|
| 1 | +name: Get Repo Config and Image |
| 2 | +on: |
| 3 | + workflow_call: |
| 4 | + inputs: |
| 5 | + registry: |
| 6 | + required: false |
| 7 | + type: string |
| 8 | + default: ghcr.io |
| 9 | + namespace: |
| 10 | + required: false |
| 11 | + type: string |
| 12 | + default: nhsdigital/eps-devcontainers |
| 13 | + owner: |
| 14 | + required: false |
| 15 | + type: string |
| 16 | + default: NHSDigital |
| 17 | + verify_published_from_main_image: |
| 18 | + required: false |
| 19 | + type: boolean |
| 20 | + default: true |
| 21 | + predicate_type: |
| 22 | + required: false |
| 23 | + type: string |
| 24 | + default: https://slsa.dev/provenance/v1 |
| 25 | + outputs: |
| 26 | + tag_format: |
| 27 | + description: The tag format to be used for releases, as defined in .github/config/settings.yml |
| 28 | + value: ${{ jobs.get_config_values.outputs.tag_format }} |
| 29 | + devcontainer_image: |
| 30 | + description: The devcontainer image name as defined in .devcontainer/devcontainer.json |
| 31 | + value: ${{ jobs.get_config_values.outputs.devcontainer_image }} |
| 32 | + devcontainer_version: |
| 33 | + description: The devcontainer image version as defined in .devcontainer/devcontainer.json |
| 34 | + value: ${{ jobs.get_config_values.outputs.devcontainer_version }} |
| 35 | + pinned_image: |
| 36 | + description: Fully-qualified digest-pinned image reference |
| 37 | + value: ${{ jobs.verify_attestation.outputs.pinned_image }} |
| 38 | + resolved_digest: |
| 39 | + description: Resolved digest for the supplied image reference |
| 40 | + value: ${{ jobs.verify_attestation.outputs.resolved_digest }} |
| 41 | + |
| 42 | +jobs: |
| 43 | + get_config_values: |
| 44 | + runs-on: ubuntu-22.04 |
| 45 | + outputs: |
| 46 | + tag_format: ${{ steps.load-config.outputs.TAG_FORMAT }} |
| 47 | + devcontainer_version: ${{ steps.load-config.outputs.DEVCONTAINER_VERSION }} |
| 48 | + devcontainer_image: ${{ steps.load-config.outputs.DEVCONTAINER_IMAGE }} |
| 49 | + runtime_docker_image: ${{ steps.load-config.outputs.RUNTIME_DOCKER_IMAGE }} |
| 50 | + steps: |
| 51 | + - name: Checkout code |
| 52 | + uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd |
| 53 | + with: |
| 54 | + ref: ${{ env.BRANCH_NAME }} |
| 55 | + fetch-depth: 0 |
| 56 | + |
| 57 | + - name: Load config value |
| 58 | + id: load-config |
| 59 | + run: | |
| 60 | + TAG_FORMAT=$(yq '.TAG_FORMAT' .github/config/settings.yml) |
| 61 | + DEVCONTAINER_IMAGE=$(jq -r '.build.args.IMAGE_NAME' .devcontainer/devcontainer.json) |
| 62 | + DEVCONTAINER_VERSION=$(jq -r '.build.args.IMAGE_VERSION' .devcontainer/devcontainer.json) |
| 63 | + RUNTIME_DOCKER_IMAGE="${DEVCONTAINER_IMAGE}:githubactions-${DEVCONTAINER_VERSION}" |
| 64 | + { |
| 65 | + echo "TAG_FORMAT=$TAG_FORMAT" |
| 66 | + echo "DEVCONTAINER_IMAGE=$DEVCONTAINER_IMAGE" |
| 67 | + echo "DEVCONTAINER_VERSION=$DEVCONTAINER_VERSION" |
| 68 | + echo "RUNTIME_DOCKER_IMAGE=$RUNTIME_DOCKER_IMAGE" |
| 69 | + } >> "$GITHUB_OUTPUT" |
| 70 | +
|
| 71 | + verify_attestation: |
| 72 | + runs-on: ubuntu-22.04 |
| 73 | + needs: get_config_values |
| 74 | + permissions: |
| 75 | + contents: read |
| 76 | + packages: read |
| 77 | + attestations: read |
| 78 | + outputs: |
| 79 | + pinned_image: ${{ steps.resolve.outputs.pinned_image }} |
| 80 | + resolved_digest: ${{ steps.resolve.outputs.resolved_digest }} |
| 81 | + steps: |
| 82 | + - name: Login to github container registry |
| 83 | + if: startsWith(inputs.registry, 'ghcr.io') |
| 84 | + uses: docker/login-action@b45d80f862d83dbcd57f89517bcf500b2ab88fb2 |
| 85 | + with: |
| 86 | + registry: ghcr.io |
| 87 | + username: ${{ github.actor }} |
| 88 | + password: ${{ secrets.GITHUB_TOKEN }} |
| 89 | + |
| 90 | + - name: Resolve digest |
| 91 | + id: resolve |
| 92 | + shell: bash |
| 93 | + env: |
| 94 | + RUNTIME_DOCKER_IMAGE: ${{ needs.get_config_values.outputs.runtime_docker_image }} |
| 95 | + REGISTRY: ${{ inputs.registry }} |
| 96 | + NAMESPACE: ${{ inputs.namespace }} |
| 97 | + run: | |
| 98 | + set -euo pipefail |
| 99 | +
|
| 100 | + if [[ "$RUNTIME_DOCKER_IMAGE" == *"/"* ]]; then |
| 101 | + IMAGE_REF="$RUNTIME_DOCKER_IMAGE" |
| 102 | + else |
| 103 | + IMAGE_REF="${REGISTRY}/${NAMESPACE}/${RUNTIME_DOCKER_IMAGE}" |
| 104 | + fi |
| 105 | +
|
| 106 | + if [[ "$IMAGE_REF" == *@sha256:* ]]; then |
| 107 | + IMAGE_BASE="${IMAGE_REF%@*}" |
| 108 | + RESOLVED_DIGEST="${IMAGE_REF#*@}" |
| 109 | + else |
| 110 | + RESOLVED_DIGEST="" |
| 111 | + MAX_ATTEMPTS=5 |
| 112 | + for attempt in $(seq 1 "$MAX_ATTEMPTS"); do |
| 113 | + if OUTPUT="$(docker buildx imagetools inspect "$IMAGE_REF" 2>&1)"; then |
| 114 | + RESOLVED_DIGEST="$(awk '/^Digest:/ {print $2; exit}' <<< "$OUTPUT")" |
| 115 | + if [[ -n "$RESOLVED_DIGEST" ]]; then |
| 116 | + break |
| 117 | + fi |
| 118 | + echo "Digest not found in imagetools output (attempt ${attempt}/${MAX_ATTEMPTS})." >&2 |
| 119 | + else |
| 120 | + echo "Failed to inspect image ${IMAGE_REF} (attempt ${attempt}/${MAX_ATTEMPTS})." >&2 |
| 121 | + echo "$OUTPUT" >&2 |
| 122 | + fi |
| 123 | +
|
| 124 | + if [[ "$attempt" -lt "$MAX_ATTEMPTS" ]]; then |
| 125 | + sleep $((attempt * 2)) |
| 126 | + fi |
| 127 | + done |
| 128 | + IMAGE_BASE="${IMAGE_REF%:*}" |
| 129 | + fi |
| 130 | +
|
| 131 | + if [[ -z "$RESOLVED_DIGEST" ]]; then |
| 132 | + echo "Could not resolve digest for image: $IMAGE_REF" >&2 |
| 133 | + exit 1 |
| 134 | + fi |
| 135 | +
|
| 136 | + PINNED_IMAGE="${IMAGE_BASE}@${RESOLVED_DIGEST}" |
| 137 | + echo "resolved_digest=${RESOLVED_DIGEST}" >> "$GITHUB_OUTPUT" |
| 138 | + echo "pinned_image=${PINNED_IMAGE}" >> "$GITHUB_OUTPUT" |
| 139 | + echo "Resolved image reference: ${IMAGE_REF}" |
| 140 | + echo "Resolved digest: ${RESOLVED_DIGEST}" |
| 141 | + echo "Resolved image reference: ${PINNED_IMAGE}" |
| 142 | +
|
| 143 | + - name: Verify attestation |
| 144 | + shell: bash |
| 145 | + env: |
| 146 | + GH_TOKEN: ${{ github.token }} |
| 147 | + OWNER: ${{ inputs.owner }} |
| 148 | + VERIFY_PUBLISHED_FROM_MAIN_IMAGE: ${{ inputs.verify_published_from_main_image }} |
| 149 | + PREDICATE_TYPE: ${{ inputs.predicate_type }} |
| 150 | + PINNED_IMAGE: ${{ steps.resolve.outputs.pinned_image }} |
| 151 | + run: | |
| 152 | + set -euo pipefail |
| 153 | +
|
| 154 | + args=("oci://${PINNED_IMAGE}" "--owner" "$OWNER" "--predicate-type" "$PREDICATE_TYPE") |
| 155 | +
|
| 156 | + if [[ "$VERIFY_PUBLISHED_FROM_MAIN_IMAGE" == "true" ]]; then |
| 157 | + args+=("--source-ref" "refs/heads/main") |
| 158 | + fi |
| 159 | +
|
| 160 | +
|
| 161 | + GH_FORCE_TTY=120 gh attestation verify "${args[@]}" 2>&1 |
| 162 | + echo "Verified attestation for ${PINNED_IMAGE}" |
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