ci: deploy the verified local image

Build and test the Next.js application once with persistent BuildKit caches, smoke-test the immutable runtime image, and activate that same image through the shared production Docker daemon with serialized rollback-safe deployment.

.gitea/buildkitd.toml

@@ -0,0 +1,2 @@
+[worker.oci]
+  max-parallelism = 1

.gitea/workflows/ci-cd.yml

@@ -12,68 +12,80 @@ on:
 jobs:
   verify:
     name: Verify production build
-    runs-on: ubuntu-latest
+    if: gitea.event_name != 'pull_request' || gitea.event.pull_request.head.repo.full_name == gitea.repository
+    runs-on: portfolio-ci
     timeout-minutes: 15
-    steps:
-      - name: Check out repository
-        uses: actions/checkout@v4
-
-      - name: Set up Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: 22
-          cache: npm
-
-      - name: Install dependencies
-        run: |
-          npm ci \
-            --registry="https://package-mirror.liara.ir/repository/npm/" \
-            --replace-registry-host=registry.npmjs.org \
-            --include=optional
-
-      - name: Lint
-        run: npm run lint
-
-      - name: Type-check
-        run: npm run typecheck
-
-      - name: Build standalone Next.js application
-        run: npm run build
-
-      - name: Test standalone runtime
-        run: npm test
-
-      - name: Audit production dependencies
-        run: |
-          npm audit \
-            --registry="https://package-mirror.liara.ir/repository/npm/" \
-            --audit-level=high
-
-  deploy:
-    name: Deploy production
-    needs: verify
-    if: gitea.event_name == 'push' && gitea.ref == 'refs/heads/main'
-    runs-on: ubuntu-latest
-    timeout-minutes: 20
     env:
-      RELEASE_ID: ${{ gitea.sha }}
-      DEPLOY_HOST: ${{ secrets.DEPLOY_HOST }}
-      DEPLOY_USER: ${{ secrets.DEPLOY_USER }}
-      DEPLOY_PORT: ${{ secrets.DEPLOY_PORT }}
-      DEPLOY_PATH: ${{ secrets.DEPLOY_PATH }}
-      DEPLOY_KNOWN_HOSTS: ${{ secrets.DEPLOY_KNOWN_HOSTS }}
-      SSH_PRIVATE_KEY: ${{ secrets.DEPLOY_SSH_KEY }}
+      BUILDER_NAME: portfolio-builder
+      VERIFY_IMAGE: portfolio-verify:${{ gitea.sha }}
+      RUNTIME_IMAGE: amiirkhl-portfolio:${{ gitea.sha }}
+      NPM_REGISTRY: https://package-mirror.liara.ir/repository/npm/
     steps:
       - name: Check out repository
         uses: actions/checkout@v4
 
-      - name: Configure SSH
+      - name: Prepare persistent BuildKit builder
         shell: bash
+        run: |
+          set -Eeuo pipefail
+          if ! docker buildx inspect "$BUILDER_NAME" >/dev/null 2>&1; then
+            docker buildx create \
+              --name "$BUILDER_NAME" \
+              --driver docker-container \
+              --buildkitd-config .gitea/buildkitd.toml
+          fi
+          docker buildx use "$BUILDER_NAME"
+          docker buildx inspect --bootstrap
+
+      - name: Verify application once
+        shell: bash
+        run: |
+          set -Eeuo pipefail
+          docker buildx build \
+            --builder "$BUILDER_NAME" \
+            --target verification \
+            --build-arg "NPM_REGISTRY=$NPM_REGISTRY" \
+            --tag "$VERIFY_IMAGE" \
+            --load \
+            --progress plain \
+            .
+
+      - name: Audit dependencies
+        shell: bash
+        run: |
+          set -Eeuo pipefail
+          docker run --rm "$VERIFY_IMAGE" \
+            npm audit \
+              --registry="$NPM_REGISTRY" \
+              --audit-level=high
+
+      - name: Create immutable runtime image
+        shell: bash
+        run: |
+          set -Eeuo pipefail
+          docker buildx build \
+            --builder "$BUILDER_NAME" \
+            --target runtime \
+            --build-arg "NPM_REGISTRY=$NPM_REGISTRY" \
+            --tag "$RUNTIME_IMAGE" \
+            --load \
+            --progress plain \
+            .
+
+      - name: Smoke-test runtime image
+        shell: bash
+        run: bash scripts/smoke-container.sh "$RUNTIME_IMAGE"
+
+      - name: Configure deployment SSH
+        if: gitea.event_name == 'push' && gitea.ref == 'refs/heads/main'
+        shell: bash
+        env:
+          DEPLOY_HOST: ${{ secrets.DEPLOY_HOST }}
+          DEPLOY_KNOWN_HOSTS: ${{ secrets.DEPLOY_KNOWN_HOSTS }}
+          SSH_PRIVATE_KEY: ${{ secrets.DEPLOY_SSH_KEY }}
         run: |
           set -Eeuo pipefail
           : "${DEPLOY_HOST:?DEPLOY_HOST secret is required}"
-          : "${DEPLOY_USER:?DEPLOY_USER secret is required}"
-          : "${DEPLOY_PATH:?DEPLOY_PATH secret is required}"
           : "${DEPLOY_KNOWN_HOSTS:?DEPLOY_KNOWN_HOSTS secret is required}"
           : "${SSH_PRIVATE_KEY:?DEPLOY_SSH_KEY secret is required}"
 
@@ -83,41 +95,56 @@ jobs:
           printf '%s\n' "$DEPLOY_KNOWN_HOSTS" > "$HOME/.ssh/known_hosts"
           chmod 600 "$HOME/.ssh/known_hosts"
 
-      - name: Package release
-        shell: bash
-        run: |
-          set -Eeuo pipefail
-          git archive \
-            --format=tar.gz \
-            --output="$RUNNER_TEMP/portfolio-$RELEASE_ID.tar.gz" \
-            HEAD
-
-      - name: Upload and activate release
+      - name: Upload release manifest
+        if: gitea.event_name == 'push' && gitea.ref == 'refs/heads/main'
         shell: bash
+        env:
+          DEPLOY_HOST: ${{ secrets.DEPLOY_HOST }}
+          DEPLOY_PORT: ${{ secrets.DEPLOY_PORT }}
+          DEPLOY_USER: ${{ secrets.DEPLOY_USER }}
         run: |
           set -Eeuo pipefail
+          : "${DEPLOY_USER:?DEPLOY_USER secret is required}"
           DEPLOY_PORT="${DEPLOY_PORT:-22}"
-          remote_archive="/tmp/portfolio-$RELEASE_ID.tar.gz"
-          ssh_options=(
-            -i "$HOME/.ssh/deploy_key"
-            -o BatchMode=yes
-            -o StrictHostKeyChecking=yes
-            -p "$DEPLOY_PORT"
-          )
-
           scp \
             -i "$HOME/.ssh/deploy_key" \
             -o BatchMode=yes \
             -o StrictHostKeyChecking=yes \
             -P "$DEPLOY_PORT" \
-            "$RUNNER_TEMP/portfolio-$RELEASE_ID.tar.gz" \
-            "$DEPLOY_USER@$DEPLOY_HOST:$remote_archive"
+            compose.yaml \
+            "$DEPLOY_USER@$DEPLOY_HOST:/tmp/portfolio-${{ gitea.sha }}-compose.yaml"
 
+      - name: Activate verified image
+        if: gitea.event_name == 'push' && gitea.ref == 'refs/heads/main'
+        shell: bash
+        env:
+          DEPLOY_HOST: ${{ secrets.DEPLOY_HOST }}
+          DEPLOY_PATH: ${{ secrets.DEPLOY_PATH }}
+          DEPLOY_PORT: ${{ secrets.DEPLOY_PORT }}
+          DEPLOY_USER: ${{ secrets.DEPLOY_USER }}
+        run: |
+          set -Eeuo pipefail
+          : "${DEPLOY_PATH:?DEPLOY_PATH secret is required}"
+          DEPLOY_PORT="${DEPLOY_PORT:-22}"
+          remote_compose="/tmp/portfolio-${{ gitea.sha }}-compose.yaml"
           printf -v remote_command \
-            'bash -s -- %q %q %q' \
-            "$DEPLOY_PATH" "$RELEASE_ID" "$remote_archive"
+            'bash -s -- %q %q %q %q %q' \
+            "$DEPLOY_PATH" \
+            "${{ gitea.sha }}" \
+            "$RUNTIME_IMAGE" \
+            "${{ gitea.run_number }}" \
+            "$remote_compose"
 
-          ssh "${ssh_options[@]}" \
+          ssh \
+            -i "$HOME/.ssh/deploy_key" \
+            -o BatchMode=yes \
+            -o StrictHostKeyChecking=yes \
+            -p "$DEPLOY_PORT" \
             "$DEPLOY_USER@$DEPLOY_HOST" \
             "$remote_command" \
             < scripts/deploy-release.sh
+
+      - name: Remove temporary verification image
+        if: always()
+        shell: bash
+        run: docker image rm "$VERIFY_IMAGE" >/dev/null 2>&1 || true

DEPLOYMENT.md

@@ -1,20 +1,27 @@
 # Deployment
 
 The Gitea Actions workflow in `.gitea/workflows/ci-cd.yml` verifies every pull
-request and every push to `main`. A successful push to `main` is then deployed
-over SSH. The server builds the exact Git archive tested by CI, starts the
-Compose service, and waits for its container health check.
+request and every push to `main`. A successful push to `main` builds one
+verified Docker image on the shared host daemon, smoke-tests it, and activates
+that exact commit-tagged image over SSH without uploading source or rebuilding.
 
-Releases are stored in `<DEPLOY_PATH>/releases/<commit-sha>`. The `current`
+Release manifests are stored in `<DEPLOY_PATH>/releases/<commit-sha>`. Each
+manifest records the immutable image tag and Gitea run number. The `current`
 symlink is changed only after the new container is healthy. If startup fails,
-the deployment script automatically rebuilds and starts the previous release.
+the deployment script restarts the previous image without rebuilding it.
 
 ## Gitea Actions setup
 
-Enable **Repository Actions** in the repository settings and register a trusted
-Gitea Runner. The workflow uses the `ubuntu-latest` label; that runner image must
-provide Bash, Git, `tar`, OpenSSH (`ssh` and `scp`), and standard GNU utilities.
-Node.js 22 is installed by the workflow.
+Enable **Repository Actions** in the repository settings and register the
+dedicated trusted runner maintained in
+`https://git.amiirkhl.ir/amiirkhl/portfolio-gitea-runner`. The
+workflow uses the `portfolio-ci` label. Its reusable job image provides Node.js
+22, Bash, Git, OpenSSH, Docker CLI, Buildx, and Compose. Runner capacity remains
+one because Gitea, builds, and production share a 2-core/4-GB server.
+
+The runner and job container use the host Docker socket. Restrict the label to
+this trusted repository and disable Actions for fork pull requests. The workflow
+also skips pull requests whose head repository differs from this repository.
 
 After the first successful verification run, protect `main` in Gitea and make
 the **Verify production build** status check required. This prevents a pull
@@ -46,8 +53,9 @@ the protection against a man-in-the-middle attack.
 
 ## One-time server setup
 
-The server needs Docker Engine with the Compose v2 plugin. The deployment user
-must be able to run `docker` without an interactive password prompt.
+The server needs Docker Engine with the Compose v2 and Buildx plugins. The
+runner and deployment user must reach the same Docker daemon, and the deployment
+user must run `docker` without an interactive password prompt.
 
 Create the deployment root and the external network once:
 
@@ -88,9 +96,30 @@ optimizer-cache invalidation API.
 For an emergency manual deployment from a checkout on the server:
 
 ```sh
-docker compose --project-name portfolio up --detach --build --remove-orphans
+docker compose \
+  --project-name portfolio \
+  --file compose.yaml \
+  --file compose.build.yaml \
+  up --detach --build --remove-orphans
 ```
 
+This legacy path builds `amiirkhl-portfolio:latest` and is intentionally kept
+outside the normal CI deployment. Existing source-based release directories can
+still be started with their original Compose file during migration. Automatic
+rollback begins with the first successful image-based release because older
+release directories do not contain `release.env` image metadata.
+
+## Pipeline timing verification
+
+After migrating the runner, record one cold run and three normal source-change
+runs. Expand the **Set up job** and **Complete job** sections in Gitea when
+capturing the results. For each run, record checkout, verification build, audit,
+runtime image creation, smoke test, deployment health wait, and completion time.
+All three warm runs should finish below 180 seconds without OOM events or
+production health failures. If they do not, collect `docker stats`, `free -h`,
+`df -h`, `docker system df`, `docker buildx du --builder portfolio-builder`, and
+the runner logs before changing or removing any quality gate.
+
 Old versioned release directories are deliberately retained for rollback. They
 can be removed manually after a newer release has been proven stable; keep the
 directory referenced by the `current` symlink.

Dockerfile

@@ -1,37 +1,48 @@
-FROM node:22-alpine AS builder
+# syntax=docker/dockerfile:1.7
+
+FROM node:22-alpine AS dependencies
 
 WORKDIR /app
 
 ARG NPM_REGISTRY=https://package-mirror.liara.ir/repository/npm/
+ENV NEXT_TELEMETRY_DISABLED=1
 
 COPY package.json package-lock.json ./
-RUN npm ci \
-  --registry="${NPM_REGISTRY}" \
-  --replace-registry-host=registry.npmjs.org \
-  --include=optional
+RUN --mount=type=cache,id=portfolio-npm-node22,target=/root/.npm,sharing=locked \
+  npm ci \
+    --registry="${NPM_REGISTRY}" \
+    --replace-registry-host=registry.npmjs.org \
+    --include=optional
+
+FROM dependencies AS verification
 
 COPY . .
-RUN npm run build
+RUN npm run lint
+RUN npm run typecheck
+RUN --mount=type=cache,id=portfolio-next-node22,target=/app/.next/cache,sharing=locked \
+  npm run build
+RUN npm test
 
 FROM node:22-alpine AS runtime
 
 WORKDIR /app
 ENV NODE_ENV=production \
+    NEXT_TELEMETRY_DISABLED=1 \
     HOSTNAME=0.0.0.0 \
     PORT=3000
 
 RUN addgroup --system --gid 1001 nodejs \
   && adduser --system --uid 1001 nextjs
 
-COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
-COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
-COPY --from=builder --chown=nextjs:nodejs /app/public ./public
+COPY --from=verification --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=verification --chown=nextjs:nodejs /app/.next/static ./.next/static
+COPY --from=verification --chown=nextjs:nodejs /app/public ./public
 RUN mkdir -p .next/cache && chown -R nextjs:nodejs .next/cache
 
 USER nextjs
 EXPOSE 3000
 
-HEALTHCHECK --interval=30s --timeout=3s --start-period=10s --retries=3 \
-  CMD wget --no-verbose --tries=1 --spider http://127.0.0.1:3000/ || exit 1
+HEALTHCHECK --interval=2s --timeout=2s --start-period=3s --retries=30 \
+  CMD ["node", "-e", "fetch('http://127.0.0.1:3000/').then(r=>{if(!r.ok)process.exit(1)}).catch(()=>process.exit(1))"]
 
 CMD ["node", "server.js"]

compose.build.yaml

@@ -0,0 +1,7 @@
+services:
+  portfolio-app:
+    image: amiirkhl-portfolio:latest
+    build:
+      context: .
+      dockerfile: Dockerfile
+      target: runtime

compose.yaml

@@ -1,17 +1,20 @@
 services:
   portfolio-app:
-    image: amiirkhl-portfolio:latest
-    build:
-      context: .
-      dockerfile: Dockerfile
+    image: ${PORTFOLIO_IMAGE:-amiirkhl-portfolio:latest}
     container_name: portfolio-app
     restart: unless-stopped
     healthcheck:
-      test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://127.0.0.1:3000/"]
-      interval: 30s
-      timeout: 3s
-      start_period: 10s
-      retries: 3
+      test:
+        [
+          "CMD",
+          "node",
+          "-e",
+          "fetch('http://127.0.0.1:3000/').then(r=>{if(!r.ok)process.exit(1)}).catch(()=>process.exit(1))",
+        ]
+      interval: 2s
+      timeout: 2s
+      start_period: 3s
+      retries: 30
     volumes:
       - next-image-cache:/app/.next/cache
     networks:

scripts/deploy-release.sh

@@ -3,20 +3,32 @@ set -Eeuo pipefail
 
 deploy_root="${1:?deployment root is required}"
 release_id="${2:?release id is required}"
-archive="${3:?release archive is required}"
+image="${3:?runtime image is required}"
+sequence="${4:?deployment sequence is required}"
+incoming_compose="${5:?incoming Compose file is required}"
 
 if [[ "$deploy_root" != /* || "$deploy_root" == "/" ]]; then
   echo "DEPLOY_PATH must be an absolute directory other than /." >&2
   exit 2
 fi
-
 if [[ ! "$release_id" =~ ^[0-9a-f]{7,64}$ ]]; then
   echo "The release id must be a Git commit SHA." >&2
   exit 2
 fi
-
-if [[ ! -f "$archive" ]]; then
-  echo "Release archive not found: $archive" >&2
+if [[ "$image" != "amiirkhl-portfolio:$release_id" ]]; then
+  echo "The runtime image must be tagged with the release id." >&2
+  exit 2
+fi
+if [[ ! "$sequence" =~ ^[1-9][0-9]*$ ]]; then
+  echo "The deployment sequence must be a positive integer." >&2
+  exit 2
+fi
+if [[ ! -f "$incoming_compose" ]]; then
+  echo "Incoming Compose file not found: $incoming_compose" >&2
+  exit 2
+fi
+if ! command -v flock >/dev/null 2>&1; then
+  echo "flock is required to serialize deployments." >&2
   exit 2
 fi
 
@@ -26,7 +38,7 @@ current_link="$deploy_root/current"
 staging_dir="$releases_dir/.incoming-$release_id-$$"
 
 cleanup() {
-  rm -f -- "$archive"
+  rm -f -- "$incoming_compose"
   if [[ -d "$staging_dir" ]]; then
     rm -rf -- "$staging_dir"
   fi
@@ -34,16 +46,12 @@ cleanup() {
 trap cleanup EXIT
 
 mkdir -p -- "$releases_dir"
+exec 9>"$deploy_root/.deploy.lock"
+flock -x 9
 
-if [[ ! -d "$release_dir" ]]; then
-  mkdir -- "$staging_dir"
-  tar -xzf "$archive" -C "$staging_dir"
-  mv -- "$staging_dir" "$release_dir"
-fi
-
-if [[ ! -f "$release_dir/compose.yaml" ]]; then
-  echo "The release does not contain compose.yaml." >&2
-  exit 2
+if ! docker image inspect "$image" >/dev/null 2>&1; then
+  echo "Verified runtime image is missing from the production Docker daemon: $image" >&2
+  exit 1
 fi
 
 previous_release=""
@@ -51,12 +59,41 @@ if [[ -L "$current_link" ]]; then
   previous_release="$(readlink -f -- "$current_link" || true)"
 fi
 
+if [[ -n "$previous_release" && -f "$previous_release/release.env" ]]; then
+  current_sequence="$(sed -n 's/^DEPLOY_SEQUENCE=//p' "$previous_release/release.env")"
+  current_release="$(basename "$previous_release")"
+  if [[ "$current_release" == "$release_id" ]]; then
+    echo "Release is already active: $release_id"
+    exit 0
+  fi
+  if [[ "$current_sequence" =~ ^[1-9][0-9]*$ ]] && (( sequence <= current_sequence )); then
+    echo "Refusing stale deployment sequence $sequence; current sequence is $current_sequence." >&2
+    exit 1
+  fi
+fi
+
+if [[ ! -d "$release_dir" ]]; then
+  mkdir -- "$staging_dir"
+  install -m 600 "$incoming_compose" "$staging_dir/compose.yaml"
+  {
+    printf 'PORTFOLIO_IMAGE=%s\n' "$image"
+    printf 'DEPLOY_SEQUENCE=%s\n' "$sequence"
+  } > "$staging_dir/release.env"
+  mv -- "$staging_dir" "$release_dir"
+fi
+
+if [[ ! -f "$release_dir/compose.yaml" || ! -f "$release_dir/release.env" ]]; then
+  echo "Release metadata is incomplete: $release_dir" >&2
+  exit 2
+fi
+
 compose() {
   local directory="$1"
   shift
   docker compose \
     --project-name portfolio \
     --file "$directory/compose.yaml" \
+    --env-file "$directory/release.env" \
     "$@"
 }
 
@@ -73,7 +110,7 @@ wait_until_healthy() {
   for _ in {1..30}; do
     status="$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' "$container_id")"
     case "$status" in
-      healthy|running)
+      healthy)
         return 0
         ;;
       unhealthy|exited|dead)
@@ -88,27 +125,35 @@ wait_until_healthy() {
   return 1
 }
 
-deploy() {
+activate() {
   local directory="$1"
+  local release_image
+
+  release_image="$(sed -n 's/^PORTFOLIO_IMAGE=//p' "$directory/release.env")"
+  if [[ -z "$release_image" ]] || ! docker image inspect "$release_image" >/dev/null 2>&1; then
+    echo "Release image is unavailable: ${release_image:-<unset>}" >&2
+    return 1
+  fi
+
   compose "$directory" config --quiet
-  compose "$directory" up --detach --build --remove-orphans
+  compose "$directory" up --detach --no-build --pull never --remove-orphans
   wait_until_healthy "$directory"
 }
 
-if deploy "$release_dir"; then
+if activate "$release_dir"; then
   new_link="$deploy_root/.current-$release_id-$$"
   ln -s -- "$release_dir" "$new_link"
   mv -Tf -- "$new_link" "$current_link"
-  echo "Deployment succeeded: $release_id"
+  echo "Deployment succeeded: $release_id ($image)"
   exit 0
 fi
 
 echo "Deployment failed; attempting rollback." >&2
-if [[ -n "$previous_release" && -f "$previous_release/compose.yaml" ]]; then
-  deploy "$previous_release"
+if [[ -n "$previous_release" && -f "$previous_release/compose.yaml" && -f "$previous_release/release.env" ]]; then
+  activate "$previous_release"
   echo "Rollback succeeded: $(basename "$previous_release")" >&2
 else
-  echo "No previous release is available to roll back to." >&2
+  echo "No image-based previous release is available for automatic rollback." >&2
 fi
 
 exit 1

scripts/smoke-container.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+image="${1:?runtime image is required}"
+container_name="portfolio-smoke-${GITEA_RUN_ID:-$$}"
+
+cleanup() {
+  docker rm --force "$container_name" >/dev/null 2>&1 || true
+}
+trap cleanup EXIT
+
+cleanup
+docker run --detach --name "$container_name" "$image" >/dev/null
+
+for _ in {1..30}; do
+  status="$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' "$container_name")"
+  case "$status" in
+    healthy)
+      break
+      ;;
+    unhealthy|exited|dead)
+      docker logs "$container_name" >&2
+      exit 1
+      ;;
+  esac
+  sleep 2
+done
+
+if [[ "$(docker inspect --format '{{.State.Health.Status}}' "$container_name")" != "healthy" ]]; then
+  docker logs "$container_name" >&2
+  echo "Runtime image did not become healthy within 60 seconds." >&2
+  exit 1
+fi
+
+docker exec -i "$container_name" node <<'NODE'
+const origin = 'http://127.0.0.1:3000';
+
+async function expectOk(path, options) {
+  const response = await fetch(`${origin}${path}`, options);
+  if (!response.ok) throw new Error(`${path} returned ${response.status}`);
+  return response;
+}
+
+const english = await expectOk('/');
+await expectOk('/fa');
+await expectOk('/projects/interanet-solutions');
+await expectOk('/fa/projects/interanet-solutions');
+
+const html = await english.text();
+const staticAsset = html.match(/(?:src|href)="(\/_next\/static\/[^"?#]+)/)?.[1];
+if (!staticAsset) throw new Error('No built static asset was found in the home page.');
+await expectOk(staticAsset);
+
+const optimized = await expectOk(
+  '/_next/image?url=%2Fimages%2Favatar.png&w=256&q=75',
+  { headers: { Accept: 'image/webp' } },
+);
+const contentType = optimized.headers.get('content-type') ?? '';
+if (!/^image\/(?:webp|png)$/.test(contentType)) {
+  throw new Error(`Unexpected optimized image type: ${contentType}`);
+}
+if ((await optimized.arrayBuffer()).byteLength === 0) {
+  throw new Error('Optimized image response was empty.');
+}
+NODE

src/styles/globals.css

@@ -26,7 +26,7 @@ body {
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
   overflow-x: hidden;
-  transition: background-color 0.25s ease, color 0.25s ease;
+  transition: color 0.25s ease;
 }
 
 html[dir='rtl'] body {