一、docker拉取centOs镜像

使用docker命令进行拉取：

docker pull centos : 此种方式是拉取最新版的centOs镜像，

docker pull centos:[版本] ：这种方式可以拉取不同版本的centOs镜像

二、运行centOs容器

使用命令：docker run -it -d --name centos-latest -p 5000:22 --privileged=true centos /sbin/init

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centOs镜像只是最基本的骨架，好多命令不支持，所以先安装一些常用的命令：

1. 安装网络环境

yum -y install net-tools

2. 安装openssh-server

yyum -y install openssh-server

3. 安装vim

yum install vim

4. 安装passwd

yum install passwd

4.1. 修改root密码

[root@7a1b1888cc86 /]# passwd

Changing password for user root.
New password: 
BAD PASSWORD: The password is shorter than 8 characters
Retype new password: 
passwd: all authentication tokens updated successfully.
[root@7a1b1888cc86 /]# 

三、启动容器sshd服务

[root@7a1b1888cc86 /]# /usr/sbin/sshd

如果出现下面的情况：

[root@7a1b1888cc86 /]# /usr/sbin/sshd
Unable to load host key: /etc/ssh/ssh_host_rsa_key
Unable to load host key: /etc/ssh/ssh_host_ecdsa_key
Unable to load host key: /etc/ssh/ssh_host_ed25519_key
sshd: no hostkeys available -- exiting.

执行1：

ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N ""

[root@7a1b1888cc86 /]# ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N ""
Generating public/private rsa key pair.
Your identification has been saved in /etc/ssh/ssh_host_rsa_key.
Your public key has been saved in /etc/ssh/ssh_host_rsa_key.pub.
The key fingerprint is:
SHA256:ythgDxqFyYmXYuY1X/Lin8txH5jmwoDtazqePCCdVXs root@7a1b1888cc86
The key's randomart image is:
+---[RSA 3072]----+
|                 |
| o =  .          |
|ooBo.o o         |
|+o..+ = E        |
| o.o*o oS        |
|..o=.X..  o      |
|. o o.B. = .     |
|  .o.ooo* . .    |
|  .==..=o. .     |
+----[SHA256]-----+

执行2：

ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N ""

[root@7a1b1888cc86 /]# ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N ""
Generating public/private ecdsa key pair.
Your identification has been saved in /etc/ssh/ssh_host_ecdsa_key.
Your public key has been saved in /etc/ssh/ssh_host_ecdsa_key.pub.
The key fingerprint is:
SHA256:6y/gjIVmy6NzaD9i1qTESiJVKxW4aRHvOc0adOG8A+Y root@7a1b1888cc86
The key's randomart image is:
+---[ECDSA 256]---+
|  .o...          |
|  o.oo .         |
|   *=.+          |
|  *=.* .         |
| + .E.= S        |
|o.o =+o. .       |
|+o O.* ..        |
|. O O o..        |
| +.*.o  .o.      |
+----[SHA256]-----+

执行3：

ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N ""

[root@7a1b1888cc86 /]# ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N ""
Generating public/private ed25519 key pair.
Your identification has been saved in /etc/ssh/ssh_host_ed25519_key.
Your public key has been saved in /etc/ssh/ssh_host_ed25519_key.pub.
The key fingerprint is:
SHA256:MpXueojz012ZGl29vrQCr18E3H0oGs/fzmYV8ZVUf1Q root@7a1b1888cc86
The key's randomart image is:
+--[ED25519 256]--+
|              ..E|
|         .  . .=+|
|        o . .o.oO|
|       o   = .o.=|
|      o S ..o+ .o|
|       +  ..=..o.|
|     . o.. +o ooo|
|    o o.o o  oo++|
|     ooo   .o..=+|
+----[SHA256]-----+

最后看下是否成功：

[root@7a1b1888cc86 /]# netstat -antp | grep sshd
[root@7a1b1888cc86 /]# /usr/sbin/sshd
[root@7a1b1888cc86 /]# netstat -antp | grep sshd
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      48/sshd
tcp6       0      0 :::22                   :::*                    LISTEN      48/sshd
[root@7a1b1888cc86 /]#

OK，已经可以远程访问啦！