> For the complete documentation index, see [llms.txt](https://42-guide.gitbook.io/42-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://42-guide.gitbook.io/42-guide/docker/installation.md).

# Installation

## Linux

## How to Install Docker on Linux (Step by Step)

Here’s a simple guide to install Docker on your Linux system from scratch.

***

#### **Step 1: Update Your System**

Always start by updating your package list to ensure you have the latest software versions.

Open a terminal and run:

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

#### **Step 2: Install Required Packages**

Install a few prerequisites needed for Docker installation.

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

***

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

Download and add Docker’s GPG key to verify the software package.

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

***

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

Add Docker’s repository to your system so you can install the latest version.

```bash
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 5: Install Docker**

1. Update your package list again to include Docker’s repository.

   ```bash
   sudo apt update
   ```
2. Install Docker.

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

***

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

To check if Docker is installed correctly, run:

```bash
docker --version
```

It should display the installed version of Docker.

***

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

By default, Docker needs `sudo` to run. If you want to use Docker without `sudo`:

1. Add your user to the `docker` group:

   ```bash
   sudo usermod -aG docker $USER
   ```
2. Log out and log back in to apply the changes.

***

#### **Step 8: Test Docker**

Run a test container to confirm everything works:

```bash
sudo docker run hello-world
```

You should see a message saying Docker is installed and working!

***

#### **Notes:**

* These steps are for Ubuntu-based Linux distributions. For other distributions (e.g., CentOS, Fedora), steps may vary slightly.
* Always refer to the official Docker documentation for the latest instructions.

source -> i found nice video for Learning Docker -> 


---

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