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How does docker images build its own native mirror

  • 2020-06-12 11:18:06
  • OfStack

How does docker images build its own native mirror

Making the image native image requires the febootstrap tool. Note that in the centos7 series, this package is not included in the default source, but in the centos6 series, it is available by default.

Install febootstrap in centos6 


# yum install febootstrap -y
 The appropriate packages are installed: fakechroot-2.9-24.5.el6_1.1.x86_64.rpm
 ,  fakechroot-libs-2.9-24.5.el6_1.1.x86_64.rpm 
 fakeroot-1.12.2-22.2.el6.x86_64.rpm fakeroot-libs-1.12.2-22.2.el6.x86_64.rpm 
 febootstrap-supermin-helper-3.21-4.el6.x86_64.rpm
 And that will produce 1 A command febootstrap

Use febootstrap tools to build base images: 


#febootstrap -i bash -i wget -i yum -i iputils -i iproute centos6.8 centos6.8-doc http://mirrors.163.com/centos/6.8/os/x86_64/

Note that the -ES22en parameter represents the installation package, es23EN6.8 is the image version, centos6.8-ES26en is the directory where the image is generated, and url is the source address of the image.

The build is then completed and a base image is generated: 


# ls centos6.8-doc
bin boot dev etc home lib lib64 media mnt opt proc root sbin selinux srv sys tmp usr var

You can see that the generated centos6.8-ES35en directory already contains the basic file system for the linux system. Generating such a directory is essentially a basic linux image that needs to be packaged and distributed to the docker host and built into the corresponding docker image.

Import this image using the docker tool:

In whatever environment, first go to the centos6.8-ES48en directory and then import the mirror: 


# cd centos6.8-doc
# tar -c .|docker import - centos:6.8
f86315da0e5ddfdbc2aaf169d7f26cf9e071afb7df04bc207ff0d5b623221c8c
 At this point, we have alpha 1 A mirror. 
# docker images
REPOSITORY              TAG         IMAGE ID      CREATED       VIRTUAL SIZE
centos                6.8         f86315da0e5d    6 seconds ago    392.9 MB

Next, use this image to create and use containers: 


# docker run -itd -P centos:6.8 bash
45fc3313c92f8ef8b1fe841da580ca0759b82e54a507c3985dc1c65d6106e12d
# docker ps -a 
CONTAINER ID    IMAGE            COMMAND       CREATED       STATUS       PORTS         NAMES
45fc3313c92f    centos:6.8          "bash"       20 seconds ago   Up 19 seconds               desperate_meitner

# docker exec -it desperate_meitner cat /etc/redhat-release 
CentOS release 6.8 (Final) 
 You can see the current image The mirror is created at that time 6.8 Version of the 

# docker exec -it desperate_meitner ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
  inet6 ::1/128 scope host 
    valid_lft forever preferred_lft forever
311: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP 
  link/ether 02:42:0a:00:00:25 brd ff:ff:ff:ff:ff:ff
  inet 10.0.0.37/24 scope global eth0
    valid_lft forever preferred_lft forever
  inet6 fe80::42:aff:fe00:25/64 scope link 
    valid_lft forever preferred_lft forever

At this point, a complete basic docker images is ready.

Thank you for reading, I hope to help you, thank you for your support to this site!

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