Docker Installation

What is Docker?

Docker is an open platform for developing, shipping, and running applications. Docker enables you to separate your applications from your infrastructure so you can deliver software quickly. With Docker, you can manage your infrastructure in the same ways you manage your applications.

What is Docker Container

A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application.
Containers are an abstraction at the app layer that packages code and dependencies together. Multiple containers can run on the same machine and share the OS kernel with other containers, each running as isolated processes in user space.

Lets start the Docker Installation on Ubuntu
Step 1:Update and install the system dependencies before install docker

sudo apt-get update

sudo apt-get install ca-certificates curl gnupg -y

Step 2: Add GPG (GNU Privacy Guard) key is used to ensure the authenticity of the packages that are being downloaded from Docker

sudo install -m 0755 -d /etc/apt/keyrings

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
sudo chmod a+r /etc/apt/keyrings/docker.gpg

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

Step 3: Now we start install Docker & Docker plugins

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

• InstallDocker-Compose Plugins

curl -L "https://github.com/docker/compose/releases/download/v2.21.0/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

ls -lsh /usr/local/bin/docker-compose

chmod +x /usr/local/bin/docker-compose

ln -s /usr/local/bin/docker-compose /usr/bin/docker-compose

• Verify the Docker & Docker compose version

 docker version && docker-compose version

• Restart,enable the Docker service

sudo systemctl restart docker 
sudo systemctl enable docker 

• Check the status of Docker service

sudo systemctl status docker

Step 4: Create a Docker Group and add user to the group

sudo groupadd docker

sudo usermod -aG docker $USER

newgrp docker

Finally Docker Engine Installation was successfully completed