Install Docker on Ubuntu

Docker is a platform for developing, shipping, and running applications in containers. It allows you to package applications with their dependencies.

Step 1: Update package lists

First, update your package lists:

bash

sudo apt update

Step 2: Install Docker

Install Docker using the apt package manager:

bash

sudo apt install docker.io -y

This installs the Docker Engine from Ubuntu's official repositories.

Step 3: Add user to docker group

Add your user to the docker group to run Docker commands without sudo:

bash

sudo usermod -aG docker $USER

Important: You'll need to log out and log back in for this change to take effect.

Step 4: Verify Docker

Check that Docker was installed successfully:

bash

docker --version

You should see output similar to Docker version 24.0.5.

Step 5: Test Docker

Run a test container to verify everything is working:

bash

docker run hello-world

This downloads and runs a simple test image.

Alternative: Install Docker from official repository

For the latest version, you can install from Docker's official repository:

bash

# Remove old versions
sudo apt remove docker docker-engine docker.io containerd runc

# Install prerequisites
sudo apt install apt-transport-https ca-certificates curl gnupg lsb-release

# 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

# Add repository
echo "deb [arch=amd64 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
sudo apt update
sudo apt install docker-ce docker-ce-cli containerd.io

Next Steps

Now that Docker is installed, you can:

Pull and run Docker images
Build your own Docker images
Use Docker Compose for multi-container applications
Deploy applications in containers