How to Export and Import Docker Container on Rocky Linux 8.6

To Export and Import Docker Container on Rocky Linux 8.6

Introduction:

Docker is a platform as a service that delivers software in containers using OS-level virtualization, which enables you to build, test, and deploy applications quickly and easily.

Installation Procedure:

Step 1: Check the OS version by using the below command

[root@localhost ~]# cat /etc/os-release
NAME="Rocky Linux"
VERSION="8.6 (Green Obsidian)"
ID="rocky"
ID_LIKE="rhel centos fedora"
VERSION_ID="8.6"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Rocky Linux 8.6 (Green Obsidian)"
ANSI_COLOR="0;32"
CPE_NAME="cpe:/o:rocky:rocky:8:GA"
HOME_URL="https://rockylinux.org/"
BUG_REPORT_URL="https://bugs.rockylinux.org/"
ROCKY_SUPPORT_PRODUCT="Rocky Linux"
ROCKY_SUPPORT_PRODUCT_VERSION="8"
REDHAT_SUPPORT_PRODUCT="Rocky Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8"

Step 2: Pull the Ubuntu Docker Image from Docker Hub by using the below command

[root@localhost ~]# docker pull ubuntu
Using default tag: latest
latest: Pulling from library/ubuntu
d19f32bd9e41: Pull complete 
Digest: sha256:34fea4f31bf187bc915536831fd0afc9d214755bf700b5cdb1336c82516d154e
Status: Downloaded newer image for ubuntu:latest
docker.io/library/ubuntu:latest

Step 3: List the Docker Images by using the below command

[root@localhost ~]# docker images
REPOSITORY    TAG       IMAGE ID       CREATED         SIZE
ubuntu        latest    df5de72bdb3b   5 days ago      77.8MB
hello-world   latest    feb5d9fea6a5   10 months ago   13.3kB

Step 4: Run a Container from Ubuntu Docker Image by using the below command

[root@localhost ~]# docker run -dit ubuntu
def73521f6034b0e951d57591cd459d5091b03f628ae8040b023c35c69a881bd

Step 5: Check the Running Containers by using the below command

[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED          STATUS          PORTS     NAMES
def73521f603   ubuntu    "bash"    14 seconds ago   Up 11 seconds             stoic_lichterman

Step 6: Login to the Container Shell by using the below command

[root@localhost ~]# docker exec -it stoic_lichterman /bin/bash

Step 7: Update the APT source List

root@def73521f603:/# apt update
Get:1 http://security.ubuntu.com/ubuntu jammy-security InRelease [110 kB]
Get:2 http://archive.ubuntu.com/ubuntu jammy InRelease [270 kB]
Get:3 http://archive.ubuntu.com/ubuntu jammy-updates InRelease [114 kB]
Get:4 http://archive.ubuntu.com/ubuntu jammy-backports InRelease [99.8 kB]
Get:5 http://archive.ubuntu.com/ubuntu jammy/main amd64 Packages [1792 kB]
Get:6 http://archive.ubuntu.com/ubuntu jammy/restricted amd64 Packages [164 kB]                    
Get:7 http://archive.ubuntu.com/ubuntu jammy/multiverse amd64 Packages [266 kB]                    
Get:8 http://archive.ubuntu.com/ubuntu jammy/universe amd64 Packages [17.5 MB]                     
0% [8 Packages 17.0 MB/17.5 MB 97%]                                                     290 kB/s 1s
0% [8 Packages 17.2 MB/17.5 MB 99%]                                                     290 kB/s 0s
Reading package lists... Done                                                                      
E: Release file for http://security.ubuntu.com/ubuntu/dists/jammy-security/InRelease is not valid yet (invalid for another 43min 44s). Updates for this repository will not be applied.
E: Release file for http://archive.ubuntu.com/ubuntu/dists/jammy-updates/InRelease is not valid yet (invalid for another 43min 50s). Updates for this repository will not be applied.
E: Release file for http://archive.ubuntu.com/ubuntu/dists/jammy-backports/InRelease is not valid yet (invalid for another 44min 10s). Updates for this repository will not be applied.

Step 8: Install tree Package for testing purpose by using the below command

root@def73521f603:/# apt install tree -y
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
  tree
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 47.9 kB of archives.
After this operation, 116 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu jammy/universe amd64 tree amd64 2.0.2-1 [47.9 kB]
Fetched 47.9 kB in 1s (45.1 kB/s)
debconf: delaying package configuration, since apt-utils is not installed
Selecting previously unselected package tree.
(Reading database ... 4395 files and directories currently installed.)
Preparing to unpack .../tree_2.0.2-1_amd64.deb ...
Unpacking tree (2.0.2-1) ...
Setting up tree (2.0.2-1) ...

Step 9: Exit from the Container by using the below command

root@def73521f603:/# exit
exit

Step 10: Check the Running Containers by using the below command

[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED         STATUS         PORTS     NAMES
def73521f603   ubuntu    "bash"    3 minutes ago   Up 3 minutes             stoic_lichterman

Step 11: Export the Running Container as tar file by using the below command

[root@localhost ~]# docker export --output="tree.tar" stoic_lichterman 

Step 12: List the exported Image by using the below command

[root@localhost ~]# ls -la
total 110416
dr-xr-x---. 16 root root      4096 Aug  7 14:05 .
dr-xr-xr-x. 17 root root       224 Jun 27 08:39 ..
-rw-------.  1 root root      1204 Jun 27 08:48 anaconda-ks.cfg
-rw-------.  1 root root       115 Jun 27 03:23 .bash_history
-rw-r--r--.  1 root root        18 Mar 14  2021 .bash_logout
-rw-r--r--.  1 root root       176 Mar 14  2021 .bash_profile
-rw-r--r--.  1 root root       129 Mar 14  2021 .tcshrc
drwxr-xr-x.  2 root root         6 Jun 27 08:50 Templates
-rw-------.  1 root root 113016832 Aug  7 14:05 tree.tar
drwxr-xr-x.  2 root root         6 Jun 27 08:50 Videos
-rw-------.  1 root root       134 Jul 22 02:39 .Xauthority

Step 13: Import the Exported Container, The Exported Container is imported as Docker Image then need to run the Containers from the Image by using the below command

[root@localhost ~]# docker import tree.tar
sha256:8ec36daac21660ae60192578d850b4dd681ea6addf99106fec107d4df1b58e52

Step 14: List the Docker Images by using the below command

root@localhost ~]# docker images
REPOSITORY    TAG       IMAGE ID       CREATED          SIZE
<none>        <none>    8ec36daac216   22 seconds ago   110MB
ubuntu        latest    df5de72bdb3b   5 days ago       77.8MB
hello-world   latest    feb5d9fea6a5   10 months ago    13.3kB

Step 15: Run a Container from the Imported Docker Image by using the below command

[root@localhost ~]# docker run -it 8ec36daac216 /bin/bash

Step 16: Check the Package installed before exporting by using the below command

root@6c5b9045e4cd:/# apt list --installed |grep tree


WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

tree/jammy,now 2.0.2-1 amd64 [installed]

Conclusion:

We have reached the end of this article. In this guide, we have walked you through the steps required to Export and Import Docker Container on Rocky Linux 8.6. Your feedback is much welcome.