docker使用ssh远程连接容器(没钱买服务器又不想安装虚拟机患者必备)

突然有需求，需要使用go语言写个ssh终端连接功能，这时候手上又没有服务器，虚拟机也没有，正好使用docker搞起来

docker容器开启sshd服务，模拟服务器

我们知道docker是可以用exec来直接访问容器的，但是还不够high，有时候要模拟服务器的登录总不能用docker exec吧，来吧，老司机带你飞！

以centos为例，需要几步操作

1.安装openssh-server

2.初始化root用户密码

3.开启sshd服务

废话不多说，dockerfile献上

FROM centos
RUN yum install -y wget && \
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo  && \
yum install -y passwd && \
yum install -y openssh-server  ssh-keygen && \
echo 'abcd1234' | passwd root --stdin
RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N "" -q && \
ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N "" -q && \
ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N "" -q
#RUN systemctl enable sshd
CMD /usr/sbin/sshd && tail -f /var/log/wtmp

简单解释一下，

• 安装openssh-server

yum install -y wget && \
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo  && \
yum install -y passwd && \
yum install -y openssh-server  ssh-keygen

• 修改root密码为88888888

echo '' | passwd root --stdin

• 创建ssh-keygen创建相关的ssh文件，-q的意思是静默模式（就是默认是需要让你回车输入的，加上这个直接跳过）

RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N "" -q && \
ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N "" -q && \
ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N "" -q

• 开启sshd服务，并用tail来前台执行阻止docker容器退出

CMD /usr/sbin/sshd && tail -f /var/log/wtmp

一、构建镜像

Dockerfile目录下执行，yeah，就是chenqionghe/centos镜像，你也可以弄成自己的，例如muscle/lightwegiht

docker build -t chenqionghe/centos .

二、运行容器

docker run --name centos_ssh -p 2222:22 -it chenqionghe/centos　　

三、使用ssh连接容器

这里使用了2222端口来映射容器里的22端口，运行起来就可以使用ssh连接了，输出设置好的88888888密码，注意，这里用的是2222映射的端口　　

➜  ~ ssh root@127.0.0.1 -p 2222
root@127.0.0.1's password:
Last login: Tue Nov 20 04:10:17 2018 from 172.17.0.1
[root@a8c8e0fbd74f ~]# ls -l /
total 56
-rw-r--r--   1 root root 12030 Oct  6 19:15 anaconda-post.log
lrwxrwxrwx   1 root root     7 Oct  6 19:14 bin -> usr/bin
drwxr-xr-x   5 root root   360 Nov 20 04:09 dev
drwxr-xr-x  54 root root  4096 Nov 20 04:09 etc
drwxr-xr-x   2 root root  4096 Apr 11  2018 home
lrwxrwxrwx   1 root root     7 Oct  6 19:14 lib -> usr/lib
lrwxrwxrwx   1 root root     9 Oct  6 19:14 lib64 -> usr/lib64
drwxr-xr-x   2 root root  4096 Apr 11  2018 media
drwxr-xr-x   2 root root  4096 Apr 11  2018 mnt
drwxr-xr-x   2 root root  4096 Apr 11  2018 opt
dr-xr-xr-x 223 root root     0 Nov 20 04:09 proc

以上就是使用docker开启ssh模拟服务器的全过程，

附上ubuntu的Dockerfile，原理大同小异

FROM ubuntu:18.04
 
# Ali apt-get source.list
RUN mv /etc/apt/sources.list /etc/apt/sources.list.bak && \
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse" >> /etc/apt/sources.list && \
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse" >> /etc/apt/sources.list
 
#安装openssh-server
RUN apt-get -y update && apt-get -y upgrade && apt-get install -y openssh-server
 
#修改默认密码
RUN echo 'root:88888888' | chpasswd
RUN mkdir -p /run/sshd
# 允许登录
RUN sed -i "s/#PermitRootLogin.*/PermitRootLogin yes/g" /etc/ssh/sshd_config
 
RUN  apt-get install -y python vim curl
 
CMD /usr/sbin/sshd -D && tail -f /var/log/wtmp

hight起来，light weight baby!