Introduction
In the ever-evolving landscape of modern software development and deployment, Docker has become an indispensable tool. Docker provides a streamlined way to package, distribute, and manage applications within isolated containers. In this step-by-step guide, we will walk you through the process of how to install Docker Community Edition (CE) on Rocky Linux 9. By the end of this article, you’ll have a solid foundation to utilize Docker for optimizing your development and deployment workflows.
Rocky Linux 9 operates on the foundation of an RHEL package-based distribution, while Docker serves as a commercial platform utilized by both individuals and businesses to establish and manage containers. As an open-source software, Docker offers a lightweight alternative to other Type-2 virtualization software, such as VirtualBox. Beyond the availability of pre-built images, it’s also possible to craft our own images for execution within containers powered by the Docker Engine.
For the execution of virtual containers, a system capable of supporting virtualization is required. Fortunately, most modern systems come with this capability enabled by default. However, if not, the manual configuration needs to be done through the BIOS settings.
Table of Contents
Prerequisites
Before we dive into the installation process, make sure you have the following prerequisites in place:
- A Rocky Linux 9 system with root or sudo access, you can deploy this on a physical machine or a virtual environment like VMware or VirtualBox. To set this up, follow our guide :
- A stable internet connection to download packages
- Basic familiarity with command-line operations.
Environment Specification:
We are using a minimal Rocky Linux 9 virtual machine with following specifications.
- CPU – 2 cores
- Memory – 2 GB
- Storage – 32 GB
- Operating System – Rocky Linux release 9.2 (Blue Onyx)
- Hostname – docker
- IP Address – 172.32.1.222/24
Install Docker CE on Rocky Linux 9
Follow these steps to install Docker CE on your Rocky Linux 9 and harness its powerful features for your containers:
Step 1: System Update
Refresh your cache for enabled yum repositories.
[samm@docker ~]$ sudo dnf makecache --refresh
Rocky Linux 9 - BaseOS 2.3 kB/s | 4.1 kB 00:01
Rocky Linux 9 - AppStream 3.0 kB/s | 4.5 kB 00:01
Rocky Linux 9 - CRB 3.5 kB/s | 4.5 kB 00:01
Rocky Linux 9 - Extras 1.0 kB/s | 2.9 kB 00:02
Metadata cache created.
[samm@docker ~]$ sudo dnf update -y
Step 2: Adding Docker repository
Community’s most favorite containerization software is available via Docker’s Official Yum Repository.
Enable the Docker CE repository by running the following command.
[samm@docker ~]$ sudo dnf config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo
Output:
Adding repo from: https://download.docker.com/linux/centos/docker-ce.repo
You have added a new yum repository, therefore, rebuild your yum cache again.
[samm@docker ~]$ sudo dnf makecache
Docker CE Stable - x86_64
Rocky Linux 9 - BaseOS 1.8 kB/s | 4.1 kB 00:02
Rocky Linux 9 - AppStream 2.2 kB/s | 4.5 kB 00:02
Rocky Linux 9 - CRB 3.1 kB/s | 4.5 kB 00:01
Rocky Linux 9 - Extras 3.3 kB/s | 2.9 kB 00:00
Metadata cache created.
Step 3: Installation of Docker-CE on Rocky Linux 9
With our Rocky Linux 9 system all set to receive the latest Docker packages, let’s proceed by using the terminal and the ‘dnf’ package manager to install them. The following command will get you started:
[samm@docker ~]$ sudo dnf install docker-ce docker-ce-cli containerd.io
Last metadata expiration check: 0:23:14 ago on Thu 27 Jul 2023 02:49:39 PM EDT.
Dependencies resolved.
===================================================================================================================================================================================================================
Package Architecture Version Repository Size
===================================================================================================================================================================================================================
Installing:
containerd.io x86_64 1.6.21-3.1.el9 docker-ce-stable 33 M
docker-ce x86_64 3:24.0.5-1.el9 docker-ce-stable 24 M
docker-ce-cli x86_64 1:24.0.5-1.el9 docker-ce-stable 7.1 M
Installing dependencies:
container-selinux noarch 3:2.205.0-1.el9_2 appstream 50 k
docker-ce-rootless-extras x86_64 24.0.5-1.el9 docker-ce-stable 3.9 M
fuse-overlayfs x86_64 1.11-1.el9_2 appstream 71 k
fuse3 x86_64 3.10.2-5.el9.0.1 appstream 53 k
fuse3-libs x86_64 3.10.2-5.el9.0.1 appstream 91 k
libslirp x86_64 4.4.0-7.el9 appstream 68 k
slirp4netns x86_64 1.2.0-3.el9 appstream 45 k
Installing weak dependencies:
docker-buildx-plugin x86_64 0.11.2-1.el9 docker-ce-stable 13 M
docker-compose-plugin x86_64 2.20.2-1.el9 docker-ce-stable 13 M
Transaction Summary
===================================================================================================================================================================================================================
Install 12 Packages
Total download size: 93 M
Installed size: 373 M
Enable and Start the Docker service.
[samm@docker-ce ~]$ sudo systemctl enable docker
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
[samm@docker ~]$ sudo systemctl start docker.service
[samm@docker ~]$ sudo systemctl status docker.service
● docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; preset: disabled)
Active: active (running) since Thu 2023-07-27 15:16:49 EDT; 30min ago
TriggeredBy: ● docker.socket
Docs: https://docs.docker.com
Main PID: 195439 (dockerd)
Tasks: 11
Memory: 36.7M
CPU: 431ms
CGroup: /system.slice/docker.service
└─195439 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
Jul 27 15:16:47 docker systemd[1]: Starting Docker Application Container Engine...
Jul 27 15:16:47 docker dockerd[195439]: time="2023-07-27T15:16:47.668338031-04:00" level=info msg="Starting up"
Jul 27 15:16:47 docker dockerd[195439]: time="2023-07-27T15:16:47.753811667-04:00" level=info msg="Loading containers: start."
Jul 27 15:16:49 docker dockerd[195439]: time="2023-07-27T15:16:49.033590056-04:00" level=info msg="Firewalld: interface docker0 already part of docker zone, returning"
Jul 27 15:16:49 docker dockerd[195439]: time="2023-07-27T15:16:49.177426451-04:00" level=info msg="Loading containers: done."
Jul 27 15:16:49 docker dockerd[195439]: time="2023-07-27T15:16:49.218304381-04:00" level=info msg="Docker daemon" commit=a61e2b4 graphdriver=overlay2 version=24.0.5
Jul 27 15:16:49 docker dockerd[195439]: time="2023-07-27T15:16:49.218491017-04:00" level=info msg="Daemon has completed initialization"
Jul 27 15:16:49 docker dockerd[195439]: time="2023-07-27T15:16:49.361917835-04:00" level=info msg="API listen on /run/docker.sock"
Jul 27 15:16:49 docker systemd[1]: Started Docker Application Container Engine.
[samm@docker ~]$ sudo systemctl is-enabled docker
enabled
[samm@docker ~]$ sudo systemctl is-active docker
active
Step 4: Check Docker Version
Verify that the Docker command is working fine by querying the version of you Containerization software.
[samm@docker ~]$ sudo docker version
Client: Docker Engine - Community
Version: 24.0.5
API version: 1.43
Go version: go1.20.6
Git commit: ced0996
Built: Fri Jul 21 20:36:54 2023
OS/Arch: linux/amd64
Context: default
Server: Docker Engine - Community
Engine:
Version: 24.0.5
API version: 1.43 (minimum version 1.12)
Go version: go1.20.6
Git commit: a61e2b4
Built: Fri Jul 21 20:35:17 2023
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.6.21
GitCommit: 3dce8eb055cbb6872793272b4f20ed16117344f8
runc:
Version: 1.1.7
GitCommit: v1.1.7-0-g860f061
docker-init:
Version: 0.19.0
GitCommit: de40ad0
[samm@docker ~]$ docker info
Client: Docker Engine - Community
Version: 24.0.5
Context: default
Debug Mode: false
Plugins:
buildx: Docker Buildx (Docker Inc.)
Version: v0.11.2
Path: /usr/libexec/docker/cli-plugins/docker-buildx
compose: Docker Compose (Docker Inc.)
Version: v2.20.2
Path: /usr/libexec/docker/cli-plugins/docker-compose
Server:
Containers: 1
Running: 0
Paused: 0
Stopped: 1
Images: 1
Server Version: 24.0.5
Storage Driver: overlay2
Backing Filesystem: xfs
Supports d_type: true
Using metacopy: false
Native Overlay Diff: true
userxattr: false
Logging Driver: json-file
Cgroup Driver: systemd
Cgroup Version: 2
Plugins:
Volume: local
Network: bridge host ipvlan macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: io.containerd.runc.v2 runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 3dce8eb055cbb6872793272b4f20ed16117344f8
runc version: v1.1.7-0-g860f061
init version: de40ad0
Security Options:
seccomp
Profile: builtin
cgroupns
Kernel Version: 5.14.0-284.11.1.el9_2.x86_64
Operating System: Rocky Linux 9.2 (Blue Onyx)
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 3.576GiB
Name: docker
ID: 498002d4-7673-4f62-b572-0b91c72d2954
Docker Root Dir: /var/lib/docker
Debug Mode: false
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
Step 5: Run Docker without sudo
The next task of ours in installing Docker on Rocky Linux 9 is to run it without sudo. By default, a user has to use sudo with every command of Docker to run it. Hence, we add our current user to its group to solve this.
[sudo usermod -aG docker $username]
[samm@docker ~]$ sudo usermod -aG docker samm
[samm@docker ~]$ sudo chmod 666 /var/run/docker.sock
Reload Shell session
[samm@docker ~]$ newgrp docker
Step 6: Testing Docker with a Test Image
The Linux environment is now prepared to generate containers featuring a range of Linux and application images. However, before proceeding, let’s verify its functionality to ensure that our configuration is accurate and error-free.
[samm@docker ~]$ docker run hello-world
The output will give a confirmation message – Hello from Docker
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
719385e32844: Pull complete
Digest: sha256:926fac19d22aa2d60f1a276b66a20eb765fbeea2db5dbdaafeb456ad8ce81598
Status: Downloaded newer image for hello-world:latest
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
Examples of Docker Command Usage
[samm@docker ~]$ docker search alpine --filter is-official=true
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
alpine A minimal Docker image based on Alpine Linux… 10142 [OK]
Pull Alpine Linux image from Docker Hub.
[samm@docker ~]$ docker pull alpine
Using default tag: latest
latest: Pulling from library/alpine
31e352740f53: Pull complete
Digest: sha256:82d1e9d7ed48a7523bdebc18cf6290bdb97b82302a8a9c27d4fe885949ea94d1
Status: Downloaded newer image for alpine:latest
docker.io/library/alpine:latest
List down the locally available container images on your Docker Host.
[samm@docker ~]$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
alpine latest c1aabb73d233 6 weeks ago 7.33MB
hello-world latest 9c7a54a9a43c 2 months ago 13.3kB
Step 7: Test Run Docker
Construct a container using the Alpine Linux image, then access a shell within it to perform various test commands.
[samm@docker ~]$ docker run -it --rm alpine /bin/sh
/ # cat /etc/os-release
NAME="Alpine Linux"
ID=alpine
VERSION_ID=3.18.2
PRETTY_NAME="Alpine Linux v3.18"
HOME_URL="https://alpinelinux.org/"
BUG_REPORT_URL="https://gitlab.alpinelinux.org/alpine/aports/-/issues"
/ # uname -r
5.14.0-284.11.1.el9_2.x86_64
/ # exit
Uninstall Docker CE (optional)
Only use these commands when you no longer need Docker on Rocky Linux 9. They will remove Docker, including all currently running containers managed by the service.
[samm@docker ~]$ sudo dnf remove -y docker-ce docker-ce-cli containerd.io
[samm@docker ~]$ sudo rm -rf /var/lib/docker
[samm@docker ~]$ sudo rm -rf /var/lib/containerd
Conclusion
Congratulations! You’ve successfully installed Docker CE on Rocky Linux 9. Docker opens up a world of possibilities for packaging, distributing, and managing applications effortlessly. You’re now ready to explore containerization and take advantage of the benefits it offers to modern software development. Whether you’re a developer, system administrator, or IT professional, Docker will undoubtedly enhance your workflow and make your life easier. Happy containerizing!
Also Read Our Other Guides :
- Install and Configure Docker Swarm Mode on Centos 7
- How To Install Docker CE on Centos 7
- How To Install and Use Docker Compose on Centos 7
- How To Install and Use Docker CE on Ubuntu 22.04
Hopefully, now you have learned how to install Docker CE on Rocky Linux 9.
