On this post today, i will write about an easy way to install docker on ubuntu 20.04. Docker is an application that simplifies the process of managing application processes in containers. Containers let you run your applications in resource-isolated processes.
Reference: https://docs.docker.com/engine/install/ubuntu/
Prerequisites
OS requirements to install Docker Engine, you need the 64-bit version of one of these Ubuntu versions:
- Hirsute 21.04
- Focal 20.04 (LTS)
- Bionic 18.04 (LTS)
Docker Engine is supported on x86_64
(or amd64
), armhf
, arm64
, and s390x
architectures.
Uninstall old versions
Older versions of Docker were called docker
, docker.io
, or docker-engine
. If these are installed, uninstall them:
$ sudo apt-get remove docker docker-engine docker.io containerd runc
It’s OK if apt-get
reports that none of these packages are installed.
Install using the repository
Install Docker Engine for the first time on a new host, we need to set up the Docker repository on ubuntu server.
In this post, we will install and update Docker from the repository.
Set up the repository
- Update the
apt
package index and install packages to allowapt
to use a repository over HTTPS:
$ sudo apt-get update
$ sudo apt-get install apt-transport-https ca-certificates curl gnupg lsb-release
2. Add Docker’s official GPG key:
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
3. Follow the command below to set up the stable repository. Add the nightly or test repository, add the word nightly
or test
(or both) after the word stable
in the commands below.
$ echo \
"deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
Install Docker Engine
- Update the
apt
package index, and install the latest version of Docker Engine and containerd, or go to the next step to install a specific version:
$ sudo apt-get update
$ sudo apt-get install docker-ce docker-ce-cli containerd.io
After installaton finished, let make sure service container docker is running well.
sudo systemctl status docker
2. To install a specific version of Docker Engine, please see show list the available versions in the repo result.
a. List the versions available in your repo:
$ apt-cache madison docker-ce
b. Install a specific version using the version string from the second column, for example, 5:18.09.1~3-0~ubuntu-xenial
.
sudo apt-get install docker-ce=<VERSION_STRING> docker-ce-cli=<VERSION_STRING> containerd.io
3. Verify that Docker Engine is installed correctly by running the hello-world
image.
$ sudo docker run hello-world
This command downloads a test image and runs it in a container. After the container runs, it prints a message and exits.
Yeay, congrats. Finally our docker is running now.