# Docker  安装 Ubuntu

1. 首先从云上拉取 ubuntu 的镜像

    ```sh
    docker pull ubuntu
    ```

     使用 `docker images` 或 `docker image ls`  查看刚才摘取下来的镜像
     
    ![docker_pull_img](https://img2023.cnblogs.com/blog/376834/202412/376834-20241210113502081-740644074.png)

    如上图示镜像 ID 为 `b1d9df8ab815`

2. 启动镜像

   输入命令 `docker run -itd -p 6789:22 b1d9df8ab815`，表示在后台启动镜像，并将本机的 `6789`  端口映射到容器的 `22` 端口，最后字符串是 IMAGES ID.
   只要没有报错，显示一串字符就说明镜像启动成功，可以通过命令 `docker container ls` 或 `docker ps` 来查看运行的容器：
    
   ![container_img](https://img2023.cnblogs.com/blog/376834/202412/376834-20241210121734810-258680536.png)

    
   如上图示，容器的 ID 为 `7761329a4cc6`

3. 进入容器，下载 openssh-server, 并修改 ssh 的配置，启动 ssh

    输入命令`docker exec -it 7761329a4cc6 /bin/bash` 进入容器，执行命令：

    ```sh
    root@7761329a4cc6:/# apt-get update
    Get:1 http://archive.ubuntu.com/ubuntu noble InRelease [256 kB]
    Get:2 http://security.ubuntu.com/ubuntu noble-security InRelease [126 kB]
    ...
    Get:17 http://archive.ubuntu.com/ubuntu noble-backports/universe amd64 Packages [11.9 kB]
    Fetched 26.6 MB in 20s (1361 kB/s)
    Reading package lists... Done
    root@7761329a4cc6:/# apt-get upgrade
    ...
    root@7761329a4cc6:/# apt-get install openssh-server
    Reading package lists... Done
    Building dependency tree... Done
    Reading state information... Done
    ...
    0 upgraded, 82 newly installed, 0 to remove and 0 not upgraded.
    Need to get 34.8 MB of archives.
    After this operation, 123 MB of additional disk space will be used.
    Do you want to continue? [Y/n] y
    ...
    Updating certificates in /etc/ssl/certs...
    0 added, 0 removed; done.
    Running hooks in /etc/ca-certificates/update.d...
    done
    ```

4. 设置 root 密码

   ```sh
   root@7761329a4cc6:/# passwd
   ```

5. 修改 SSH 配置文件

   ```sh
   root@7761329a4cc6:/# vim /etc/ssh/sshd_config
   ```

   ![img](https://img2023.cnblogs.com/blog/376834/202412/376834-20241210123542500-101364487.png)

   注释一行 `#PermitRootLogin prohibit-password`

   添加一行 `PermitRootLogin yes` ，然后保存退出

6. 重启 SSH 服务

    ```sh
    root@7761329a4cc6:/# /etc/init.d/ssh restart
    * Restarting OpenBSD Secure Shell server sshd            [ OK ]
    # 自动启动
    root@7761329a4cc6:/# systemctl enable ssh
    ```

7. 本机连接 ssh

   ```sh
   (base) ➜  ~ ssh root@0.0.0.0 -p 6789
   The authenticity of host '[0.0.0.0]:6789 ([0.0.0.0]:6789)' can't be established.
    ECDSA key fingerprint is SHA256:vXNa4BXo0s63JV8VqLDD3iV5E+xEsuV/DdEkldeX7fQ.
    Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
    root@0.0.0.0's password:
    Welcome to Ubuntu 24.04.1 LTS (GNU/Linux 5.10.25-linuxkit x86_64)

    * Documentation:  https://help.ubuntu.com
    * Management:     https://landscape.canonical.com
    * Support:        https://ubuntu.com/pro

    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.

    The programs included with the Ubuntu system are free software;
    the exact distribution terms for each program are described in the
    individual files in /usr/share/doc/*/copyright.

    Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
    applicable law.

    root@7761329a4cc6:~#
   ```

    如上示， 输入 `yes` 同意加密认证，然后输入登陆密码，就可以远程返回 docker 系统

8. 容器导出

   ```sh
    # 如上图示，容器的 ID 为 `7761329a4cc6`
   (base) ➜  ~ docker export 7761329a4cc6 > ssh_ubuntu.tar
   ```

    如上示导出容器 `7761329a4cc6` 快照到本地文件 `ssh_ubuntu.tar`。

9. 导入容器快照
    可以使用 `docker import`  从容器快照中再导入为镜像， 以下将快照文件`ssh_ubuntu.tar`导入到镜像 `ssh/ubuntu:v1`

    ```sh
    (base) ➜  ~ cat ssh_ubuntu.tar | docker import - ssh/ubuntu:v1
    sha256:995020b3864b182e012c1a128dd4be3c479289d42ae642321577d779bca223a6 
    ```

    ![img](https://img2023.cnblogs.com/blog/376834/202412/376834-20241211171235539-1010537636.png)