以mongodb8.0.3为例。

1 创建mongo数据库时未挂载数据到宿主机

version: '3.1'
services:
  mongo_test:
    container_name: mongo_test
    restart: always
    image: mongo:8.0.3
    ports:
    - 17017:27017
    volumes:
      - /etc/localtime:/etc/localtime:ro # 将外边时间直接挂载到容器内部，权限只读
      #- /opt/soft/mongo/mongo_test/data:/data/db
      #- /opt/soft/mongo/mongo_test/conf:/data/configdb
      - /opt/soft/mongo/keyfile.key:/data/configdb/keyfile.key
    environment:
      TZ: Asia/Shanghai  # 设置时区为上海时区
      MONGO_INITDB_ROOT_USERNAME: root
      MONGO_INITDB_ROOT_PASSWORD: 123456
    logging:
      driver: json-file
      options:
        max-size: 10m
        max-file: 5
    networks:
      - mongo

networks:
  mongo:
    driver: bridge

2 查找数据卷位置

数据卷通常存储在/var/lib/docker/volumes/目录下。每个数据卷都有一个对应的文件夹。可以使用docker volume ls列出所有容器使用的数据卷，然后使用docker inspect <volume_name>查看特定数据卷的详细信息，找到其在宿主机上的存储路径。

[root@node01 mongo]# docker volume ls
DRIVER    VOLUME NAME
local     93bb1c65b0329a2050c29f2ef35eee4761a86029f1222e4f9df7d332a2bb6381
local     f789fdd5ef3c229c7c1cb19a1478a7aba7416490191a563572eaf010f12317a2

[root@node01 mongo]# ls /var/lib/docker/volumes/
93bb1c65b0329a2050c29f2ef35eee4761a86029f1222e4f9df7d332a2bb6381  

backingFsBlockDev  

f789fdd5ef3c229c7c1cb19a1478a7aba7416490191a563572eaf010f12317a2  

metadata.db

可以发现宿主机上的两个目录正是docker容器使用的卷。

容器存在时，可通过查看容器内数据默认的挂载找到对应关系：

docker inspect mongo_test


        "Mounts": [
            {
                "Type": "bind",
                "Source": "/opt/soft/mongo/keyfile.key",
                "Destination": "/data/configdb/keyfile.key",
                "Mode": "rw",
                "RW": true,
                "Propagation": "rprivate"
            },
            {
                "Type": "volume",
                "Name": "f789fdd5ef3c229c7c1cb19a1478a7aba7416490191a563572eaf010f12317a2",
                "Source": "/var/lib/docker/volumes/f789fdd5ef3c229c7c1cb19a1478a7aba7416490191a563572eaf010f12317a2/_data",
                "Destination": "/data/configdb",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            },
            {
                "Type": "volume",
                "Name": "93bb1c65b0329a2050c29f2ef35eee4761a86029f1222e4f9df7d332a2bb6381",
                "Source": "/var/lib/docker/volumes/93bb1c65b0329a2050c29f2ef35eee4761a86029f1222e4f9df7d332a2bb6381/_data",
                "Destination": "/data/db",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            },
            {
                "Type": "bind",
                "Source": "/etc/localtime",
                "Destination": "/etc/localtime",
                "Mode": "ro",
                "RW": false,
                "Propagation": "rprivate"
            }
        ]

如果容器不存在，可创建一个不挂载文件的新容器，从而分析已删除的原容器数据卷和宿主机上的卷积对应关系。

综上可以了解，上述两个数据卷是容器mongo_test使用的，且有如下对应关系：

/var/lib/docker/volumes/f789fdd5ef3c229c7c1cb19a1478a7aba7416490191a563572eaf010f12317a2:/data/configdb

/var/lib/docker/volumes/93bb1c65b0329a2050c29f2ef35eee4761a86029f1222e4f9df7d332a2bb6381:/data/db

3 将容器在宿主机上的数据复制到指定目录下

mkdir -p /opt/soft/mongo/mongo_test/{conf,data}
chmod 777 /opt/soft/mongo/mongo_test/data
chmod 777 /opt/soft/mongo/mongo_test/conf

cp -R /var/lib/docker/volumes/f789fdd5ef3c229c7c1cb19a1478a7aba7416490191a563572eaf010f12317a2/_data/* /opt/soft/mongo/mongo_test/conf

cp -R /var/lib/docker/volumes/93bb1c65b0329a2050c29f2ef35eee4761a86029f1222e4f9df7d332a2bb6381/_data/* /opt/soft/mongo/mongo_test/data

4 修改docker-compose并挂载数据（注意端口）

version: '3.1'
services:
  mongo_test:
    container_name: mongo_test
    restart: always
    image: mongo:8.0.3
    ports:
    - 17017:27017
    volumes:
      - /etc/localtime:/etc/localtime:ro # 将外边时间直接挂载到容器内部，权限只读
      - /opt/soft/mongo/mongo_test/data:/data/db
      - /opt/soft/mongo/mongo_test/conf:/data/configdb
      - /opt/soft/mongo/keyfile.key:/data/configdb/keyfile.key
    environment:
      TZ: Asia/Shanghai  # 设置时区为上海时区
      MONGO_INITDB_ROOT_USERNAME: root
      MONGO_INITDB_ROOT_PASSWORD: 123456
    logging:
      driver: json-file
      options:
        max-size: 10m
        max-file: 5
    networks:
      - mongo

networks:
  mongo:
    driver: bridge

5 重新运行新容器

docker-compose up -d

至此，Docker容器数据恢复就完成了。