volume介绍和操作

一.volume 介绍

提供独立于容器之外的持久化存储，比如说运行一个数据库容器，数据库里面的数据就是需要被持久化的，volume就可以做到这个功能实现，并且还能共享容器与容器之间的数据。

二.volume 操作

方式一，以默认的目录挂载到指定的容器 目录中

docker run -d  --name nginx  -v /usr/share/nginx/html nginx   

docker inspect nginx  查看所有的容器

     },
        "Mounts": [
            {
                "Type": "volume",
                "Name": "daad412457c85a5ee10504928d9d2d642e45d5deb571ae762aa1e25e45925674",
                "Source": "/var/lib/docker/volumes/daad412457c85a5ee10504928d9d2d642e45d5deb571ae762aa1e25e45925674/_data",
                "Destination": "/usr/share/nginx/html",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],
        "Config": {
            "Hostname": "46e50083988e",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "NGINX_VERSION=1.15.2-1~stretch",
                "NJS_VERSION=1.15.2.0.2.2-1~stretch"
            ],
            "Cmd": [
                "nginx",
                "-g",
                "daemon off;"
            ],
            "ArgsEscaped": true,
            "Image": "nginx",
            "Volumes": {
                "/usr/share/nginx/html": {}
            },
            "WorkingDir": "",
            "Entrypoint": null,
            "OnBuild": null,
            "Labels": {
                "maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
            },
            "StopSignal": "SIGTERM"
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "d23f93abdf77ecdd101c7c8ed63bf4b21c08aaee28120c53493fb30363ef2c06",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": null,
            "SandboxKey": "/var/run/docker/netns/d23f93abdf77",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "",
            "Gateway": "",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "",
            "IPPrefixLen": 0,
            "IPv6Gateway": "",
            "MacAddress": "",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "e9a5c3a2efc45030b88a90fcf3db7d3e22282a98ba2862a00992db2b1a2cc82f",
                    "EndpointID": "",
                    "Gateway": "",
                    "IPAddress": "",
                    "IPPrefixLen": 0,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": ""
                }
            }
        }
    }
]

    "Source": "/var/lib/docker/volumes/daad412457c85a5ee10504928d9d2d642e45d5deb571ae762aa1e25e45925674/_data",
                "Destination": "/usr/share/nginx/html",

重点为此处，将本地的source 对应的目录挂载到 nginx 的访问页面目录 。

 docker exec -it nginx /bin/bash    进入容器内部

方式二.将指定的当前目录的html目录挂载到指定的容器中

 docker run -p 80:80 -d -v $PWD/html:/usr/share/nginx/html nginx   将当前目录下的html目录挂载到容器里面的/usr/share/nginx/html 目录

curl  http://localhost:  输出的内容即为当前目录下的html目录中的index.html文件的内容

 docker create -v $PWD/data:/var/mydata --name data_container ubuntu  、

将data_container 容器的/var/mydata 挂载到 ubuntu 容器里面

docker run -it --volumes-from data_container ubuntu /bin/bash

进入到Ubuntu容器里面 ，

mount 命令  查看所有挂载

发现 已经把 data_container 的/var/mydata挂载上来了

cd  /var/mydata

 touch whatever.txt

ctrl+d 或者 exit 退出当前容器

cd  data 发现本地的目录中也创建 了一个 whatever.txt文件

多个容器之间可以互相挂载，以便做到数据共享。