容器数据卷

为什么

容器的数据只存在容器内，如果容器被删，数据也会被一并删掉
用卷技术可以将容器内数据映射到服务器上，达到同步

数据持久化和同步，容器之间数据共享！

数据卷挂载（创建容器时）

-v - volume全称

docker run -it -v 本机目录:容器内目录

//测试
[root@d7e95b07ab8f home]# touch parallel.java
[root@d7e95b07ab8f home]# ls
parallel.java
[root@d7e95b07ab8f home]# read escape sequence
[root@izwz9i11llygg6kvs2igtmz ceshi]# cd /home/ceshi
[root@izwz9i11llygg6kvs2igtmz ceshi]# ls
parallel.java
[root@izwz9i11llygg6kvs2igtmz ceshi]#
//inspect命令检查
//以下是挂载相关配置信息
        "Mounts": [
            {
                "Type": "bind",
                "Source": "/home/ceshi",
                "Destination": "/home",
                "Mode": "",
                "RW": true,
                "Propagation": "rprivate"
            }
        ],
//这样我们的本机文件夹和容器文件夹是一个“双向绑定”关系了
相当于“硬链接”的概念

MySql同步数据

docker run -d -p 3310:3306 -v /home/mysql/conf:/etc/mysql/conf.d -v /home/mysql/data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 --name mysql01 mysql:5.7

-d 后台运行
-p 本机端口:容器端口
-v 本机目录：容器目录
-e 环境配置
--name 重命名容器名

这样我们就实现了数据持久化！

匿名挂载

可以看到它在volume name中是一个编码的形式，我们把这样的叫做匿名挂载。

docker run -d -P -v /etc/nginx --name nginx02 nginx
-P 随机端口

//代码运行记录
[root@izwz9i11llygg6kvs2igtmz mysql]# docker run -d -P -v /etc/nginx --name nginx02 nginx
4cb252a598aab63d77a22b27cae86fed9147cce2211a8c41373a99a46a731cf8
[root@izwz9i11llygg6kvs2igtmz mysql]# docker volume ls
DRIVER              VOLUME NAME
local               3b118d8f565bb9441d2640ed6b3325b1a11e7a9da68b48c9d2648061fe4c63f4
local               5c0f49e2fb6b4cfc678a395e6fe7f139452814f1b66d98fa5f8a68015e98d95c
local               2353adb8b0e506d39cf7a6d627d480e6247f8482b648a57f1e654e15d28eb45b
local               beb3ddb83851d2a6bfdde65ba41e860b818ef9e7b93e42efe4be4cf12bf763a4
local               c7a826f9f75bf8756a02a9a06cf106f36d3ebab82e767bfbec76a4c7a1a41424
local               ea98d50d4b9dc8d3ff81b0bae0007c0ad6265d1aecb7061e2c07b2d48c3c9d2c

具名挂载（推荐）

主要在 -v 具名:容器目录

docker run -d -P -v 具体名字:/etc/nginx --name nginx02 nginx

[root@izwz9i11llygg6kvs2igtmz mysql]# docker run -d -P -v specificName:/etc/nginx --name nginx03 nginx
7e12e95a7410a35fcb82176d37267f475a3cfef69b3d5f575496475e363e5da3
[root@izwz9i11llygg6kvs2igtmz mysql]# docker volume ls
DRIVER              VOLUME NAME
local               3b118d8f565bb9441d2640ed6b3325b1a11e7a9da68b48c9d2648061fe4c63f4
local               5c0f49e2fb6b4cfc678a395e6fe7f139452814f1b66d98fa5f8a68015e98d95c
local               2353adb8b0e506d39cf7a6d627d480e6247f8482b648a57f1e654e15d28eb45b
local               beb3ddb83851d2a6bfdde65ba41e860b818ef9e7b93e42efe4be4cf12bf763a4
local               c7a826f9f75bf8756a02a9a06cf106f36d3ebab82e767bfbec76a4c7a1a41424
local               ea98d50d4b9dc8d3ff81b0bae0007c0ad6265d1aecb7061e2c07b2d48c3c9d2c
local               specificName

查找挂载目录

查找挂载目录不论是具名还是匿名都可以查，根据volume name进行查找

docker inspect specificName

[root@izwz9i11llygg6kvs2igtmz mysql]# docker inspect specificName
[
    {
        "CreatedAt": "2020-08-06T17:07:23+08:00",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/specificName/_data",
        "Name": "specificName",
        "Options": null,
        "Scope": "local"
    }
]

这就是匿名挂载的本地数据路径
"Mountpoint": "/var/lib/docker/volumes/specificName/_data",

总结

具体路径挂载
-v 宿主机路径:容器路径
//匿名挂载
-v 容器路径
//匿名挂载
-v 具名:容器路径

拓展权限

docker run -d -P -v 具体名字:/etc/nginx:ro --name nginx02 nginx
docker run -d -P -v 具体名字:/etc/nginx:rW --name nginx02 nginx
RO 只能通过宿主机来修改
RW 宿主机和容器都可修改

DockerFile（创建镜像时）

这种方式相当于是在创建镜像的时候通过命令来进行挂载操作，上面的-v 是在创建容器的时候进行挂载操作

核心操作

//编辑一个文件
vim dockerfile1
//文件内容
FROM centos 
VOLUME ["volume01","volume02"]
CMD echo "----end----"
CMD /bin/bash
//构建镜像
docker build -f /home/test_volume/dockerfile -t kuangshen/centos:1.0 .

运行结果

运行结果
[root@izwz9i11llygg6kvs2igtmz test_volume]# docker build -f /home/test_volume/dockerfile -t sms/centos:1.0 .
Sending build context to Docker daemon  2.048kB
Step 1/4 : FROM centos
 ---> 831691599b88
Step 2/4 : VOLUME ["volume01","volume02"]
 ---> Running in ef3b8edec5d6
Removing intermediate container ef3b8edec5d6
 ---> 02bb64ce3956
Step 3/4 : CMD echo "----end----"
 ---> Running in fcc14de27af0
Removing intermediate container fcc14de27af0
 ---> 5a895f2b4e27
Step 4/4 : CMD /bin/bash
 ---> Running in 2fbec8aada1d
Removing intermediate container 2fbec8aada1d
 ---> 5303b29ad6f9
Successfully built 5303b29ad6f9
Successfully tagged sms/centos:1.0
[root@izwz9i11llygg6kvs2igtmz test_volume]# docker images
REPOSITORY            TAG                 IMAGE ID            CREATED             SIZE
sms/centos            1.0                 5303b29ad6f9        4 seconds ago       215MB
hello-world           latest              bf756fb1ae65        7 months ago        13.3kB
[root@izwz9i11llygg6kvs2igtmz test_volume]#

inspect一下

inspect一下镜像对应的容器
            "Volumes": {
                "volume01": {},
                "volume02": {}
            },
            //挂载详细
            "Mounts": [
            {
                "Type": "volume",
                "Name": "ed99b948e40fdf2c2d099f32e928d4e20c1231a15b94b50d9d331800b00934fb",
                "Source": "/var/lib/docker/volumes/ed99b948e40fdf2c2d099f32e928d4e20c1231a15b94b50d9d331800b00934fb/_data",
                "Destination": "volume01",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            },
            {
                "Type": "volume",
                "Name": "34c8a98b85ab4d5b1020033851fbd35ebd7a6c8965140d56bda790deb3ea3191",
                "Source": "/var/lib/docker/volumes/34c8a98b85ab4d5b1020033851fbd35ebd7a6c8965140d56bda790deb3ea3191/_data",
                "Destination": "volume02",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],