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@silveraid
Created October 27, 2017 12:09
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Creating minimal CentOS docker image from scratch
# Create a folder for our new root structure
$ export centos_root='/centos_image/rootfs'
$ mkdir -p $centos_root
# initialize rpm database
$ rpm --root $centos_root --initdb
# download and install the centos-release package, it contains our repository sources
$ yum reinstall --downloadonly --downloaddir . centos-release
$ rpm --root $centos_root -ivh centos-release*.rpm
$ rpm --root $centos_root --import $centos_root/etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
# install yum without docs and install only the english language files during the process
$ yum -y --installroot=$centos_root --setopt=tsflags='nodocs' --setopt=override_install_langs=en_US.utf8 install yum
# configure yum to avoid installing of docs and other language files than english generally
$ sed -i "/distroverpkg=centos-release/a override_install_langs=en_US.utf8\ntsflags=nodocs" $centos_root/etc/yum.conf
# chroot to the environment and install some additional tools
$ cp /etc/resolv.conf $centos_root/etc
$ chroot $centos_root /bin/bash <<EOF
yum install -y procps-ng iputils
yum clean all
EOF
$ rm -f $centos_root/etc/resolv.conf
# install and enable docker
$ yum install -y docker
...
$ systemctl start docker
# create docker image
$ tar -C $centos_root -c . | docker import - centos
sha256:28843acfa85226385d2db0196db72465729db38088ea98751d4a5c3d4c85ccd
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos latest 28843acfa852 11 seconds ago 287.7 MB
# run docker image
$ docker run --rm centos cat /etc/redhat-release
CentOS Linux release 7.2.1511 (Core)
Source: https://www.sidorenko.io/post/2016/07/creating-container-base-image-of-centos/
@nileshkumar008
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[root@localhost ~]# chroot $centos_root /bin/bash <<EOF
yum install -y procps-ng iputils
yum clean all
EOF
error: Failed to initialize NSS library
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

cannot import name ts

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.7.5 (default, Apr 2 2020, 13:16:51)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)]

If you cannot solve this problem yourself, please go to
the yum faq at:
http://yum.baseurl.org/wiki/Faq

error: Failed to initialize NSS library
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

cannot import name ts

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.7.5 (default, Apr 2 2020, 13:16:51)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)]

If you cannot solve this problem yourself, please go to
the yum faq at:
http://yum.baseurl.org/wiki/Faq

@nileshkumar008
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mount -o bind /dev $centos_root/dev

issue has been resolved

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