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Docker on RockyLinux

This tutorial is good for starting with docker on rockylinux-9

Install docker repo as root with priority=50

dnf config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

dnf install docker-ce docker-ce-cli containerd.io

systemctl start docker
systemctl status docker
systemctl enable docker

Add your username to docker group

usermod -aG docker $USER

Download and install hub-tool

cd /tmp
wget https://github.com/docker/hub-tool/releases/download/v0.4.6/hub-tool-linux-amd64.tar.gz
tar -xvf hub-tool-linux-amd64.tar.gz
mv hub-tool hub-tool-v0.4.6
mv /tmp/hub-tool-v0.4.6  /opt
chown -Rv root:root /opt/hub-tool-v0.4.6
chcon -u system_u -t usr_t -Rv /opt/hub-tool-v0.4.6

Add hub-tool to your PATH

emacs ~/.bashrc.d/bash_aliases
export PATH=/opt/hub-tool-v0.4.6:$PATH

Docker has a good help online

docker
docker search --help

Per default you don't have any local images

docker images
REPOSITORY              TAG       IMAGE ID       CREATED        SIZE

Run the docker "Hello World" example

docker run hello-world

Show docker disk usage

docker system df

Search for RockyLinux images on Docker Hub

docker search rockylinux

Setup hub-tool with a docker account

hub-tool --version
hub-tool login

user=*
pass=*

List all tags of rockylinux/rockylinux

hub-tool tag ls --sort updated rockylinux/rockylinux

TAG                                       DIGEST                            STATUS    LAST UPDATE      LAST PUSHED    LAST PULLED       SIZE
rockylinux/rockylinux:9-minimal           sha256:9e67a934b74b8fe2ef9d...    active    2 months ago     2 months       22 minutes        241.4MB
rockylinux/rockylinux:9.5                 sha256:531a9a14d0e640d32f61...    active    2 months ago     2 months       51 seconds        348.7MB
rockylinux/rockylinux:8                   sha256:f514765516176a9aa472...    active    8 months ago     8 months       About a minute    151.8MB
rockylinux/rockylinux:8.10-minimal        sha256:55ddcbe11a7bf1696f67...    active    8 months ago     8 months       7 minutes         76.57MB
rockylinux/rockylinux:8.10                sha256:f514765516176a9aa472...    active    8 months ago     8 months       About a minute    151.8MB

Download an image

docker pull rockylinux/rockylinux:9.5

A second pull will check if a download is really necessary

docker pull rockylinux/rockylinux:9.5
9.5: Pulling from rockylinux/rockylinux
Digest: sha256:149fd31d916038eb1084d0e051537e279d7afcd5de0b365254e8fa3c3ef12bad
Status: Image is up to date for rockylinux/rockylinux:9.5
docker.io/rockylinux/rockylinux:9.5

Create a new container and install some packages

docker run -it rockylinux/rockylinux:9.5

[root@c779d77f7557 /]#

dnf install epel-release
dnf install htop ncurses file vim-minmal
exit

Create an image from container c779d77f7557

docker commit -m "generic container" -a "Mihai Vasilian" c779d77f7557 mihai-repo/rocky-9

List local images

docker images
REPOSITORY              TAG       IMAGE ID       CREATED         SIZE
mihai-repo/rocky-9      latest    aa5326bfb9df   2 minutes ago   344MB
hello-world             latest    74cc54e27dc4   2 weeks ago     10.1kB
rockylinux/rockylinux   9.5       bb8a97547d22   2 months ago    234MB

List local containers

CONTAINER ID   IMAGE                       COMMAND       CREATED          STATUS                       PORTS     NAMES
c54574f205f8   hello-world                 "/hello"      11 minutes ago   Exited (0) 11 minutes ago              festive_mirzakhani
c779d77f7557   rockylinux/rockylinux:9.5   "/bin/bash"   26 minutes ago   Exited (137) 6 minutes ago             busy_hamilton

How to use container c779d77f7557

docker start    c779d77f7557         : start in detached mode
docker stop     c779d77f7557         : stop a container
docker restart  c779d77f7557         : restart in detached mode
docker exec -it c779d77f7557 bash    : execute a command in a running container

Remove container c54574f205f8 (hello-world)

docker rm c54574f205f8

Remove image 74cc54e27dc4 (hello-world)

docker rmi 74cc54e27dc4

Untagged: hello-world:latest
Untagged: hello-world@sha256:d715f14f9eca81473d9112df50457893aa4d099adeb4729f679006bf5ea12407
Deleted: sha256:74cc54e27dc41bb10dc4b2226072d469509f2f22f1a3ce74f4a59661a1d44602
Deleted: sha256:63a41026379f4391a306242eb0b9f26dc3550d863b7fdbb97d899f6eb89efe72
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