前面使用commit的方式，制作一个docker镜像，本次介绍使用Dockerfile制作一个dockers镜像
[root@docker-server3 ~]# mkdir /openssh
[root@docker-server3 ~]# cd /openssh
[root@docker-server3 openssh]# cp /etc/ssh/ssh_host_ecdsa_key /etc/ssh/ssh_host_ed25519_key /etc/ssh/ssh_host_rsa_key .
[root@docker-server3 openssh]# ll
-rw-r----- 1 root root 227 Dec 31 13:13 ssh_host_ecdsa_key -rw-r----- 1 root root 387 Dec 31 13:13 ssh_host_ed25519_key -rw-r----- 1 root root 1679 Dec 31 13:13 ssh_host_rsa_key
1 编辑Dockerfile文件
[root@docker-server3 openssh]# vim Dockerfile
FROM centos:7 LABEL darren darren@gmail.com RUN yum -y install openssh-server && useradd natash && echo "redhat"|passwd --stdin natash && echo "redhat"|passwd --stdin root && ssh-keygen -q -t rsa -b 2048 -f /etc/ssh/ssh_host_rsa_key -N '' && ssh-keygen -q -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N '' && ssh-keygen -t dsa -f /etc/ssh/ssh_host_ed25519_key -N '' ADD ssh_host_ecdsa_key /tmp/ssh_host_ecdsa_key ADD ssh_host_ed25519_key /tmp/ssh_host_ed25519_key ADD ssh_host_rsa_key /tmp/ssh_host_rsa_key CMD ["/usr/sbin/sshd", "-D"]
FROM表示下载基本镜像
LABEL作者信息
RUN 表示要执行的动作，相当于执行脚本，执行的是/bin/sh -c ***的动作
ADD表示复制文件
CMD表示执行一个命令
2 使用docker build构建镜像
[root@docker-server3 openssh]# docker build -t openssh:v1.3 .
Sending build context to Docker daemon 7.168kB Step 1/7 : FROM centos:7 ---> 5e35e350aded Step 2/7 : LABEL darren darren@gmail.com ---> Running in e4326a6f6000 Removing intermediate container e4326a6f6000 ---> eb19f72c1afd Step 3/7 : RUN yum -y install openssh-server && useradd natash && echo "redhat"|passwd --stdin natash && echo "redhat"|passwd --stdin root && ssh-keygen -q -t rsa -b 2048 -f /etc/ssh/ssh_host_rsa_key -N '' && ssh-keygen -q -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N '' && ssh-keygen -t dsa -f /etc/ssh/ssh_host_ed25519_key -N '' ---> Running in 41b40d14da2d Loaded plugins: fastestmirror, ovl Determining fastest mirrors * base: mirror.pregi.net * extras: mirror.pregi.net * updates: mirror.pregi.net Resolving Dependencies --> Running transaction check ---> Package openssh-server.x86_64 0:7.4p1-21.el7 will be installed --> Processing Dependency: openssh = 7.4p1-21.el7 for package: openssh-server-7.4p1-21.el7.x86_64 --> Processing Dependency: fipscheck-lib(x86-64) >= 1.3.0 for package: openssh-server-7.4p1-21.el7.x86_64 --> Processing Dependency: libwrap.so.0()(64bit) for package: openssh-server-7.4p1-21.el7.x86_64 --> Processing Dependency: libfipscheck.so.1()(64bit) for package: openssh-server-7.4p1-21.el7.x86_64 --> Running transaction check ---> Package fipscheck-lib.x86_64 0:1.4.1-6.el7 will be installed --> Processing Dependency: /usr/bin/fipscheck for package: fipscheck-lib-1.4.1-6.el7.x86_64 ---> Package openssh.x86_64 0:7.4p1-21.el7 will be installed ---> Package tcp_wrappers-libs.x86_64 0:7.6-77.el7 will be installed --> Running transaction check ---> Package fipscheck.x86_64 0:1.4.1-6.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: openssh-server x86_64 7.4p1-21.el7 base 459 k Installing for dependencies: fipscheck x86_64 1.4.1-6.el7 base 21 k fipscheck-lib x86_64 1.4.1-6.el7 base 11 k openssh x86_64 7.4p1-21.el7 base 510 k tcp_wrappers-libs x86_64 7.6-77.el7 base 66 k Transaction Summary ================================================================================ Install 1 Package (+4 Dependent packages) Total download size: 1.0 M Installed size: 3.0 M Downloading packages: warning: /var/cache/yum/x86_64/7/base/packages/fipscheck-1.4.1-6.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY Public key for fipscheck-1.4.1-6.el7.x86_64.rpm is not installed -------------------------------------------------------------------------------- Total 446 kB/s | 1.0 MB 00:02 Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 Importing GPG key 0xF4A80EB5: Userid : "CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>" Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5 Package : centos-release-7-7.1908.0.el7.centos.x86_64 (@CentOS) From : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : fipscheck-1.4.1-6.el7.x86_64 1/5 Installing : fipscheck-lib-1.4.1-6.el7.x86_64 2/5 Installing : openssh-7.4p1-21.el7.x86_64 3/5 Installing : tcp_wrappers-libs-7.6-77.el7.x86_64 4/5 Installing : openssh-server-7.4p1-21.el7.x86_64 5/5 Verifying : fipscheck-lib-1.4.1-6.el7.x86_64 1/5 Verifying : tcp_wrappers-libs-7.6-77.el7.x86_64 2/5 Verifying : fipscheck-1.4.1-6.el7.x86_64 3/5 Verifying : openssh-7.4p1-21.el7.x86_64 4/5 Verifying : openssh-server-7.4p1-21.el7.x86_64 5/5 Installed: openssh-server.x86_64 0:7.4p1-21.el7 Dependency Installed: fipscheck.x86_64 0:1.4.1-6.el7 fipscheck-lib.x86_64 0:1.4.1-6.el7 openssh.x86_64 0:7.4p1-21.el7 tcp_wrappers-libs.x86_64 0:7.6-77.el7 Complete! Changing password for user natash. passwd: all authentication tokens updated successfully. Changing password for user root. passwd: all authentication tokens updated successfully. Generating public/private dsa 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: SHA256:7LIsGt0osRc9JoEYjake8YD1pTcynqoUbep/IK7T2Xs root@41b40d14da2d The key's randomart image is: +---[DSA 1024]----+ |o=. . | |+=.o o | |o = * o | |...o B o | |..oo= + S | | o+* * o | |.+*o= o . | |+oo+ooEo | |+oooo+o | +----[SHA256]-----+ Removing intermediate container 41b40d14da2d ---> 2be613021085 Step 4/7 : ADD ssh_host_ecdsa_key /tmp/ssh_host_ecdsa_key ---> c64f7dcda4c1 Step 5/7 : ADD ssh_host_ed25519_key /tmp/ssh_host_ed25519_key ---> 86e57a7a4313 Step 6/7 : ADD ssh_host_rsa_key /tmp/ssh_host_rsa_key ---> 2412a6e26b9c Step 7/7 : CMD ["/usr/sbin/sshd", "-D"] ---> Running in e3e2df3ee1c8 Removing intermediate container e3e2df3ee1c8 ---> 0244c59bf444 Successfully built 0244c59bf444 Successfully tagged openssh:v1.3
每一个step都会生成一个镜像层
在生成镜像层后，docker会自动识别，看是否有必要存在这个镜像层，如果没有必要，就会删除这个镜像层，如第二步：
Step 2/7 : LABEL darren darren@gmail.com ---> Running in e4326a6f6000 Removing intermediate container e4326a6f6000
3 查看镜像
发现新的镜像openssh:v1.3
[root@docker-server3 openssh]# docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE openssh v1.3 0244c59bf444 42 seconds ago 306MB openssh v1.2 c399a750ed03 2 hours ago 361MB openssh v1.0 d98ba06569f3 2 hours ago 361MB nginx latest f7bb5701a33c 3 days ago 126MB busybox latest 6d5fcfe5ff17 4 days ago 1.22MB hub.darren.com/library/alpine 3.7 cc0abc535e36 7 days ago 5.59MB centos 7 5e35e350aded 7 weeks ago 203MB
4 运行一个容器
[root@docker-server3 openssh]# docker run -d openssh:v1.3
fd2c629a2b3c067ecfa6ff601bf5a158f16087d40b16487e514688a125ab8f70
[root@docker-server3 openssh]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES fd2c629a2b3c openssh:v1.3 "/usr/sbin/sshd -D" 13 seconds ago Up 13 seconds
5 测试容器，检查镜像是否达到要求
[root@docker-server3 openssh]# docker inspect fd2c629a2b3c |grep IP
"LinkLocalIPv6Address": "", "LinkLocalIPv6PrefixLen": 0, "SecondaryIPAddresses": null, "SecondaryIPv6Addresses": null, "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0, "IPAddress": "192.168.0.2", "IPPrefixLen": 24, "IPv6Gateway": "", "IPAMConfig": null, "IPAddress": "192.168.0.2", "IPPrefixLen": 24, "IPv6Gateway": "", "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0,
ssh连接，测试openssh，并查看copy的文件
[root@docker-server3 openssh]# ssh root@192.168.0.2
The authenticity of host '192.168.0.2 (192.168.0.2)' can't be established. ECDSA key fingerprint is SHA256:j3tvwS9TpQzJVj3QN+SLescO3vpSiiT18bA1e12ZR+M. ECDSA key fingerprint is MD5:5c:cc:e9:cf:3d:b7:9c:d3:fe:93:50:b6:0f:f6:27:40. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.0.2' (ECDSA) to the list of known hosts. root@192.168.0.2's password: [root@fd2c629a2b3c ~]# ll /tmp/ssh* -rw-r----- 1 root root 227 Dec 31 18:13 /tmp/ssh_host_ecdsa_key -rw-r----- 1 root root 387 Dec 31 18:13 /tmp/ssh_host_ed25519_key -rw-r----- 1 root root 1679 Dec 31 18:13 /tmp/ssh_host_rsa_key [root@fd2c629a2b3c ~]# exit logout Connection to 192.168.0.2 closed.
[root@docker-server3 openssh]# ssh natash@192.168.0.2
natash@192.168.0.2's password: [natash@fd2c629a2b3c ~]$ exit logout Connection to 192.168.0.2 closed.
说明镜像制作完成，后续在研究学习关于Dockerfile的语法
博主声明：本文的内容来源主要来自誉天教育晏威老师，由本人实验完成操作验证，需要的博友请联系誉天教育（http://www.yutianedu.com/），获得官方同意或者晏老师（https://www.cnblogs.com/breezey/）本人同意即可转载，谢谢！