一、需求
由於在測試環境中使用了docker官網的centos 鏡像，但是該鏡像里面默認沒有安裝ssh服務，在做測試時又需要開啟ssh。所以上網也查了查資料。下面詳細的紀錄下。在centos 容器內安裝ssh后，轉成新的鏡像用於后期測試使用。
二、鏡像定制
第一種方式（手動修改容器鏡像）
1.先下載centos鏡像
[root@docker ~]# docker pull centos
2.啟動容器並進行配置
啟動容器，
[root@docker ~]# docker run -it -d --name test-centos1 centos
d72250ecaa5e3e36226a1edd749f494d9f00eddc4143c81ac3565aa4e551791a
命令注釋：-it : 進行交互式操作
-d : 等同於 -d=true,容器將會在后台運行，不然執行一次命令后，退出后，便是exit狀態了。
--name : 容器啟動后的名字，默認不指定，將會隨機產生一個名字。或者使用 -name="containers_name"
centos：使用的鏡像名稱
進入容器，安裝ssh server，以及配置開機啟動
[root@docker ~]# docker exec -it test-centos1 /bin/bash [root@d72250ecaa5e /]# ifconfig bash: ifconfig: command not found
注：命令最后參數 /bin/bash： 指進入容器時執行的命令（command）原文來自：飛走不可 ^_^ http://www.cnblogs.com/hanyifeng/p/6116067.html
我們檢查了下容器，暫時安裝以下必用的軟件吧 net-tools，openssh-server
[root@d72250ecaa5e /]# yum install openssh-server net-tools -y
創建ssh 所需的目錄，並在根目錄創建sshd 啟動腳本
[root@d72250ecaa5e /]# mkdir -pv /var/run/sshd mkdir: created directory '/var/run/sshd'
[root@d72250ecaa5e /]# cat /auto_sshd.sh #!/bin/bash /usr/sbin/sshd -D [root@d72250ecaa5e /]# chmod +x /auto_sshd.sh
修改容器內root 的賬戶密碼
[root@d72250ecaa5e /]# echo "root:iloveworld" | chpasswd
生成ssh 主機dsa 密鑰（不然ssh 該容器時，會出現錯誤。）
[root@d72250ecaa5e /]# ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key [root@d72250ecaa5e /]# ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
我們加一個history記錄的時間功能吧，這樣方便后期查看
echo 'export HISTTIMEFORMAT="%F %T `whoami` "' >> /etc/profile
OK，配置基本完畢咯。清理命令歷史紀錄，之后退出容器。現在可以生成一個新的docker 鏡像了。
3.配置完成后，進行打包成新的鏡像
[root@docker ~]# docker commit test-centos1 centos_sshd:7.0 sha256:6e3330b30dfff5f029f102874e54cfffffbc37dcf2a4eb7304c817148fbc944d
[root@docker ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE centos_sshd 7.0 6e3330b30dff 8 seconds ago 310.1 MB docker.io/ubuntu latest e4415b714b62 12 days ago 128.1 MB
命令注釋：commit： 提交一個具有新配置的容器成為鏡像，后面跟容器的name 或者容器Id ，最后是生成新鏡像的名字
更新：這條命令更方便以后啟動，如下：
[root@docker ~]# docker commit --change='CMD ["/auto_sshd.sh"]' -c "EXPOSE 22" test-centos1 centos_sshd:7.0 sha256:7bb4efd82c4ff1f241cbc57ee45aab1b05d214b1e9fcd51196696c67d480e70b
命令注釋： --change : 將后期使用此鏡像運行容器時的命令參數、開放的容器端口提前設置好。
4.驗證
查看鏡像，並啟動新的容器
[root@docker ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE centos_sshd 7.0 7bb4efd82c4f 4 minutes ago 310.1 MB docker.io/ubuntu latest e4415b714b62 12 days ago 128.1 MB [root@docker ~]# docker run -d -it --name centos_7.0-1 centos_sshd:7.0 ec17e553d5c4c60865afeb99df8dfd1f4e7d4ba6e1b0d5516f9127f09d1d6356 [root@docker ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES ec17e553d5c4 centos_sshd:7.0 "/auto_sshd.sh" 6 seconds ago Up 5 seconds 22/tcp centos_7.0-1
進行ssh測試，先查看一下該容器的ip，之后ssh。ok
[root@docker ~]# docker exec centos_7.0-1 hostname -i 172.17.0.4 [root@docker ~]# ssh root@172.17.0.4 The authenticity of host '172.17.0.4 (172.17.0.4)' can't be established. RSA key fingerprint is 87:88:07:12:ac:0a:90:28:10:e1:9e:eb:1f:d6:c9:9d. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '172.17.0.4' (RSA) to the list of known hosts. root@172.17.0.4's password: Last login: Tue Nov 29 16:00:49 2016 from gateway [root@ec17e553d5c4 ~]# w 16:34:17 up 63 days, 7:49, 1 user, load average: 0.00, 0.02, 0.05 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 gateway 16:34 1.00s 0.00s 0.00s w [root@ec17e553d5c4 ~]# ping gateway PING gateway (172.17.0.1) 56(84) bytes of data. 64 bytes from gateway (172.17.0.1): icmp_seq=1 ttl=64 time=0.048 ms
第二種方式（推薦：利用Dockerfile文件）
我的認為它就像ansible的playbook一樣。Dockerfile包含創建鏡像所需要的全部指令。基於在Dockerfile中的指令，我們可以使用Docker build命令來創建鏡像。通過減少鏡像和容器的創建過程來簡化部署。
1.創建Dockerfile文件
新建一個目錄，在里面新建一個dockerfile文件（新建一個的目錄，主要是為了和以防和其它dockerfile混亂 ）
[root@docker ~]# mkdir centos7-dockerfile [root@docker centos7-dockerfile]# cat Dockerfile # The dockerfile has Change add sshd services on Centos7.0 #centos7:latest image FROM centos:latest MAINTAINER Yifeng,http://www.cnblogs.com/hanyifeng #Install sshd net-tools RUN yum install openssh-server net-tools -y RUN mkdir /var/run/sshd #Set password for root RUN echo 'root:iloveworld' | chpasswd RUN sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config #Set history record ENV HISTTIMEFORMAT "%F %T " #Fix sshd service:Read from socket failed: Connection reset by peer? RUN ssh-keygen -A #Change timezone CST RUN \cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime #Open 22 port EXPOSE 22 #Auto running sshd service CMD ["/usr/sbin/sshd","-D"]
上述文件內容就是一個dockerfile 常見的命令組合。開頭帶＃號的為注釋
原文來自：飛走不可 ^_^ http://www.cnblogs.com/hanyifeng/p/6116067.html
文件解釋：
FROM： 必不可少的命令，從某個鏡像作為基。如 FROM <image_name> ，或者 FROM <image_name>:<tag>. 如果不加tag，默認為latest。先從本地鏡像倉庫去搜索基鏡像，如過本地沒有，在去網上docker registry去尋找。
MAINTAINER：標明該Dockerfile作者及聯系方式，可忽略不寫
RUN：建立新的鏡像時，可以執行在系統里的命令，如安裝特定的軟件以及設置環境變量。
ENV：設置系統環境變量（注意：寫在/etc/profile里的命令在dockerfile這里會不生效，所以為改成ENV的方式）
EXPOSE：開放容器內的端口，但不和宿主機進行映射。方便在宿主機上進行開發測試。（如需映射到宿主機端口，可在運行容器時使用 -p host_port:container_port）
CMD：設置執行的命令，經常用於容器啟動時指定的某個操作。如執行自定義腳本服務，或者是執行系統命令。CMD 只能存在一條，如在Dockerfile中有多條CMD的話，只有最后一條CMD生效！
2.執行build 創建鏡像
使用docker build命令來創建鏡像
[root@docker centos7-dockerfile]# docker build -t centos_sshd_1 .
-t 選項來docker build新的鏡像以便於標記構建的鏡像，. 表示當前目錄，也可以指定dockerfile 文件所在目錄。
下面縮略的內容是構建鏡像時的輸出，可以看下。
[root@docker centos7-dockerfile]# docker build -t centos_sshd_1 . Sending build context to Docker daemon 4.096 kB Step 1 : FROM centos:latest ---> 0584b3d2cf6d Step 2 : MAINTAINER Yifeng,http://www.cnblogs.com/hanyifeng ---> Running in da643b55dc77 ---> 1087074d44e4 Removing intermediate container da643b55dc77 Step 3 : RUN yum install openssh-server net-tools -y ---> Running in 5626d8f0f892 Loaded plugins: fastestmirror, ovl Determining fastest mirrors * base: mirrors.btte.net * extras: mirrors.tuna.tsinghua.edu.cn * updates: mirrors.btte.net Resolving Dependencies --> Running transaction check ---> Package net-tools.x86_64 0:2.0-0.17.20131004git.el7 will be installed ---> Package openssh-server.x86_64 0:6.6.1p1-25.el7_2 will be installed --> Processing Dependency: openssh = 6.6.1p1-25.el7_2 for package: openssh-server-6.6.1p1-25.el7_2.x86_64 --> Processing Dependency: fipscheck-lib(x86-64) >= 1.3.0 for package: openssh-server-6.6.1p1-25.el7_2.x86_64 --> Processing Dependency: libwrap.so.0()(64bit) for package: openssh-server-6.6.1p1-25.el7_2.x86_64 --> Processing Dependency: libfipscheck.so.1()(64bit) for package: openssh-server-6.6.1p1-25.el7_2.x86_64 --> Running transaction check ---> Package fipscheck-lib.x86_64 0:1.4.1-5.el7 will be installed --> Processing Dependency: /usr/bin/fipscheck for package: fipscheck-lib-1.4.1-5.el7.x86_64 ---> Package openssh.x86_64 0:6.6.1p1-25.el7_2 will be installed ---> Package tcp_wrappers-libs.x86_64 0:7.6-77.el7 will be installed --> Running transaction check ---> Package fipscheck.x86_64 0:1.4.1-5.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: net-tools x86_64 2.0-0.17.20131004git.el7 base 304 k openssh-server x86_64 6.6.1p1-25.el7_2 updates 436 k Installing for dependencies: fipscheck x86_64 1.4.1-5.el7 base 21 k fipscheck-lib x86_64 1.4.1-5.el7 base 11 k openssh x86_64 6.6.1p1-25.el7_2 updates 435 k tcp_wrappers-libs x86_64 7.6-77.el7 base 66 k Transaction Summary ================================================================================ Install 2 Packages (+4 Dependent packages) Total download size: 1.2 M Installed size: 3.4 M Downloading packages: Public key for fipscheck-lib-1.4.1-5.el7.x86_64.rpm is not installed warning: /var/cache/yum/x86_64/7/base/packages/fipscheck-lib-1.4.1-5.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY Public key for openssh-6.6.1p1-25.el7_2.x86_64.rpm is not installed -------------------------------------------------------------------------------- Total 593 kB/s | 1.2 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-7-2.1511.el7.centos.2.10.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-1.4.1-5.el7.x86_64 1/6 Installing : fipscheck-lib-1.4.1-5.el7.x86_64 2/6 Installing : openssh-6.6.1p1-25.el7_2.x86_64 3/6 Installing : tcp_wrappers-libs-7.6-77.el7.x86_64 4/6 Installing : openssh-server-6.6.1p1-25.el7_2.x86_64 5/6 Installing : net-tools-2.0-0.17.20131004git.el7.x86_64 6/6 Verifying : openssh-6.6.1p1-25.el7_2.x86_64 1/6 Verifying : openssh-server-6.6.1p1-25.el7_2.x86_64 2/6 Verifying : net-tools-2.0-0.17.20131004git.el7.x86_64 3/6 Verifying : tcp_wrappers-libs-7.6-77.el7.x86_64 4/6 Verifying : fipscheck-lib-1.4.1-5.el7.x86_64 5/6 Verifying : fipscheck-1.4.1-5.el7.x86_64 6/6 Installed: net-tools.x86_64 0:2.0-0.17.20131004git.el7 openssh-server.x86_64 0:6.6.1p1-25.el7_2 Dependency Installed: fipscheck.x86_64 0:1.4.1-5.el7 fipscheck-lib.x86_64 0:1.4.1-5.el7 openssh.x86_64 0:6.6.1p1-25.el7_2 tcp_wrappers-libs.x86_64 0:7.6-77.el7 Complete! ---> 7b249ed8cb54 Removing intermediate container 5626d8f0f892 Step 4 : RUN mkdir /var/run/sshd ---> Running in fc94a139d438 ---> ea2826eccc91 Removing intermediate container fc94a139d438 Step 5 : RUN echo 'root:iloveworld' | chpasswd ---> Running in ba53283081a7 ---> 7ce1ddb5d9c0 Removing intermediate container ba53283081a7 Step 6 : RUN sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config ---> Running in 4112281a5bf0 ---> be21fb6b5b1e Removing intermediate container 4112281a5bf0 Step 7 : ENV HISTTIMEFORMAT "%F %T " ---> Running in f2081726e403 ---> f3fafca42170 Removing intermediate container f2081726e403 Step 8 : RUN ssh-keygen -A ---> Running in 2ca9e743dee7 ssh-keygen: generating new host keys: RSA1 RSA DSA ECDSA ED25519 ---> 1a927943bee7 Removing intermediate container 2ca9e743dee7 Step 9 : RUN \cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime ---> Running in afd43cc6d4d6 ---> 4a0cacf6cd72 Removing intermediate container afd43cc6d4d6 Step 10 : EXPOSE 22 ---> Running in a03551bc3bcb ---> 3af544106bf4 Removing intermediate container a03551bc3bcb Step 11 : CMD /usr/sbin/sshd -D ---> Running in f45fe5eb5561 ---> d4620c9949b8 Removing intermediate container f45fe5eb5561 Successfully built d4620c9949b8
3.查看鏡像列表，並創建容器
[root@docker centos7-dockerfile]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE centos_sshd_1 latest d4620c9949b8 4 minutes ago 308.4 MB centos_sshd 7.0 7bb4efd82c4f 2 days ago 310.1 MB
我們剛剛新建的容器已經存在了，現在用它來創建容器
[root@docker centos7-dockerfile]# docker run -d -it --name centos-two centos_sshd_1 7ae51091c138d249b5e97f6957073e748db278c0f1cf856e968ca78a4aec1a5b
查看容器 [root@docker centos7-dockerfile]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7ae51091c138 centos_sshd_1 "/usr/sbin/sshd -D" 16 seconds ago Up 15 seconds 22/tcp centos-two
👌，可以看到容器的command 就是我們之前定義啟動ssh 服務的，並且開放了22端口。
現在我們在宿主機上查看下該容器的ip，然后用ssh 鏈接進去。
[root@docker ~]# docker exec centos-two hostname -I 172.17.0.7 [root@docker ~]# ssh root@172.17.0.7 The authenticity of host '172.17.0.7 (172.17.0.7)' can't be established. ECDSA key fingerprint is 7a:38:69:d7:5e:f4:db:e8:3c:ea:92:a4:1a:a1:7b:9a. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '172.17.0.7' (ECDSA) to the list of known hosts. root@172.17.0.7's password: [root@7ae51091c138 ~]# w 11:19:34 up 65 days, 18:34, 1 user, load average: 0.01, 0.04, 0.05 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 gateway 11:19 6.00s 0.00s 0.00s w
OK。上述就是定義鏡像的兩種方式，如果還有其它更為方便的還望不吝賜教哈。
新手在路上...
注:該文屬於飛走不可原創，如有轉載，請務必在文首注明出處。飛走不可 ^_^ http://www.cnblogs.com/hanyifeng/p/6116067.html
參考鏈接：
http://serverfault.com/questions/583355/ssh-issues-read-from-socket-failed-connection-reset-by-peer
http://blog.octo.com/en/openshift-3-private-paas-with-docker/
https://docs.docker.com/engine/examples/running_ssh_service/
https://docs.docker.com/engine/tutorials/dockerimages/