基于commit命令创建

1. 生成密钥对

在需要利用ssh命令远程访问docker容器的机器上，利用ssh-keygen命令生成密钥对：

$ ssh-keygen -t rsa

2.启动docker容器

下载并启动一个用于提供ssh服务的docker容器：

$ docker run -itd --name sshd -p 10220:22 ubuntu:18.04

3.安装ssh服务

在容器中安装openssh-server：

$ docker exec sshd apt-get update
$ docker exec sshd apt-get install -y openssh-server

4. 启动ssh服务

如果需要正常启动SSH服务，则目录 /var/run/sshd必须存在。下面手动创建它，并启动SSH服务：

$ docker exec sshd mkdir -p /var/run/sshd
$ docker exec -d sshd /usr/sbin/sshd -D

5. 免密登录

将宿主机的公钥复制到容器的authorized_keys中：

$ docker exec sshd \
    sh -c "mkdir -p ~/.ssh"
$ docker exec sshd \
    sh -c "echo $(cat ~/.ssh/id_rsa.pub) >> ~/.ssh/authorized_keys"

6. 登录测试

使用ssh命令访问容器，注意：只有配置了免密登录的用户才能够访问，其他未配置免密的用户会报Permission Denied错误！

$ ssh root@localhost -p 10220
Welcome to Ubuntu 18.04.6 LTS (GNU/Linux 3.10.0-1160.el7.x86_64 x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage
This system has been minimized by removing packages and content that are
not required on a system that users do not log into.

To restore this content, you can run the 'unminimize' command.
Last login: Thu Oct 19 13:08:02 2023 from 172.17.0.1
root@6a02d44fc0cf:~# 

7. 提交镜像并试用

1. 使用docker commit命令提交镜像：

   $ docker commit -a zhang -m "add sshd service" sshd sshd:1.0
   sha256:1583d2c535cbdd412f11e4320f75f801646f668a83c2bea47c42b067f9e5b7c1
   
   $ docker images
   REPOSITORY       TAG       IMAGE ID       CREATED         SIZE
   sshd             1.0       1583d2c535cb   4 seconds ago   224MB

2. 使用镜像：

   $ docker run -d --name sshd2 -p 10221:22 sshd:1.0 /usr/sbin/sshd -D
   01dde85847fecb73ea1a27a98e54b63ab0ef720962b34941da019368f3cc4155
   
   $ ssh root@localhost -p 10221
   The authenticity of host '[localhost]:10221 ([::1]:10221)' can't be established.
   ECDSA key fingerprint is SHA256:MA3b1evMkCpTsuv6AGpy3DUsuFSxlqmwtMNtg837G/M.
   ECDSA key fingerprint is MD5:84:69:9d:12:6b:15:4d:c6:0a:66:53:91:78:4d:61:68.
   Are you sure you want to continue connecting (yes/no)? yes
   Warning: Permanently added '[localhost]:10221' (ECDSA) to the list of known hosts.
   Welcome to Ubuntu 18.04.6 LTS (GNU/Linux 3.10.0-1160.el7.x86_64 x86_64)
   
    * Documentation:  https://help.ubuntu.com
    * Management:     https://landscape.canonical.com
    * Support:        https://ubuntu.com/advantage
   This system has been minimized by removing packages and content that are
   not required on a system that users do not log into.
   
   To restore this content, you can run the 'unminimize' command.
   Last login: Thu Oct 19 13:12:07 2023 from 172.17.0.1
   root@01dde85847fe:~#