fix(cd): serialize gitea docker builds

.gitea/workflows/cd.yaml

@@ -204,6 +204,47 @@ jobs:
           username: ${{ secrets.HARBOR_USERNAME }}
           password: ${{ secrets.HARBOR_PASSWORD }}
 
+      # 2026-04-30 Codex: Gitea act-runner shares one Docker daemon across repos.
+      # When another repo starts a heavy docker build while AWOOOI Web is still
+      # building, the job container can disappear and Docker reports RWLayer=nil.
+      # A Docker-network lock is global to the host daemon and survives container
+      # namespaces, unlike /tmp/flock inside the transient job container.
+      - name: Acquire Docker Build Lock
+        run: |
+          LOCK_NAME="awoooi-cd-docker-build-lock"
+          STALE_SECONDS=7200
+          WAIT_ATTEMPTS=180
+
+          for attempt in $(seq 1 "$WAIT_ATTEMPTS"); do
+            if docker network create \
+              --label awoooi.ci-lock=docker-build \
+              --label awoooi.owner=cd-pipeline \
+              "$LOCK_NAME" >/dev/null 2>&1; then
+              echo "DOCKER_BUILD_LOCK=${LOCK_NAME}" >> "$GITHUB_ENV"
+              echo "✅ Docker build lock acquired: ${LOCK_NAME}"
+              exit 0
+            fi
+
+            CREATED_AT=$(docker network inspect "$LOCK_NAME" \
+              --format '{{.Created}}' 2>/dev/null || true)
+            if [ -n "$CREATED_AT" ]; then
+              CREATED_EPOCH=$(date -d "$CREATED_AT" +%s 2>/dev/null || echo 0)
+              NOW_EPOCH=$(date +%s)
+              if [ "$CREATED_EPOCH" -gt 0 ] && \
+                 [ $((NOW_EPOCH - CREATED_EPOCH)) -gt "$STALE_SECONDS" ]; then
+                echo "⚠️ stale Docker build lock detected, removing ${LOCK_NAME}"
+                docker network rm "$LOCK_NAME" >/dev/null 2>&1 || true
+                continue
+              fi
+            fi
+
+            echo "⏳ Docker build lock busy (attempt ${attempt}/${WAIT_ATTEMPTS}); waiting..."
+            sleep 10
+          done
+
+          echo "❌ timed out waiting for Docker build lock"
+          exit 1
+
       # ── API 鏡像建置（含 Layer Cache 加速）──────────────────────────────
       # 2026-04-01 ogt: CACHE_BUST=git_sha 確保 src/ 和 models.json 層每次重建
       # deps 層 (pip install) 仍可 cache → 加速；代碼/配置層強制失效
@@ -246,6 +287,16 @@ jobs:
           docker push ${{ env.HARBOR }}/awoooi/web:${{ github.sha }}
           docker push ${{ env.HARBOR }}/awoooi/web:latest
 
+      - name: Release Docker Build Lock
+        if: always()
+        run: |
+          if [ -n "${DOCKER_BUILD_LOCK:-}" ]; then
+            docker network rm "$DOCKER_BUILD_LOCK" >/dev/null 2>&1 || true
+            echo "✅ Docker build lock released: ${DOCKER_BUILD_LOCK}"
+          else
+            echo "⚡ no Docker build lock to release"
+          fi
+
       # 2026-03-31 ogt: 移除中間通知
 
       # 2026-03-31 ogt: P0-1 Secrets 自動注入 (ADR-035 強制)

docs/LOGBOOK.md

@@ -6,6 +6,19 @@
 
 ---
 
+## 2026-04-30 | CD Runner 並行 Build 修復 — RWLayer nil
+
+AWOOOI CD `Build and Push Web` 在 Gitea act-runner 內失敗：`RWLayer of container ... unexpectedly nil`。Web image 在 110 host 直接 build 成功，排除 Web 程式碼 build error。
+
+### 根因
+- 110 `gitea-runner` 實際使用 `/home/wooo/act-runner/config.yaml`，`runner.capacity: 2`。
+- AWOOOI Web build 還在跑時，runner 於 `2026-04-30T01:26:02Z` 接了另一個 repo task，兩個 task 共用同一個 Docker daemon。
+- AWOOOI job container 隨後消失，BuildKit 回報 `RWLayer ... unexpectedly nil`，後續 notify/post steps 也因 `No such container` 失敗。
+
+### 修法
+- `.gitea/workflows/cd.yaml` 新增 host-global Docker build lock，以 Docker network `awoooi-cd-docker-build-lock` 序列化 API/Web image build。
+- `ops/runner/README.md` 記錄 110 act-runner 必須 `capacity: 1`，並說明 stale lock 清理策略。
+
 ## 2026-04-30 | Prod 部署補救 — AI Telegram / Code Review 落地
 
 Gitea CD runner 在 Docker/act job 容器層反覆出現 `RWLayer ... unexpectedly nil`，導致 `639bb64` 功能 commit 未能進 prod，Telegram 仍顯示舊 ACTION REQUIRED 卡片。

ops/runner/README.md

@@ -87,6 +87,43 @@ sudo systemctl start runner-diag-cleanup.service
 - Memory: `feedback_runner_zombie_process.md`
 - ADR: 待建立 (如果問題持續)
 
+## 問題: Gitea act-runner 並行 Docker Build 讓 Job Container 消失
+
+### 症狀
+
+```
+Error response from daemon: RWLayer of container <id> is unexpectedly nil
+Error response from daemon: No such container: <id>
+```
+
+### 根因分析 (2026-04-30)
+
+1. AWOOOI CD 在 `Build and Push Web` 仍執行 Next.js production build 時，110 的 `gitea-runner` 又接了另一個 repo 的 Actions task。
+2. 兩個 task 共用同一個 Docker daemon 與同一個 act-runner 容器；act-runner `capacity: 2` 允許跨 repo 並行。
+3. 第二個 task 啟動後，第一個 AWOOOI job container 被 Docker/act 清掉，BuildKit 後續只看到 `RWLayer ... unexpectedly nil`。
+4. Web image 在 110 host 直接 `docker build` 可成功，證明不是 Web 程式 build error。
+
+### 修復
+
+1. 110 act-runner 必須單工：
+
+```yaml
+# /home/wooo/act-runner/config.yaml
+runner:
+  capacity: 1
+```
+
+2. AWOOOI CD workflow 需要 Docker daemon 全域 lock：
+
+```yaml
+- name: Acquire Docker Build Lock
+  run: docker network create awoooi-cd-docker-build-lock
+```
+
+實作使用 Docker network 當 host-global lock，因為 `/tmp/flock` 只存在 transient job container 內，無法跨 repo/跨 container 生效。
+
+3. 若 job 非正常中止留下 lock，下一次 CD 會在 lock 超過 2 小時後移除 stale network。
+
 ---
 版本: v2.0 | 更新: 2026-03-29 | 作者: Claude Code
 變更: v1.0→v2.0 序列建構取代 Job Concurrency Groups