製作docker 鏡像的方法有很多個，下面介紹利用配置yum源來製作docker 鏡像的方法，以centos 7爲例
1） 配置yum源：將下載的CentOS-7-x86_64-DVD-1611.iso,掛載在／mnt，製作yum源。
# mount -o loop CentOS-7-x86_64-DVD-1611.iso /mnt
# cat /etc/yum.repos.d/centos7.repo
[centos7]
name=cetnos7
baseurl=file:///mnt
enabled=1
gpgcheck=0
2) 製作操作系統基礎鏡像，運行如下腳本即可：
#sh mk.sh
mk.sh [OPTIONS] <name>
OPTIONS:
-p "<packages>" The list of packages to install in the container.
The default is blank.
-g "<groups>" The groups of packages to install in the container.
The default is "Core".
-y <yumconf> The path to the yum config to install packages from. The
default is /etc/yum.conf for Centos/RHEL and /etc/dnf/dnf.conf for Fedora
mk.sh 腳本內容如下：
#!/usr/bin/env bash
#
# Create a base CentOS Docker image.
#
# This script is useful on systems with yum installed (e.g., building
# a CentOS image on CentOS). See contrib/mkimage-rinse.sh for a way
# to build CentOS images on other systems.
set -e
usage() {
cat <<EOOPTS
$(basename $0) [OPTIONS] <name>
OPTIONS:
-p "<packages>" The list of packages to install in the container.
The default is blank.
-g "<groups>" The groups of packages to install in the container.
The default is "Core".
-y <yumconf> The path to the yum config to install packages from. The
default is /etc/yum.conf for Centos/RHEL and /etc/dnf/dnf.conf for Fedora
EOOPTS
exit 1
}
# option defaults
yum_config=/etc/yum.conf
if [ -f /etc/dnf/dnf.conf ] && command -v dnf &> /dev/null; then
yum_config=/etc/dnf/dnf.conf
alias yum=dnf
fi
install_groups="Core"
while getopts ":y:p:g:h" opt; do
case $opt in
y)
yum_config=$OPTARG
;;
h)
usage
;;
p)
install_packages="$OPTARG"
;;
g)
install_groups="$OPTARG"
;;
\?)
echo "Invalid option: -$OPTARG"
usage
;;
esac
done
shift $((OPTIND - 1))
name=$1
if [[ -z $name ]]; then
usage
fi
target=$(mktemp -d --tmpdir $(basename $0).XXXXXX)
set -x
mkdir -m 755 "$target"/dev
mknod -m 600 "$target"/dev/console c 5 1
mknod -m 600 "$target"/dev/initctl p
mknod -m 666 "$target"/dev/full c 1 7
mknod -m 666 "$target"/dev/null c 1 3
mknod -m 666 "$target"/dev/ptmx c 5 2
mknod -m 666 "$target"/dev/random c 1 8
mknod -m 666 "$target"/dev/tty c 5 0
mknod -m 666 "$target"/dev/tty0 c 4 0
mknod -m 666 "$target"/dev/urandom c 1 9
mknod -m 666 "$target"/dev/zero c 1 5
# amazon linux yum will fail without vars set
if [ -d /etc/yum/vars ]; then
mkdir -p -m 755 "$target"/etc/yum
cp -a /etc/yum/vars "$target"/etc/yum/
fi
if [[ -n "$install_groups" ]];
then
yum -c "$yum_config" --installroot="$target" --releasever=/ --setopt=tsflags=nodocs \
--setopt=group_package_types=mandatory -y groupinstall "$install_groups"
fi
if [[ -n "$install_packages" ]];
then
yum -c "$yum_config" --installroot="$target" --releasever=/ --setopt=tsflags=nodocs \
--setopt=group_package_types=mandatory -y install "$install_packages"
fi
yum -c "$yum_config" --installroot="$target" -y clean all
cat > "$target"/etc/sysconfig/network <<EOF
NETWORKING=yes
HOSTNAME=localhost.localdomain
EOF
# effectively: febootstrap-minimize --keep-zoneinfo --keep-rpmdb --keep-services "$target".
# locales
rm -rf "$target"/usr/{{lib,share}/locale,{lib,lib64}/gconv,bin/localedef,sbin/build-locale-archive}
# docs and man pages
rm -rf "$target"/usr/share/{man,doc,info,gnome/help}
# cracklib
rm -rf "$target"/usr/share/cracklib
# i18n
rm -rf "$target"/usr/share/i18n
# yum cache
rm -rf "$target"/var/cache/yum
mkdir -p --mode=0755 "$target"/var/cache/yum
# sln
rm -rf "$target"/sbin/sln
# ldconfig
rm -rf "$target"/etc/ld.so.cache "$target"/var/cache/ldconfig
mkdir -p --mode=0755 "$target"/var/cache/ldconfig
version=
for file in "$target"/etc/{redhat,system}-release
do
if [ -r "$file" ]; then
version="$(sed 's/^[^0-9\]*\([0-9.]\+\).*$/\1/' "$file")"
break
fi
done
if [ -z "$version" ]; then
echo >&2 "warning: cannot autodetect OS version, using '$name' as tag"
version=$name
fi
tar --numeric-owner -c -C "$target" . | docker import - $name:$version
docker run -i -t --rm $name:$version /bin/bash -c 'echo success'
rm -rf "$target"
install_groups="Core"
while getopts ":y:p:g:h" opt; do
case $opt in
y)
yum_config=$OPTARG
;;
h)
usage
;;
p)
install_packages="$OPTARG"
;;
g)
install_groups="$OPTARG"
;;
\?)
echo "Invalid option: -$OPTARG"
usage
;;
esac
done
shift $((OPTIND - 1))
name=$1
if [[ -z $name ]]; then
usage
fi
target=$(mktemp -d --tmpdir $(basename $0).XXXXXX)
set -x
mkdir -m 755 "$target"/dev
mknod -m 600 "$target"/dev/console c 5 1
mknod -m 600 "$target"/dev/initctl p
mknod -m 666 "$target"/dev/full c 1 7
mknod -m 666 "$target"/dev/null c 1 3
mknod -m 666 "$target"/dev/ptmx c 5 2
mknod -m 666 "$target"/dev/random c 1 8
mknod -m 666 "$target"/dev/tty c 5 0
mknod -m 666 "$target"/dev/tty0 c 4 0
mknod -m 666 "$target"/dev/urandom c 1 9
mknod -m 666 "$target"/dev/zero c 1 5
# amazon linux yum will fail without vars set
if [ -d /etc/yum/vars ]; then
mkdir -p -m 755 "$target"/etc/yum
cp -a /etc/yum/vars "$target"/etc/yum/
fi
if [[ -n "$install_groups" ]];
then
yum -c "$yum_config" --installroot="$target" --releasever=/ --setopt=tsflags=nodocs \
--setopt=group_package_types=mandatory -y groupinstall "$install_groups"
fi
if [[ -n "$install_packages" ]];
then
yum -c "$yum_config" --installroot="$target" --releasever=/ --setopt=tsflags=nodocs \
--setopt=group_package_types=mandatory -y install "$install_packages"
fi
yum -c "$yum_config" --installroot="$target" -y clean all
cat > "$target"/etc/sysconfig/network <<EOF
NETWORKING=yes
HOSTNAME=localhost.localdomain
EOF
# effectively: febootstrap-minimize --keep-zoneinfo --keep-rpmdb --keep-services "$target".
# locales
rm -rf "$target"/usr/{{lib,share}/locale,{lib,lib64}/gconv,bin/localedef,sbin/build-locale-archive}
# docs and man pages
rm -rf "$target"/usr/share/{man,doc,info,gnome/help}
# cracklib
rm -rf "$target"/usr/share/cracklib
# i18n
rm -rf "$target"/usr/share/i18n
# yum cache
rm -rf "$target"/var/cache/yum
mkdir -p --mode=0755 "$target"/var/cache/yum
# sln
rm -rf "$target"/sbin/sln
# ldconfig
rm -rf "$target"/etc/ld.so.cache "$target"/var/cache/ldconfig
mkdir -p --mode=0755 "$target"/var/cache/ldconfig
version=
for file in "$target"/etc/{redhat,system}-release
do
if [ -r "$file" ]; then
version="$(sed 's/^[^0-9\]*\([0-9.]\+\).*$/\1/' "$file")"
break
fi
done
if [ -z "$version" ]; then
echo >&2 "warning: cannot autodetect OS version, using '$name' as tag"
version=$name
fi
tar --numeric-owner -c -C "$target" . | docker import - $name:$version
docker run -i -t --rm $name:$version /bin/bash -c 'echo success'
rm -rf "$target"
3） 利用docker file製作特製鏡像
# cat dockerfile
# 選擇一個已有的os鏡像作爲基礎
FROM 10.1.110.45/ns74/ns74-build09
USER root
# 鏡像的作者
MAINTAINER jian.hou "[email protected]"
# 設置時區
ENV TZ=Asia/Shanghai
# 安裝openssh-server和sudo軟件包，並且將sshd的UsePAM參數設置成no
#RUN yum install -y openssh-server sudo
#RUN sed -i 's/UsePAM yes/UsePAM no/g' /etc/ssh/sshd_config
# 添加測試用戶admin，密碼admin，並且將此用戶添加到sudoers裏
#RUN useradd admin
#RUN echo "admin:admin" | chpasswd
RUN echo "root:qwer1234" | chpasswd # 修改root密碼
#RUN echo "admin ALL=(ALL) ALL" >> /etc/sudoers
# 下面這兩句比較特殊，在centos6上必須要有，否則創建出來的容器sshd不能登錄
#RUN ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key
#RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
RUN echo "23 23 * * * sh /root/build.sh" > /var/spool/cron/root
RUN echo "touch /root/a.txt" > /root/build.sh
# 啓動sshd服務並且暴露22端口
#RUN mkdir /var/run/sshd
#EXPOSE 22
#CMD ["/usr/sbin/sshd", "-D"]
# 配置crond進程
RUN mkdir /var/run/crond
CMD ["/usr/sbin/crond", "-n"]
# docker build -t cetnos7-crond:v1 .
這樣就能構建出需要的docker鏡像cetos7-crond:v1
4) 將已有的docker環境轉化爲image，以上面的cetos7-crond:v1爲例子：
# docker run -it cento7-crond:v1 /bin/bash
# docker commit -m "centos7" -a "jian.hou" 35be4199aac7
sha256:9a8cc4ba1046dsfadsfadsfasdfadsfa
# docker images
# docker tag 9a8cc4ba1046d cento7-crond:v2