Docker

Managing Docker Containers on Ubuntu 20.04

Mohammad Hossein Khoshraftar Yari

Today, I want to install the Docker on Ubuntu 20.04.

Content:

1- What is Docker and its use case?
2- Set up Docker's apt repository
3- Install the Docker packages
4- Verify installation

1- What is Docker and its use case?

Docker is an application that simplifies the process of managing application processes in containers. Containers let you run your applications in resource-isolated processes. They’re similar to virtual machines, but containers are more portable, more resource-friendly, and more dependent on the host operating system.

Prerequisites

  • One Ubuntu 20.04 server
  • An account on Docker Hub if you wish to create your images and push them to Docker Hub

Installing Using the apt repository

We must ensure we get the latest version, we’ll install Docker from the official Docker repository. To do that, we’ll add a new package source, add the GPG key from Docker to ensure the downloads are valid, then install the package.

1- Set up Docker’s apt repository.

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

2- Install the Docker packages.

 sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

3- Verify installation

Verify that the Docker Engine installation is successful by running the hello-world image.

 sudo docker run hello-world

Note:

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.