🐳 Installing Docker on Ubuntu: A Complete Guide for Beginners 🐳

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🔍 What is Docker?

It’s a container-based virtualization platform that provides a “build once, run anywhere” environment.
✅ Runs faster and is lighter than traditional virtualization (VMs) Simplifies application deployment and management Ensures consistency across dev/test/production environments

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⚙️ Preparation before installation

1. Check Ubuntu version (20.04 LTS or higher recommended)

   
   lsb_release -a
   ```bash lsb_release -a
   ![Example output](https://via.placeholder.com/400x50?text=Distributor+ID%3A+Ubuntu+%0ARelease%3A+22.04)

2. **Update the repository

   
   sudo apt update && sudo apt upgrade -y
   ```bash

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🚀 Step-by-step guide to installing Docker

1️⃣ Uninstall the previous Docker (optional)

sudo apt remove docker docker-engine docker.io containerd runc

2️⃣ Install prerequisite packages

sudo apt install -y ca-certificates curl gnupg lsb-release

3️⃣ Add the Docker official GPG key 🔑

sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

4️⃣ Set up a repository 📦

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

5️⃣ Install the Docker engine

sudo apt update
sudo apt install -y docker-ce docker-ce-cli containerd.io docker-compose-plugin

6️⃣ Verify the installation 🎉 .

sudo docker run hello-world

✅ Print on success

Hello from Docker!  
This message shows your installation appears to be working correctly.

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⚡ Set user permissions (prevent sudo every time)

sudo usermod -aG docker $USER # add current user docker group
newgrp docker # Apply group settings immediately

✏️ Apply without reboot: `newgrp docker or rerun terminal

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🛠️ Additional useful settings

🔄 Enable Docker autostart

sudo systemctl enable docker.service
sudo systemctl enable containerd.service
```bash

#### 🔄 Control the Docker service
```bash
sudo systemctl start docker # Start
sudo systemctl stop docker # Stop
sudo systemctl restart docker # restart
```bash

#### ℹ️ Check the version
```bash
docker --version # Docker version
docker compose version # Compose plugin version

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🧪 Test the installation: Run the Nginx container

docker run -d -p 8080:80 --name my-nginx nginx

1. access http://localhost:8080 in your browser
2. see “Welcome to nginx!” 3. stop and delete the container
3. stop and delete the container:

   docker stop my-nginx && docker rm my-nginx

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❌ Troubleshooting tips.

• “Permission denied”** error:

  sudo chmod 666 /var/run/docker.sock # Temporary workaround (security alert!)

  → Permanent workaround: re-login user or run newgrp docker

• GPG key error: re-run sudo apt update after adding repository

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✅ Closing checklist.

• [ ] Successfully run hello-world container
• [ ] User permission groups added successfully
• [ ] Nginx test container working properly
• [ ] Docker service auto-start enabled

> 📢 **Feel the power of Docker! > Set up development environment in 5 minutes ➜ Deploy production in 1 second 😎 > bash > # Example: Running a MySQL container. > docker run -d -p 3306:3306 -e MYSQL_ROOT_PASSWORD=my-secret-pw --name my-db mysql:8.0 >

Your container journey has begun 🚢. Build an efficient development environment with Ubuntu + Docker combination!