Installing Docker CLI on Ubuntu (Step-by-Step Guide)

If you're working with containers, Docker is one of the most essential tools you’ll need. In this guide, I’ll walk you through installing the Docker CLI (along with the Docker Engine) on an Ubuntu system in a simple and practical way.

Prerequisites

Before you start, make sure:

• You’re using an Ubuntu system (18.04 or later recommended)
• You have a user account with sudo privileges
• Your system is connected to the internet

Steps

Step 1: Update Package Index

Start by updating your system’s package list:

sudo apt update

Install required dependencies:

sudo apt install -y apt-transport-https ca-certificates curl software-properties-common

Step 2: Add Docker’s Official GPG Key

This ensures packages are verified and trusted:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

Step 3: Add Docker Repository

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

Step 4: Install Docker Engine & CLI

Update package list again:

sudo apt update

Now install Docker:

sudo apt install -y docker-ce docker-ce-cli containerd.io

Step 5: Start and Enable Docker

Start Docker service:

sudo systemctl start docker

Enable Docker to start on boot:

sudo systemctl enable docker

Step 6: Run Docker Without sudo (Optional but Recommended)

By default, Docker requires sudo. To avoid that, add your user to the Docker group:

sudo usermod -aG docker $USER

Apply the changes immediately:

newgrp docker

Step 7: Verify Installation

Check Docker system info:

docker info

List running containers:

docker ps

Quick Note

• docker-ce → Docker Engine
• docker-ce-cli → Docker CLI
• containerd.io → Container runtime

Conclusion

You now have Docker CLI installed and ready to use on Ubuntu. This setup is ideal for development, testing, and learning containerization.

From here, you can start running containers, pulling images, or even building your own.