%% IT 智能服务台 — 部署时序图（卷挂载重构）
%% 文件: sequence-diagram.mermaid

sequenceDiagram
    participant Ops as 运维人员
    participant Host as 宿主机 10.90.5.110
    participant Docker as Docker Engine
    participant Container as Backend 容器

    Note over Ops,Container: S1: 前置验证与备份
    Ops->>Host: curl /health 验证当前状态
    Host-->>Ops: 200 OK
    Ops->>Host: 备份 docker-compose.yml → .bak.{TIMESTAMP}
    Ops->>Host: 备份 Dockerfile → .bak.{TIMESTAMP}
    Ops->>Host: 写入 .rollback-info 文件

    Note over Ops,Container: S2: 代码验证
    Ops->>Host: 检查 app/__init__.py, app/main.py
    Ops->>Host: 检查 app/api/auth.py（关键！）
    Host-->>Ops: 全部存在

    Note over Ops,Container: S3: 修改 Dockerfile
    Ops->>Host: 重写 Dockerfile
    Note right of Host: 删除 COPY . .<br/>新增 ENV PYTHONDONTWRITEBYTECODE=1
    Ops->>Host: grep 验证 COPY . . 已删除

    Note over Ops,Container: S4: 修改 docker-compose.yml
    Ops->>Host: sed 插入 ./app:/app/app 卷挂载
    Ops->>Host: grep 验证卷挂载已添加

    Note over Ops,Container: S5: 重建镜像并重启
    Ops->>Docker: docker compose build backend
    Docker->>Docker: 构建镜像（仅 site-packages）
    Note right of Docker: 镜像不含业务代码
    Ops->>Docker: docker compose up -d backend
    Docker->>Container: 创建容器
    Docker->>Host: 挂载 ./app → /app/app (bind mount)
    Container->>Host: 运行时读取 /opt/wecom-it-desk/app/ 代码
    Container->>Container: uvicorn app.main:app 启动

    Note over Ops,Container: S6: 部署后验证
    Ops->>Container: curl http://localhost:8000/health
    Container-->>Ops: 200 OK
    Ops->>Container: docker exec ... from app.auth import router
    Container-->>Ops: auth module: OK
    Ops->>Host: md5sum app/main.py
    Ops->>Container: docker exec md5sum /app/app/main.py
    Note right of Ops: 对比 hash 一致 → 卷挂载正常

    Note over Ops,Container: S7: 清理（48小时后）
    Ops->>Host: rm -rf backend/app/
    Ops->>Host: 确认服务仍正常