Dify版本：0.7.2

部署方式：docker

先上图，官方提供的数据库迁移操作，看起来应该是比较老版本的操作了，新版本暂未更新。总体思路就是修改环境变量，再用dify-api中提供的vdb-migrate进行数据库迁移即可。

一、备份

备份一下挂载目录（主要是数据库内容）

tar -cvf volumes-$(date +%s).tgz volumes

二、修改环境变量

找到dify/docker/.env文件修改环境变量，修改VETOR_STORE的值为milvus（默认为weaviate）

（PS：这里我同步修改了compose-config.yml中milvus的版本，并添加了Milvus可视化管理attu，完整配置在文末）

三、重启

docker-compose down
docker-compose up -d

 启动可以看到milvus相关容器已经启动

四、执行迁移命令

docker exec -it docker-api-1 flask vdb-migrate

报错连接失败，信息如下：

2024-09-02 02:11:43,655.655 ERROR [MainThread] [milvus_client.py:655] - Failed to create new connection using: 5993ac3c136a4864a15513e4d0f4f35a
Create dataset index error: MilvusException <MilvusException: (code=2, message=Fail connecting to server on 127.0.0.1:19530, illegal connection params or server unavailable)>

这里看到一条issue说因为端口没有开放，我这里按照提供的方式修改Forgot to expose Milvus standalone port in yaml · Issue #7653 · langgenius/dify (github.com)

替换compose-config.yml中的milvus-standalone为：

  milvus-standalone:
    container_name: milvus-standalone
    image: milvusdb/milvus:v2.3.1
    profiles:
      - milvus
    command: [ "milvus", "run", "standalone" ]
    environment:
      ETCD_ENDPOINTS: ${ETCD_ENDPOINTS:-etcd:2379}
      MINIO_ADDRESS: ${MINIO_ADDRESS:-minio:9000}
      common.security.authorizationEnabled: ${MILVUS_AUTHORIZATION_ENABLED:-true}
    volumes:
      - ./volumes/milvus/milvus:/var/lib/milvus
    healthcheck:
      test: [ "CMD", "curl", "-f", "http://localhost:9091/healthz" ]
      interval: 30s
      start_period: 90s
      timeout: 20s
      retries: 3
    ports:
      - "19530:19530"  # Milvus gRPC port
      - "9091:9091"    # Milvus HTTP port
    depends_on:
      - "etcd"
      - "minio"
    networks:
      - milvus

重新启动后运行迁移仍然报错：

尝试通过Attu连接，发现正常连接到Milvus，如下图：

经历了十多次尝试，得到了最终解决方式：

在compose_config.yml的API中，添加milvus的environment内容。

      MILVUS_HOST: milvus-standalone  # Milvus服务的容器名称
      MILVUS_PORT: 19530              # Milvus服务的端口

五、相关修改代码*

1、attu和milvus新版本compose-config.yml文件内容：（注意：这里由于attu的3000端口被其他占用，我修改为宿主机18000映射3000，有需要可以自行调整）

  # Milvus vector database services
  etcd:
    container_name: milvus-etcd
    image: quay.io/coreos/etcd:v3.5.5
    profiles:
      - milvus
    environment:
      - ETCD_AUTO_COMPACTION_MODE=${ETCD_AUTO_COMPACTION_MODE:-revision}
      - ETCD_AUTO_COMPACTION_RETENTION=${ETCD_AUTO_COMPACTION_RETENTION:-1000}
      - ETCD_QUOTA_BACKEND_BYTES=${ETCD_QUOTA_BACKEND_BYTES:-4294967296}
      - ETCD_SNAPSHOT_COUNT=${ETCD_SNAPSHOT_COUNT:-50000}
    volumes:
      - ./volumes/milvus/etcd:/etcd
    command: etcd -advertise-client-urls=http://127.0.0.1:2379 -listen-client-urls http://0.0.0.0:2379 --data-dir /etcd
    healthcheck:
      test: [ "CMD", "etcdctl", "endpoint", "health" ]
      interval: 30s
      timeout: 20s
      retries: 3
    networks:
      - milvus

  minio:
    container_name: milvus-minio
    image: minio/minio:RELEASE.2023-03-20T20-16-18Z
    profiles:
      - milvus
    environment:
      MINIO_ACCESS_KEY: ${MINIO_ACCESS_KEY:-minioadmin}
      MINIO_SECRET_KEY: ${MINIO_SECRET_KEY:-minioadmin}
    ports:
      - "9001:9001"
      - "9000:9000"
    volumes:
      - ./volumes/milvus/minio:/minio_data
    command: minio server /minio_data --console-address ":9001"
    healthcheck:
      test: [ "CMD", "curl", "-f", "http://localhost:9000/minio/health/live" ]
      interval: 30s
      timeout: 20s
      retries: 3
    networks:
      - milvus

  milvus-standalone:
    container_name: milvus-standalone
    image: milvusdb/milvus:v2.4.9
    profiles:
      - milvus
    command: [ "milvus", "run", "standalone" ]
    environment:
      ETCD_ENDPOINTS: ${ETCD_ENDPOINTS:-etcd:2379}
      MINIO_ADDRESS: ${MINIO_ADDRESS:-minio:9000}
      common.security.authorizationEnabled: ${MILVUS_AUTHORIZATION_ENABLED:-true}
    volumes:
      - ./volumes/milvus/milvus:/var/lib/milvus
    healthcheck:
      test: [ "CMD", "curl", "-f", "http://localhost:9091/healthz" ]
      interval: 30s
      start_period: 90s
      timeout: 20s
      retries: 3
    ports:
      - "19530:19530"
      - "9091:9091"
    depends_on:
      - "etcd"
      - "minio"
    networks:
      - milvus

  attu:
    container_name: attu
    profiles:
      - milvus
    image: zilliz/attu:v2.4.7
    environment:
      MILVUS_URL: milvus-standalone:19530
    ports:
      - "18000:3000"
    depends_on:
      - "milvus-standalone"
    networks:
      - milvus

2、api和web环境变量设置（后续测试发现都需配置环境变量才能正常使用）

  # API service
  api:
    image: langgenius/dify-api:0.7.2
    restart: always
    environment:
      # Use the shared environment variables.
      <<: *shared-api-worker-env
      # Startup mode, 'api' starts the API server.
      MODE: api
      MILVUS_HOST: milvus-standalone  # Milvus服务的容器名称
      MILVUS_PORT: 19530              # Milvus服务的端口
    depends_on:
      - db
      - redis
    volumes:
      # Mount the storage directory to the container, for storing user files.
      - ./volumes/app/storage:/app/api/storage
    networks:
      - ssrf_proxy_network
      - default

  # worker service
  # The Celery worker for processing the queue.
  worker:
    image: langgenius/dify-api:0.7.2
    restart: always
    environment:
      # Use the shared environment variables.
      <<: *shared-api-worker-env
      # Startup mode, 'worker' starts the Celery worker for processing the queue.
      MODE: worker
      MILVUS_HOST: milvus-standalone  # Milvus服务的容器名称
      MILVUS_PORT: 19530              # Milvus服务的端口
    depends_on:
      - db
      - redis
    volumes:
      # Mount the storage directory to the container, for storing user files.
      - ./volumes/app/storage:/app/api/storage
    networks:
      - ssrf_proxy_network
      - default

  # Frontend web application.
  web:
    image: langgenius/dify-web:0.7.2
    restart: always
    environment:
      CONSOLE_API_URL: ${CONSOLE_API_URL:-}
      APP_API_URL: ${APP_API_URL:-}
      SENTRY_DSN: ${WEB_SENTRY_DSN:-}
      NEXT_TELEMETRY_DISABLED: ${NEXT_TELEMETRY_DISABLED:-0}
      MILVUS_HOST: milvus-standalone  # Milvus服务的容器名称
      MILVUS_PORT: 19530              # Milvus服务的端口

参考内容：

本地部署相关 | 中文 (dify.ai)