DOCKER学习_014:Docker存储补充

在前面已经学习了Docker的存储,https://www.cnblogs.com/zyxnhr/p/11830238.html,现在对前面的内容的一个补充,具体请参考https://www.cnblogs.com/zyxnhr/p/11830238.html

对docker的数据进行持久化

接上一章实验

[root@docker-server3 nginx]# docker run -d -v /data:/usr/share/nginx/html nginx:v1.4

693f7819a0301e6432d69cc1f278596d96aa8a980050b7d26815b44d9390bc66

[root@docker-server3 nginx]# docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
693f7819a030        nginx:v1.4          "/build.sh nginx -g …"   4 seconds ago       Up 3 seconds                80/tcp              affectionate_chebyshev
3b26204c8758        nginx:v1.4          "/build.sh nginx -g …"   48 minutes ago      Up 48 minutes               80/tcp              thirsty_golick
0fef39ec7ffd        nginx:v1.4          "/build.sh nginx -g …"   50 minutes ago      Up 50 minutes               80/tcp              flamboyant_dirac
9de02f005f66        nginx:v1.3          "/build.sh nginx -g …"   54 minutes ago      Exited (0) 54 minutes ago                       flamboyant_poincare
593a35ccbbf9        nginx:v1.2          "nginx -g 'daemon of…"   About an hour ago   Up About an hour            80/tcp              cool_clarke
55645329c490        nginx:v1.2          "nginx -g 'daemon of…"   About an hour ago   Up About an hour            80/tcp              intelligent_carson
666927b25d2f        nginx:v1.1          "nginx -g 'daemon of…"   2 hours ago         Up 2 hours                  80/tcp              xenodochial_austin

[root@docker-server3 nginx]# docker inspect 693f7819a030 |grep IP

"LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "192.168.0.6",
            "IPPrefixLen": 24,
            "IPv6Gateway": "",
                    "IPAMConfig": null,
                    "IPAddress": "192.168.0.6",
                    "IPPrefixLen": 24,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,

[root@docker-server3 nginx]# curl http://192.168.0.6

自动创建/data目录 

查看/data下数据

[root@docker-server3 nginx]# ll /data/
total 4
-rw-r--r-- 1 root root 12 Jan  2 17:54 index.html
[root@docker-server3 nginx]# cat /data/index.html 
just a test

修改这个数据,会立即生效

[root@docker-server3 nginx]# echo aaaaa > /data/index.html 
[root@docker-server3 nginx]# curl http://192.168.0.6
aaaaa

进入docker容器内部查看

[root@docker-server3 nginx]# docker exec -it 693f7819a030 /bin/bash

[root@693f7819a030 html]# ll
total 4
-rw-r--r-- 1 root root 6 Jan  2 22:57 index.html
[root@693f7819a030 html]# pwd
/usr/share/nginx/html
[root@693f7819a030 html]# cat index.html 
aaaaa
[root@693f7819a030 html]# exit 
exit

实现持久存储

使用Dockerfile的VOLUME指令

[root@docker-server3 nginx]# vi Dockerfile

FROM  centos:7
WORKDIR  /usr/share/nginx/html
ADD  build.sh  /build.sh
RUN yum install -y wget &&  wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo \
    && yum -y install nginx &&  rm -rf index.html && echo "nginx in custom docker"  > index.html && chmod +x /build.sh

EXPOSE 80

ENTRYPOINT ["/build.sh"]
VOLUME  /usr/share/nginx/html
CMD ["nginx","-g","daemon off;"]

[root@docker-server3 nginx]# docker build -t nginx:v1.5  .

[root@docker-server3 nginx]# docker run -d nginx:v1.5

a6c195265c4ba5cd786040988e3e5a11eb0c63b1d726657620a76438fcafdbfe

这里没有指定本机的挂载目录,查看挂载位置

[root@docker-server3 nginx]# docker inspect a6c195265c |grep -A 10 Mount

 "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "journald",
                "Config": {}
            },
--
        "Mounts": [
            {
                "Type": "volume",
                "Name": "fb7d3ec98bf52d43d832088b752417826a893d30719ea11186b3a72981db6b9c",
                "Source": "/var/lib/docker/volumes/fb7d3ec98bf52d43d832088b752417826a893d30719ea11186b3a72981db6b9c/_data",      #挂载的本机位置
                "Destination": "/usr/share/nginx/html",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }

默认挂载的本机位置是"Source": "/var/lib/docker/volumes/fb7d3ec98bf52d43d832088b752417826a893d30719ea11186b3a72981db6b9c/_data"

容器ID下的一个_data目录

[root@docker-server3 nginx]# cd /var/lib/docker/volumes/fb7d3ec98bf52d43d832088b752417826a893d30719ea11186b3a72981db6b9c/_data

[root@docker-server3 _data]# ll

这种挂载会将容器的数据映射出来

[root@docker-server3 _data]# docker run -d -v /tmp/test:/usr/share/nginx/html  nginx:v1.5

2c081745d680548dabda33d1f50043e362dcafbc1ea7e7d878ecb2a70a8d525d
[root@docker-server3 _data]# ll /tmp/test/
total 4
-rw-r--r-- 1 root root 12 Jan  2 18:12 index.html

这种方式就会覆盖掉内容

查看容器内时间

[root@docker-server3 _data]# docker exec -it 2c081745d6  /bin/bash

[root@2c081745d680 html]# date
Thu Jan  2 23:14:54 UTC 2020
[root@2c081745d680 html]# exit
exit

挂载文件

[root@docker-server3 _data]# docker run -d -v /etc/localtime:/etc/localtime  nginx:v1.5

a4883fe9ce664110f7cd270a01d481aa18093f9375703c745fe93a89e6688f63
[root@docker-server3 _data]# docker exec -it a4883fe9c /bin/bash
[root@a4883fe9ce66 html]# date
Thu Jan  2 18:18:08 EST 2020

挂载多个目录

[root@docker-server3 _data]# docker run -d -v /etc/localtime:/etc/localtime -v  /aaaa:/aaaa -v  /tmp/test2:/usr/share/nginx/html   nginx:v1.5

cfafe4c3c1b5d940679aa7eff49096bb4cbc2f112a2007ecf17320ad5e4209ea
[root@docker-server3 _data]# docker exec -it cfafe  /bin/bash    #进入查看
[root@cfafe4c3c1b5 html]# date
Thu Jan  2 18:21:13 EST 2020
[root@cfafe4c3c1b5 html]# ll /usr/share/nginx/html/
total 4
-rw-r--r-- 1 root root 12 Jan  2 18:21 index.html
[root@cfafe4c3c1b5 html]# df -hT
Filesystem              Type     Size  Used Avail Use% Mounted on
overlay                 overlay   47G  4.1G   43G   9% /
tmpfs                   tmpfs     64M     0   64M   0% /dev
tmpfs                   tmpfs    910M     0  910M   0% /sys/fs/cgroup
shm                     tmpfs     64M     0   64M   0% /dev/shm
/dev/mapper/centos-root xfs       47G  4.1G   43G   9% /aaaa               #挂载的
tmpfs                   tmpfs    910M     0  910M   0% /proc/asound
tmpfs                   tmpfs    910M     0  910M   0% /proc/acpi
tmpfs                   tmpfs    910M     0  910M   0% /proc/scsi
tmpfs                   tmpfs    910M     0  910M   0% /sys/firmware

设置挂载目录权限

[root@docker-server3 _data]# docker run -d -v /etc/localtime:/etc/localtime:ro -v  /aaaa:/aaaa:rw -v  /tmp/test2:/usr/share/nginx/html:ro   nginx:v1.5

5ee7277878743c4f9053eb2f7af1dbf19f7bea30dca9992cd7f1b2ffea7bd71c
[root@docker-server3 _data]# docker exec -it 5ee727787 /bin/bash
[root@5ee727787874 html]# touch test.html
touch: cannot touch 'test.html': Read-only file system
[root@5ee727787874 html]# echo 111 > /etc/localtime 
bash: /etc/localtime: Read-only file system
[root@5ee727787874 html]# touch  /aaaa/test.html
[root@5ee727787874 html]# echo 1111 > /aaaa/test.html
[root@5ee727787874 html]# cat /aaaa/test.html
1111

但是可以通过宿主机修改

[root@docker-server3 _data]# echo 2222  /tmp/test2/index.html

2222 /tmp/test2/index.html
[root@docker-server3 _data]# echo 2222 >  /tmp/test2/index.html 
[root@docker-server3 _data]# cat /tmp/test2/index.html
2222
[root@docker-server3 _data]# docker exec -it 5ee727787 /bin/bash
[root@5ee727787874 html]# cat index.html 
2222

删除容器顺便删除挂载的卷,可以指定-v参数

例如:

docker rm -fv 5ee727787874

这种方式可以删除Dockerfile内默认挂载的容器的卷目录,但是对于在外面指定挂载的目录,是没有办法删除的,因为这个目录有可能其他容器在使用,同时还有可能没有权限删除外部的目录

测试

[root@docker-server3 ~]# docker run -d -v /data:/usr/share/nginx/html nginx:v1.5

8c5cd3b90c85c22a7e1d6847bd17fae9cef973d6d2e7a7327b6f35a18ebce8de

[root@docker-server3 ~]# docker rm -fv 8c5cd3b90c85

[root@docker-server3 ~]# ll /data/

自定义目录没有被删除

使用Dockerfile默认的挂载

[root@docker-server3 ~]# docker run -d   nginx:v1.5

63710e4226db67455efe7831e27c4151d8e509624d32f97482f634aac1474c5e

[root@docker-server3 ~]# docker inspect 63710e4226db|grep Mounts -A 10

"Mounts": [
            {
                "Type": "volume",
                "Name": "24dc1433bb9da5cf0739367e03cbdde2ed8a9db8ab320dee72cd3d8629a3d0cc",
                "Source": "/var/lib/docker/volumes/24dc1433bb9da5cf0739367e03cbdde2ed8a9db8ab320dee72cd3d8629a3d0cc/_data",    #默认挂载位置
                "Destination": "/usr/share/nginx/html",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }

[root@docker-server3 ~]# ll /var/lib/docker/volumes/24dc1433bb9da5cf0739367e03cbdde2ed8a9db8ab320dee72cd3d8629a3d0cc/_data

删除容器,但是不指定-v参数

[root@docker-server3 ~]# docker rm -f 63710e4226db

查看容器已经删除,目录还在

[root@docker-server3 ~]# docker ps -a

[root@docker-server3 ~]# ll /var/lib/docker/volumes/24dc1433bb9da5cf0739367e03cbdde2ed8a9db8ab320dee72cd3d8629a3d0cc/_data

重新创建容器,并使用-v参数删除

[root@docker-server3 ~]# docker run -d nginx:v1.5

5347b07f6d15245c17bbe92603a26a610be79788a6fddc1bf9d61eb7a138593b

[root@docker-server3 ~]# docker inspect 5347b07f6d15|grep Mounts -A 10

"Mounts": [
            {
                "Type": "volume",
                "Name": "cc5c93a9923f719873695eecf7309c32d199831da4259ba7451100ccd6efe911",
                "Source": "/var/lib/docker/volumes/cc5c93a9923f719873695eecf7309c32d199831da4259ba7451100ccd6efe911/_data",
                "Destination": "/usr/share/nginx/html",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }

[root@docker-server3 ~]# ll /var/lib/docker/volumes/cc5c93a9923f719873695eecf7309c32d199831da4259ba7451100ccd6efe911/_data

[root@docker-server3 ~]# docker rm -fv 5347b07f6d15

[root@docker-server3 ~]# ll /var/lib/docker/volumes/cc5c93a9923f719873695eecf7309c32d199831da4259ba7451100ccd6efe911/_data

ls: cannot access /var/lib/docker/volumes/cc5c93a9923f719873695eecf7309c32d199831da4259ba7451100ccd6efe911/_data: No such file or directory

使用-v参数,默认挂载的卷已经被删除

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博主声明：本文的内容来源主要来自誉天教育晏威老师，由本人实验完成操作验证，需要的博友请联系誉天教育（http://www.yutianedu.com/），获得官方同意或者晏老师（https://www.cnblogs.com/breezey/）本人同意即可转载，谢谢！