Docker中怎么构建SSH镜像

基于commit命令方式创建

docker的安装

[root@test01 ~]# yum install docker[root@test01 ~]# systemctl enable docker[root@test01 ~]# systemctl start docker

下载本地镜像

使用docker run命令时，Docker会自动的先查找本地的镜像，如果没有找到，会继续向docker hub上查找并下载。我习惯先下载下来docker pull centos 默认本系统版本的最新版，如果指定版本，加上冒号和版本号

[root@test01 ~]# docker pull centos:7.4.1708[root@test01 ~]# docker imagesREPOSITORY          TAG                 IMAGE ID            CREATED             SIZEdocker.io/centos    7.4.1708            3afd47092a0e        3 months ago        196.6 MB

创建交互型容器

[root@test01 ~]# docker run -it --name="ssh_server" centos:7.4.1708 /bin/bash[root@ffe61e183a6c /]#

安装必要的服务

通过yum安装，检查yum源配置是否正确，centos7的默认和主机的一样

yum install openssh-server 安装ssh服务程序yum install net-tools 安装网络工具，用来查看端口，可不安装[root@ffe61e183a6c /]# yum install openssh-server net-tools

配置sshserver服务

使用ssh-keygen生成必要的密钥

[root@ffe61e183a6c /]# ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key[root@ffe61e183a6c /]# ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key[root@ffe61e183a6c /]# ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key

启动ssh服务器，并查看是否启动成功

/usr/sbin/sshd -D &

此处的-D参数用于告诉SSH服务不以守护进程运行，而是和运行终端关联，有了运行终端，容器就不会退出

[root@ffe61e183a6c /]# /usr/sbin/sshd -D &[1] 82[root@ffe61e183a6c /]# netstat -tunplaActive Internet connections (servers and established)Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      82/sshd            tcp6       0      0 :::22                   :::*                    LISTEN      82/sshd[root@ffe61e183a6c /]# pkill sshd

编写SSH运行脚本

至此，我们可以证实ssh服务启动没有问题，接下来我们编写启动脚本，用于启动容器的时候运行，因为容器启动时只能运行一个命令，一般这个命令用来启动脚本

[root@ffe61e183a6c ~]# cat run.sh#!/bin/bash/usr/sbin/sshd -D[root@ffe61e183a6c ~]# chmod 775 run.sh

提交生成的镜像

使用docker commit将刚才的容器提交为一个新的镜像

[root@ffe61e183a6c ~]# exitexit[root@test01 ~]#[root@test01 ~]# docker ps -aCONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMESffe61e183a6c        centos:7.4.1708     "/bin/bash"         19 minutes ago      Exited (0) 8 seconds ago                       ssh_server[root@test01 ~]# docker commit ffe61e183a6c ssh:commitsha256:be55c135e6141481aff3218b7a269b27d8f0faa295ed244849bf8ccf7ad1c7b1[root@test01 ~]# docker imagesREPOSITORY          TAG                 IMAGE ID            CREATED             SIZEssh                 commit              be55c135e614        11 seconds ago      296.5 MBdocker.io/centos    7.4.1708            3afd47092a0e        3 months ago        196.6 MB

启动镜像

[root@test01 ~]# docker run -d -p 2022:22 ssh:commit /root/run.sh6d5628a2a336bc302fa45baf6e6a1d5ade2f6dd42a4697553c6e3dda1a0a3226[root@test01 ~]# docker psCONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                  NAMES6d5628a2a336        ssh:commit          "/root/run.sh"      8 seconds ago       Up 6 seconds        0.0.0.0:2022->22/tcp   prickly_bell

补漏

刚才忘记给docker镜像设置密码了，这次需要给设置一下密码

[root@test01 ~]# docker ps -aCONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                       PORTS               NAMES6d5628a2a336        ssh:commit          "/root/run.sh"      6 minutes ago       Exited (137) 4 minutes ago                       prickly_bellffe61e183a6c        centos:7.4.1708     "/bin/bash"         29 minutes ago      Exited (0) 9 minutes ago                         ssh_server[root@test01 ~]# docker run -it ssh:commit /bin/bash[root@0204e7257a24 /]# passwd rootChanging password for user root.New password:Retype new password:passwd: all authentication tokens updated successfully.[root@0204e7257a24 /]# exitexit[root@test01 ~]# docker ps -aCONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                       PORTS               NAMES0204e7257a24        ssh:commit          "/bin/bash"         29 seconds ago      Exited (0) 4 seconds ago                         trusting_borg6d5628a2a336        ssh:commit          "/root/run.sh"      9 minutes ago       Exited (137) 7 minutes ago                       prickly_bellffe61e183a6c        centos:7.4.1708     "/bin/bash"         32 minutes ago      Exited (0) 12 minutes ago                        ssh_server[root@test01 ~]# docker commit 0204e7257a24 ssh02:commitsha256:b92a3cde4c9162cf12ac9cf61a61ce0332d3755b7708e4037c4df09b4e794177

再次启动需改后的镜像

[root@test01 ~]# docker run -d -p 2022:22 ssh02:commit /root/run.sh357ed4074c5d7f1ec1fe0df6af9c9a3162c70fa5624f7742bf59f309d9842247

验证是否成功

[root@test01 ~]# ssh root@192.168.1.60 -p2022root@192.168.1.60's password:[root@357ed4074c5d ~]# exit[root@test01 ~]# docker stop 357ed4074c5d

基于Dockerfile方式创建

准备文件

创建一个存放生成镜像相关文件的目录

该目录下需要创建2个文件：Dockerfile、run.sh。Dockerfile用于构建镜像，run.sh是启动SSH服务的脚本

mkdir ssh_dockerfile && cd ssh_dockerfile

编写Dockerfile、run.sh

[root@test01 ssh_dockerfile]# cat Dockerfile#使用的基础镜像FROM centos:7.4.1708#添加作者信息MAINTAINER liuxin 842887233@qq.com#安装SSH服务RUN yum install -y openssh-server#添加必要的密钥RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_keyRUN ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_keyRUN ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key#添加启动文件ADD run.sh /root/run.shRUN chmod 775 /root/run.sh#导出端口EXPOSE 22#设置默认启动命令CMD ["/root/run.sh"][root@test01 ssh_dockerfile]# cat run.sh#!/bin/bash/usr/sbin/sshd -D

创建镜像

[root@test01 ssh_dockerfile]# docker build ./Sending build context to Docker daemon 3.072 kBStep 1 : FROM centos:7.4.1708---> 3afd47092a0eStep 2 : MAINTAINER liuxin 842887233@qq.com---> Using cache---> bd64810df0bcStep 3 : RUN yum install -y openssh-server---> Using cache---> 5dc6301a0304Step 4 : RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key---> Using cache---> 0ce92e5baa9fStep 5 : RUN ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key---> Using cache---> fcb2bcf78ea0Step 6 : RUN ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key---> Using cache---> 7eae01e47ee2Step 7 : ADD run.sh /root/run.sh---> 4d07a723ffcfRemoving intermediate container 0b137a9274beStep 8 : RUN chmod 775 /root/run.sh---> Running in 1d5a9524da86---> 324868eb5780Removing intermediate container 1d5a9524da86Step 9 : EXPOSE 22---> Running in ada62bb87978---> a0b3df156e21Removing intermediate container ada62bb87978Step 10 : CMD /root/run.sh---> Running in 4f5031577ff4---> 8679c00088efRemoving intermediate container 4f5031577ff4Successfully built 8679c00088ef[root@test01 ssh_dockerfile]# docker imagesREPOSITORY          TAG                 IMAGE ID            CREATED              SIZE                           8679c00088ef        About a minute ago   295.9 MBssh02               commit              b92a3cde4c91        55 minutes ago       296.5 MBssh                 commit              be55c135e614        About an hour ago    296.5 MBdocker.io/centos    7.4.1708            3afd47092a0e        3 months ago         196.6 MB

运行镜像

[root@test01 ssh_dockerfile]# docker run -d -p 2022:22 8679c00088efe73a441afc8df35f42a30974c8697278fe6d35c1ac711d13ec817e74ffbf4008[root@test01 ssh_dockerfile]# docker psCONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                  NAMESe73a441afc8d        8679c00088ef        "/root/run.sh"      14 seconds ago      Up 12 seconds       0.0.0.0:2022->22/tcp   fervent_yonath