How to Install Docker on Ubuntu
As you may know, Docker allows you to pack, ship and run any application as a lightweight container. It’s like a virtual machine, only more portable and resources-efficient. This tutorial is going to show you how to install Docker on Ubuntu.
Requirements of Installing Docker on Ubuntu
You must be using a 64 bits OS because Docker doesn’t support 32 bits.
Install Docker from Ubuntu Repository
Docker is included in Ubuntu software repository. We can install the Docker runtime by executing the following command in terminal. This works on any current Ubuntu versions, including Ubuntu 16.04, Ubuntu 18.04, Ubuntu 19.10, Ubuntu 20.04.
sudo apt install docker.io
During the installation, a docker
group and a Systemd service will be created. You can check the systemd service with:
systemctl status containerd
Sample output:
● containerd.service - containerd container runtime Loaded: loaded (/lib/systemd/system/containerd.service; enabled; vendor preset: enabled) Active: active (running) since Tue 2020-04-21 09:32:38 HKT; 1min 45s ago Docs: https://containerd.io Main PID: 2035184 (containerd) Tasks: 11 Memory: 22.2M CGroup: /system.slice/containerd.service └─2035184 /usr/bin/containerd
Install Docker on Ubuntu from Docker’s APT Repository
The upstream Docker repository currently supports Ubuntu 16.04, Ubuntu 18.04 and Ubuntu 19.10.
To ensure that we have the latest and greatest version, we will have to install it from Docker’s APT repository. Run the following command to add Docker repository to your Ubuntu system.
echo "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list
Next, run the following command to import the Docker GPG key to Ubuntu system so that APT can verify package integrity during installation.
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
And because this repository uses HTTPS connection, which I recommend all software repositories should be using, we also need to install apt-transport-https
and ca-certificates
package.
sudo apt install apt-transport-https ca-certificates
Finally, update the package index on your Ubuntu system and install docker-ce
(Docker Community Edition).
sudo apt update sudo apt install docker-ce
Some Simple Commands You May Want to Run After Installing Docker
Once Docker is installed, the Docker daemon should be automatically started. You can check its status with:
systemctl status docker
If it’s not running, then start the daemon with this command:
sudo systemctl start docker
And enable autostart at boot time:
sudo systemctl enable docker
Check Docker version.
docker -v
Sample output:
Docker version 19.03.8, build afacb8b7f0
Display system-wide information regarding the Docker installation.
sudo docker info
Output:
Client: Debug Mode: false Server: Containers: 0 Running: 0 Paused: 0 Stopped: 0 Images: 0 Server Version: 19.03.8 Storage Driver: overlay2 Backing Filesystem: <unknown> Supports d_type: true Native Overlay Diff: true Logging Driver: json-file Cgroup Driver: cgroupfs 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: runc Default Runtime: runc Init Binary: docker-init containerd version: runc version: init version: Security Options: apparmor seccomp Profile: default Kernel Version: 5.4.0-21-generic Operating System: Ubuntu 20.04 LTS OSType: linux Architecture: x86_64 CPUs: 2 Total Memory: 7.776GiB Name: focal ID: 6WTB:ZCUU:BBET:XA2C:7OAP:WPWZ:N5OR:CFD6:Z32V:GJWE:D5VW:PYEG Docker Root Dir: /var/lib/docker Debug Mode: false Registry: https://index.docker.io/v1/ Labels: Experimental: false Insecure Registries: 127.0.0.0/8 Live Restore Enabled: false WARNING: No swap limit support
Verify Docker is installed correctly.
sudo docker run hello-world
You should see the following message indicating that Docker is working correctly.
Hello from Docker! This message shows that your installation appears to be working correctly.
Wrapping Up
I hope this tutorial helped you install Docker on Ubuntu. As always, if you found this post useful, then subscribe to our free newsletter.
Accurate, easy to follow tutorial. Thanks for putting this together!