コンテナで Cent OS を稼働させてカスタムイメージを作成する
Cent OS のイメージを取得してコンテナを作成して実行
$ sudo docker search centos
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
centos The official build of CentOS. 3759 [OK]
ansible/centos7-ansible Ansible on Centos7 103 [OK]
jdeathe/centos-ssh CentOS-6 6.9 x86_64 / CentOS-7 7.4.1708 x8... 88 [OK]
tutum/centos Simple CentOS docker image with SSH access 33
imagine10255/centos6-lnmp-php56 centos6-lnmp-php56 31 [OK]
gluster/gluster-centos Official GlusterFS Image [ CentOS-7 + Glu... 21 [OK]
kinogmt/centos-ssh CentOS with SSH 17 [OK]
openshift/base-centos7 A Centos7 derived base image for Source-To... 11
centos/php-56-centos7 Platform for building and running PHP 5.6 ... 10
centos/python-35-centos7 Platform for building and running Python 3... 9
openshift/jenkins-2-centos7 A Centos7 based Jenkins v2.x image for use... 6
openshift/mysql-55-centos7 DEPRECATED: A Centos7 based MySQL v5.5 ima... 6
darksheer/centos Base Centos Image -- Updated hourly 3 [OK]
openshift/ruby-20-centos7 DEPRECATED: A Centos7 based Ruby v2.0 imag... 3
blacklabelops/centos CentOS Base Image! Built and Updates Daily! 1 [OK]
openshift/php-55-centos7 DEPRECATED: A Centos7 based PHP v5.5 image... 1
pivotaldata/centos-gpdb-dev CentOS image for GPDB development. Tag nam... 1
pivotaldata/centos-mingw Using the mingw toolchain to cross-compile... 1
miko2u/centos6 CentOS6 日本語環境 1 [OK]
indigo/centos-maven Vanilla CentOS 7 with Oracle Java Developm... 1 [OK]
pivotaldata/centos-gcc-toolchain CentOS with a toolchain, but unaffiliated ... 0
openshift/wildfly-101-centos7 A Centos7 based WildFly v10.1 image for us... 0
pivotaldata/centos Base centos, freshened up a little with a ... 0
smartentry/centos centos with smartentry 0 [OK]
jameseckersall/sonarr-centos Sonarr on CentOS 7 0 [OK]
$ curl -s https://registry.hub.docker.com/v2/repositories/library/centos/tags/ | grep -Po '"name":.*?[^//]",'
"name": "7",
"name": "centos7",
"name": "latest",
"name": "7.4.1708",
"name": "centos7.4.1708",
"name": "6.8",
"name": "centos6.8",
"name": "6.9",
"name": "centos6.9",
"name": "7.2.1511",今回は centos:centos7 を用いてコンテナを作成。docker run の後、自動的にプロンプトがコンテナイメージ上のものに遷移する。なお、シェルのような対話的なプログラムをコンテナ内で実行させるためには -it オプションをつける。
$ sudo docker run -it centos:centos7 /bin/bash
Unable to find image 'centos:centos7' locally
centos7: Pulling from library/centos
d9aaf4d82f24: Pull complete
Digest: sha256:eba772bac22c86d7d6e72421b4700c3f894ab6e35475a34014ff8de74c10872e
Status: Downloaded newer image for centos:centos7
[root@bf6ff4d6487d /]# uname -a
Linux bf6ff4d6487d 4.9.51-10.52.amzn1.x86_64 #1 SMP Fri Sep 29 01:16:19 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
[root@bf6ff4d6487d /]# ls /etc
BUILDTIME bash_completion.d dbus-1 gcrypt hosts ld.so.cache machine-id os-release printcap rc1.d rpm shells systemd yum.conf
DIR_COLORS bashrc default gnupg hosts.allow ld.so.conf modprobe.d pam.d profile rc2.d rsyslog.d skel terminfo yum.repos.d
DIR_COLORS.256color binfmt.d depmod.d group hosts.deny ld.so.conf.d modules-load.d passwd profile.d rc3.d sasl2 ssl tmpfiles.d
DIR_COLORS.lightbgcolor centos-release dracut.conf group- init.d libaudit.conf motd passwd- protocols rc4.d securetty subgid udev
GREP_COLORS centos-release-upstream dracut.conf.d gshadow inputrc libuser.conf mtab pkcs11 python rc5.d security subuid vconsole.conf
X11 chkconfig.d environment gshadow- issue locale.conf nsswitch.conf pki qemu-ga rc6.d selinux sysconfig virc
adjtime.rpmsave crypttab exports gss issue.net localtime nsswitch.conf.bak pm rc.d redhat-release services sysctl.d xdg
aliases csh.cshrc filesystems host.conf krb5.conf login.defs openldap popt.d rc.local resolv.conf shadow system-release xinetd.d
alternatives csh.login fstab hostname krb5.conf.d logrotate.d opt prelink.conf.d rc0.d rpc shadow- system-release-cpe yum
[root@bf6ff4d6487d /]# yum update
[root@bf6ff4d6487d /]# yum upgrade
[root@bf6ff4d6487d /]# yum install emacs -y
[root@bf6ff4d6487d /]# exit
exitこれで emacs がインストールされ、exit で bash が終了し、コンテナも停止する。
コンテナからイメージを作成
docker commit を用いてコンテナからイメージを作成する。今回は先ほど emacs をインストールしたコンテナから新たなイメージを作成する。イメージ名は centos7-emacs-installed とする。
$ sudo docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
bf6ff4d6487d centos:centos7 "/bin/bash" 8 minutes ago Exited (0) About a minute ago competent_nightingale
9ae657fb11fd httpd:2.4.29 "httpd-foreground" 15 minutes ago Up 15 minutes 0.0.0.0:8080->80/tcp sharp_cray
50413563b304 httpd:2.4.29 "httpd-foreground" 26 minutes ago Exited (0) 16 minutes ago dreamy_goldstine
$ sudo docker commit bf6ff4d6487d centos:centos7-emacs-installed
sha256:fb048d27b6966bb08ae09185e06c17ca46c82a14f878c02e47d965cc524f5cc5
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos centos7-emacs-installed fb048d27b696 11 seconds ago 557 MB
httpd 2.4.29 a8bdc7fdaa4f 7 days ago 177 MB
centos centos7 196e0ce0c9fb 6 weeks ago 197 MBイメージが作成されたことが確認できる。
実際に作成したイメージからコンテナを作成する。
$ sudo docker run -it centos:centos7-emacs-installed /bin/bash
[root@d2330054030c /]# emacs --version
GNU Emacs 24.3.1
Copyright (C) 2013 Free Software Foundation, Inc.
GNU Emacs comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of Emacs
under the terms of the GNU General Public License.
For more information about these matters, see the file named COPYING.emacs がインストールされていることがわかる。