> ## Documentation Index
> Fetch the complete documentation index at: https://programming-for-career.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Install Docker on Ubuntu

> Learn how to install Docker on Ubuntu in a few simple steps.

To install **Docker** on **Ubuntu**, follow these steps:

## **Step 1: Uninstall Old Versions (If Any)**

If you have an older version of Docker installed, remove it first:

```sh theme={null}
sudo apt remove docker docker-engine docker.io containerd runc
```

## **Step 2: Update Package List**

Update the package index and install dependencies:

```sh theme={null}
sudo apt update
sudo apt install -y ca-certificates curl gnupg
```

## **Step 3: Add Docker’s Official GPG Key**

```sh theme={null}
sudo install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo tee /etc/apt/keyrings/docker.gpg > /dev/null
sudo chmod a+r /etc/apt/keyrings/docker.gpg
```

## **Step 4: Add Docker Repository**

```sh theme={null}
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
```

Then, update the package list again:

```sh theme={null}
sudo apt update
```

## **Step 5: Install Docker Engine, CLI, and Containerd**

```sh theme={null}
sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
```

## **Step 6: Verify Docker Installation**

Check if Docker is installed correctly:

```sh theme={null}
docker --version
```

Start the Docker service:

```sh theme={null}
sudo systemctl start docker
sudo systemctl enable docker
```

Test Docker with a Hello World container:

```sh theme={null}
sudo docker run hello-world
```

## **Step 7: Run Docker Without `sudo` (Optional)**

By default, Docker requires root privileges. To allow your user to run Docker without `sudo`:

```sh theme={null}
sudo usermod -aG docker $USER
```

Then, **log out and log back in** or run:

```sh theme={null}
newgrp docker
```

Now, try running:

```sh theme={null}
docker ps
```

## **Step 8: Enable Docker to Start on Boot**

```sh theme={null}
sudo systemctl enable docker
```

### **Bonus: Install Docker Compose**

Docker Compose allows you to run multi-container applications. Install it using:

```sh theme={null}
sudo apt install -y docker-compose-plugin
```

Verify installation:

```sh theme={null}
docker compose version
```