🐳 How to Install and Use Docker on Ubuntu 22.04

A step-by-step guide to installing Docker Community Edition (CE) on Ubuntu 22.04, based on the DigitalOcean Tutorial.

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📋 Table of Contents

• Prerequisites
• Installation Guide
  • Step 1: Update Packages
  • Step 2: Install Dependencies
  • Step 3: Add Docker Repository
  • Step 4: Install Docker Engine
• Post-Installation Configuration
• Verification

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🛠 Prerequisites

Before you begin, ensure you have:

• One Ubuntu 22.04 server.
• A user with sudo privileges.
• An active firewall (optional but recommended).

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🚀 Installation Guide

1. Update Packages

First, update your existing list of packages to ensure you are getting the latest versions.

sudo apt update

2. Install Dependencies

Install the prerequisite packages that allow apt to use packages over HTTPS.

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

3. Add Docker Repository

Add the GPG key for the official Docker repository to your system to ensure downloads are valid.

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

Add the Docker repository to your APT sources.

echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] [https://download.docker.com/linux/ubuntu](https://download.docker.com/linux/ubuntu) $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

4. Install Docker Engine

Update the package database again with the Docker packages from the newly added repo.

sudo apt update

Finally, install Docker.

sudo apt install docker-ce

⚙ Post-Installation Configuration

Run Docker Without Sudo (Optional) By default, the docker command can only be run by the root user or by a user in the docker group. To avoid typing sudo for every command, add your current user to the docker group.

Add your user to the docker group:

sudo usermod -aG docker ${USER}

Apply the new group membership (requires logging out or running the following):

su - ${USER}

Verify that your user is added to the group:

groups

Output should look like: sammy sudo docker

✅ Verification

Check that Docker is running correctly.

sudo systemctl status docker

To verify that you can pull images from Docker Hub, run the "Hello World" container:

docker run hello-world

If successful, you will see a message indicating that your installation appears to be working correctly.

📚 Resources

Official Docker Documentation DigitalOcean Docker Tutorial