コンテナからの Docker イメージ作成

1. コンテナをシェルで実行する

code:shell

$ docker run -i -t centos /bin/bash

Unable to find image 'centos:latest' locally

latest: Pulling from library/centos

aeb7866da422: Pull complete

Digest: sha256:67dad89757a55bfdfabec8abd0e22f8c7c12a1856514726470228063ed86593b

Status: Downloaded newer image for centos:latest

root@5aeee6cee1b1 /#

2. コンテナ内でアプリケーションインストール

yum update

code:shell

root@5aeee6cee1b1 /# yum -y update

Apache HTTP Server install

code:shell

root@5aeee6cee1b1 /# yum -y install httpd

抜ける

コンテナ確認

code:shell

$ docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

5aeee6cee1b1 centos "/bin/bash" 8 minutes ago Exited (0) 3 seconds ago priceless_villani

3. コンテナから Docker イメージを作成する

作成

code:shell

$ docker commit 5aeee6cee1b1 centos-apache-http

sha256:c93287a7ebdf46eacd0035c23b5056450f34be3a7e12964597eb6b74dec4b798

Docker イメージ確認

code:shell

$ docker images

REPOSITORY TAG IMAGE ID CREATED SIZE

centos-apache-http latest c93287a7ebdf 47 seconds ago 334MB

(snip)

動作確認

code:shell

$ docker run centos-apache-http httpd -V

AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 172.17.0.2. Set the 'ServerName' directive globally to suppress this message

Server version: Apache/2.4.6 (CentOS)

Server built: Jun 27 2018 13:48:59

Server's Module Magic Number: 20120211:24

Server loaded: APR 1.4.8, APR-UTIL 1.5.2

Compiled using: APR 1.4.8, APR-UTIL 1.5.2

Architecture: 64-bit

Server MPM: prefork

threaded: no

forked: yes (variable process count)

Server compiled with....

-D APR_HAS_SENDFILE

-D APR_HAS_MMAP

-D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)

-D APR_USE_SYSVSEM_SERIALIZE

-D APR_USE_PTHREAD_SERIALIZE

-D SINGLE_LISTEN_UNSERIALIZED_ACCEPT

-D APR_HAS_OTHER_CHILD

-D AP_HAVE_RELIABLE_PIPED_LOGS

-D DYNAMIC_MODULE_LIMIT=256

-D HTTPD_ROOT="/etc/httpd"

-D SUEXEC_BIN="/usr/sbin/suexec"

-D DEFAULT_PIDLOG="/run/httpd/httpd.pid"

-D DEFAULT_SCOREBOARD="logs/apache_runtime_status"

-D DEFAULT_ERRORLOG="logs/error_log"

-D AP_TYPES_CONFIG_FILE="conf/mime.types"

-D SERVER_CONFIG_FILE="conf/httpd.conf"

#Docker