ci: Docker镜像缓存按分支隔离 - develop写回缓存, feature分支只读

- 核心改动：按 GITHUB_REF_NAME 判断分支，develop/main 读写缓存，feature 分支只读不写
- 防止feature分支修改requirements等依赖文件时污染主缓存，导致develop构建偶发50min+
- 新增 npm 缓存 volume，web构建 node_modules 持久化，减少 npm ci 下载时间
- 缓存 tag 从 release 改为 develop，语义更清晰
- 重构 build_with_cache 函数，消除三份重复的 buildx 命令

scripts/build_release_images.sh

@@ -30,7 +30,8 @@ fi
 # ---- Registry 配置 ----
 REGISTRY="${REGISTRY:-git.xiaoxiajianji.com/xiaoxia/xiaoxia-saas}"
 CACHE_REGISTRY="${CACHE_REGISTRY:-git.xiaoxiajianji.com/xiaoxia/xiaoxia-saas}"
-CACHE_TAG="${CACHE_TAG:-release}"
+# 主缓存 tag：develop 分支构建时写入，所有分支读取
+CACHE_TAG_PRIMARY="${CACHE_TAG:-develop}"
 
 API_IMAGE="xiaoxia-saas-api:$VERSION"
 WORKER_IMAGE="xiaoxia-saas-worker:$VERSION"
@@ -45,6 +46,7 @@ REGISTRY_WEB="${REGISTRY}/xiaoxia-saas-web:$VERSION"
 
 USE_CACHE=0
 USE_PUSH=0
+CACHE_WRITE=0
 
 # 检查 buildx 和 Registry 认证
 if docker buildx version >/dev/null 2>&1; then
@@ -54,7 +56,10 @@ if docker buildx version >/dev/null 2>&1; then
   docker buildx use default 2>/dev/null || true
 fi
 
-echo "=== Building API image ==="
+# ---- 缓存读写策略（按分支隔离）----
+# 默认只读不写，防止 feature 分支污染主缓存
+# 只有 develop/main 分支才写回缓存
+BRANCH_NAME="${GITHUB_REF_NAME:-${CI_COMMIT_BRANCH:-unknown}}"
 if [ "$USE_CACHE" -eq 1 ]; then
   docker buildx build \
     --build-arg APP_VERSION="$VERSION" \
@@ -68,6 +73,52 @@ else
   docker build --pull=false --build-arg APP_VERSION="$VERSION" -f infra/docker/api.Dockerfile -t "$API_IMAGE" -t "$API_LATEST" .
 fi
 
+build_with_cache() {
+  # usage: build_with_cache <image_name> <dockerfile> <extra_args...>
+  IMG_NAME="$1"
+  DOCKERFILE="$2"
+  shift 2
+  EXTRA_ARGS="$*"
+
+  CACHE_FROM="type=registry,ref=${CACHE_REGISTRY}/${IMG_NAME}-cache:${CACHE_TAG_PRIMARY},ignore-error=true"
+
+  if [ "$CACHE_WRITE" -eq 1 ]; then
+    CACHE_TO="type=registry,ref=${CACHE_REGISTRY}/${IMG_NAME}-cache:${CACHE_TAG_PRIMARY},mode=max"
+    echo "  cache: read+write from ${CACHE_REGISTRY}/${IMG_NAME}-cache:${CACHE_TAG_PRIMARY}"
+  else
+    CACHE_TO=""
+    echo "  cache: read-only from ${CACHE_REGISTRY}/${IMG_NAME}-cache:${CACHE_TAG_PRIMARY}"
+  fi
+
+  if [ "$USE_CACHE" -eq 1 ]; then
+    if [ -n "$CACHE_TO" ]; then
+      docker buildx build \
+        $EXTRA_ARGS \
+        --cache-from "$CACHE_FROM" \
+        --cache-to "$CACHE_TO" \
+        -f "$DOCKERFILE" \
+        -t "$IMG_NAME:$VERSION" \
+        --load \
+        .
+    else
+      docker buildx build \
+        $EXTRA_ARGS \
+        --cache-from "$CACHE_FROM" \
+        -f "$DOCKERFILE" \
+        -t "$IMG_NAME:$VERSION" \
+        --load \
+        .
+    fi
+  else
+    docker build --pull=false $EXTRA_ARGS -f "$DOCKERFILE" -t "$IMG_NAME:$VERSION" .
+  fi
+}
+
+echo "=== Building API image ==="
+build_with_cache "api" "infra/docker/api.Dockerfile" \
+  "--build-arg APP_VERSION=$VERSION"
+docker tag "$API_IMAGE" "$API_LATEST"
+
 echo "=== Building Worker image ==="
 if [ "$USE_CACHE" -eq 1 ]; then
   docker buildx build \
@@ -83,9 +134,16 @@ else
 fi
 
 echo "=== Building Web image (with buildx cache) ==="
-# 先构建前端产物
+# 先构建前端产物（使用持久化 npm 缓存卷）
+NPM_CACHE_VOLUME="xiaoxia-npm-cache"
+if ! docker volume inspect "$NPM_CACHE_VOLUME" >/dev/null 2>&1; then
+  docker volume create "$NPM_CACHE_VOLUME" >/dev/null
+  echo "  Created npm cache volume: $NPM_CACHE_VOLUME"
+fi
+
 docker run --rm \
   -v "$PWD:/workspace" \
+  -v "$NPM_CACHE_VOLUME:/workspace/apps/web/node_modules" \
   -w /workspace/apps/web \
   docker.m.daocloud.io/library/node:20 \
   sh -lc "npm ci && npm run build"