/build-push.yaml@" + sharedPublisherSHA,
+		"ref: ${{ github.sha }}",
+		"expected-main-sha: ${{ github.ref == 'refs/heads/main' && github.sha || '' }}",
+		"scan: true",
+		"sign: true",
+		"certificate-identity: https://github.com/libops/.github/.github/workflows/build-push.yaml@" + sharedPublisherSHA,
+		"packages: write",
+		"id-token: write",
+	}
+	for _, value := range required {
+		if !strings.Contains(contents, value) {
+			t.Errorf("image workflow must contain %q", value)
+		}
+	}
+
+	forbidden := []string{
+		"build-push.yaml@main",
+		"build-push-ghcr.yaml",
+		"secrets: inherit",
+		"secrets.",
+		"docker-registry:",
+		"additional-gar-registry:",
+	}
+	for _, value := range forbidden {
+		if strings.Contains(contents, value) {
+			t.Errorf("image workflow must not contain %q", value)
+		}
+	}
+}
+
+func TestRuntimeImageContract(t *testing.T) {
+	dockerfile, err := os.ReadFile("../Dockerfile")
+	if err != nil {
+		t.Fatal(err)
+	}
+	contents := string(dockerfile)
+
+	for _, value := range []string{
+		"FROM golang:1.25.12-alpine@sha256:",
+		"FROM alpine:3.24@sha256:",
+		"USER 65532:65532",
+		`CMD ["/app/binary"]`,
+	} {
+		if !strings.Contains(contents, value) {
+			t.Errorf("Dockerfile must contain %q", value)
+		}
+	}
+
+	if strings.Contains(contents, "ghcr.io/libops/go") {
+		t.Error("Lightsout must not depend on a moving LibOps Go utility image")
+	}
+}