浅谈docker --privileged=true参数作用

$ docker help run 
...
--privileged=false     Give extended privileges to this container
...

docker run --name mysql-test -e MYSQL_ROOT_PASSWORD=123456 -p 9092:3306 -d daocloud.io/library/mysql:5.7.6

docker run --name mysql-test --privileged=true -e MYSQL_ROOT_PASSWORD=123456 -p 9092:3306 -d daocloud.io/library/mysql:5.7.6

[root@localhost ~]# docker run -t -i centos:latest bash
[root@ed8fee643129 /]# lsblk 
lsblk: dm-0: failed to get device path
lsblk: dm-1: failed to get device path
lsblk: dm-0: failed to get device path
lsblk: dm-1: failed to get device path
NAME  MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vda  252:0  0  80G 0 disk 
|-vda1 252:1  0  1G 0 part 
`-vda2 252:2  0  79G 0 part 
vdb  252:16  0 200G 0 disk 
|-vdb1 252:17  0  50G 0 part 
|-vdb2 252:18  0  50G 0 part 
`-vdb3 252:19  0 100G 0 part 
[root@ed8fee643129 /]# mount /dev/vdb3 /mnt/
mount: permission denied

[root@docker ~]# docker run -t -i --privileged centos:latest bash
[root@f83ce3877aa1 /]# 
[root@f83ce3877aa1 /]# 
[root@f83ce3877aa1 /]# mount /dev/vdb3 /mnt/
[root@f83ce3877aa1 /]# df -h
Filesystem        Size Used Avail Use% Mounted on
overlay          77G  25G  52G 33% /
tmpfs           64M   0  64M  0% /dev
tmpfs          3.9G   0 3.9G  0% /sys/fs/cgroup
/dev/mapper/centos-root  77G  25G  52G 33% /etc/hosts
shm            64M   0  64M  0% /dev/shm
/dev/vdb3        100G  33M 100G  1% /mnt
[root@f83ce3877aa1 /]#