Install Docker with a Bash Script – One Command Setup 🐳

🐳 Why Use a Bash Script to Install Docker?

Installing Docker manually works fine for a single server, but when you need to set up multiple machines or want a repeatable, error-free process, a bash script is the way to go.

Benefits of scripted installation:

⚡ Speed: Install Docker in one command instead of running multiple steps
🔄 Consistency: Every server gets the exact same setup
🚀 Automation: Perfect for provisioning new servers in CI/CD pipelines
📋 Documentation: The script itself serves as documentation of your setup process

✅ Prerequisites

Before running the script, make sure you have:

🖥️ Ubuntu 20.04, 22.04, or 24.04 server
🔐 Sudo privileges to execute administrative commands
🌐 Internet connection to download packages
⏱️ Time: The script takes approximately 2-5 minutes to complete

The Installation Script

Below is a complete bash script that handles the entire Docker installation process, including cleanup of old versions, repository setup, installation, and user permission configuration.

Create the script file:

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nano install-docker.sh

Paste the following content:

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#!/bin/bash

set -e

GREEN='\033[0;32m'
RED='\033[0;31m'
YELLOW='\033[1;33m'
NC='\033[0m'

echo -e "${GREEN}========================================${NC}"
echo -e "${GREEN}  Docker Installation Script for Ubuntu ${NC}"
echo -e "${GREEN}========================================${NC}"

# Check if running as root or with sudo
if [ "$EUID" -ne 0 ]; then
    echo -e "${RED}[ERROR] Please run this script with sudo or as root.${NC}"
    exit 1
fi

# Detect Ubuntu version
UBUNTU_VERSION=$(lsb_release -cs)
echo -e "${YELLOW}[INFO] Detected Ubuntu version: ${UBUNTU_VERSION}${NC}"

# Step 1: Remove old Docker versions
echo -e "${YELLOW}[1/6] Removing old Docker versions (if any)...${NC}"
apt-get remove -y docker docker-engine docker.io containerd runc 2>/dev/null || true

# Step 2: Update system and install dependencies
echo -e "${YELLOW}[2/6] Updating system and installing dependencies...${NC}"
apt-get update -y
apt-get install -y \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg \
    lsb-release \
    software-properties-common

# Step 3: Add Docker's official GPG key
echo -e "${YELLOW}[3/6] Adding Docker GPG key...${NC}"
install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
chmod a+r /etc/apt/keyrings/docker.gpg

# Step 4: Add Docker repository
echo -e "${YELLOW}[4/6] Adding Docker repository...${NC}"
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
  ${UBUNTU_VERSION} stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null

# Step 5: Install Docker Engine
echo -e "${YELLOW}[5/6] Installing Docker Engine...${NC}"
apt-get update -y
apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

# Step 6: Enable and start Docker
echo -e "${YELLOW}[6/6] Enabling and starting Docker service...${NC}"
systemctl enable docker
systemctl start docker

# Add current user to docker group (if run via sudo)
if [ -n "$SUDO_USER" ]; then
    usermod -aG docker "$SUDO_USER"
    echo -e "${GREEN}[INFO] User '${SUDO_USER}' added to the docker group.${NC}"
    echo -e "${YELLOW}[NOTE] Log out and back in for group changes to take effect.${NC}"
fi

# Verify installation
echo ""
echo -e "${GREEN}========================================${NC}"
echo -e "${GREEN}  Installation Complete! 🎉            ${NC}"
echo -e "${GREEN}========================================${NC}"
echo ""
docker --version
docker compose version
echo ""
echo -e "${GREEN}[SUCCESS] Docker is installed and running.${NC}"
echo -e "${YELLOW}[TIP] Run 'docker run hello-world' to verify.${NC}"

How to Use the Script

Run Directly

Make the script executable and run it:

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chmod +x install-docker.sh
sudo ./install-docker.sh

Run Without Downloading

You can also run the script directly from a URL using curl (useful for remote server provisioning):

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curl -fsSL https://your-server.com/install-docker.sh | sudo bash

⚠️ Security Note: Always review scripts before piping them to bash. Only use this method with scripts you trust or host yourself.

What the Script Does

Here’s a breakdown of each step:

Step	Action	Purpose
1	Remove old Docker versions	Prevents conflicts with previous installations
2	Update system & install dependencies	Ensures required packages are available
3	Add Docker GPG key	Authenticates packages from Docker’s repository
4	Add Docker repository	Configures APT to pull packages from Docker
5	Install Docker Engine	Installs Docker CE, CLI, containerd, Buildx, and Compose
6	Enable & start Docker	Ensures Docker runs now and on every boot

Verifying the Installation

After the script completes, verify everything is working:

Check Docker version:

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docker --version

Check Docker Compose version:

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docker compose version

Run the test container:

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docker run hello-world

If you see the “Hello from Docker!” message, the installation was successful! 🎉

Check Docker service status:

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sudo systemctl status docker

You should see active (running) in the output.

Customizing the Script

You can extend the script to fit your needs:

Add Docker Compose Standalone

If you need the standalone docker-compose command (v1 syntax):

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# Add this to the end of the script
COMPOSE_VERSION=$(curl -s https://api.github.com/repos/docker/compose/releases/latest | grep tag_name | cut -d '"' -f 4)
curl -L "https://github.com/docker/compose/releases/download/${COMPOSE_VERSION}/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
chmod +x /usr/local/bin/docker-compose

Add Automatic Cleanup

Add a cleanup step to remove unnecessary packages after installation:

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# Add this before the final success message
apt-get autoremove -y
apt-get clean

🔧 Troubleshooting

Script fails with “Permission denied”

Cause: The script was not run with sudo.

Solution:

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sudo ./install-docker.sh

Script fails at GPG key step

Cause: Network issues or DNS resolution problems.

Solution:

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# Check internet connectivity
ping -c 3 download.docker.com

# If DNS fails, try using Google's DNS
echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf

Docker commands require sudo after script

Cause: Group changes haven’t taken effect yet.

Solution:

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# Log out and log back in, or run:
newgrp docker

# Verify group membership
groups

🎯 Conclusion

Using a bash script to install Docker saves time and eliminates manual errors. Whether you’re setting up a single development machine or provisioning a fleet of production servers, this script provides a reliable and repeatable process. 🚀

Key takeaways:

📜 One command to install Docker completely
🔄 Idempotent — safe to run multiple times
🛠️ Customizable — extend the script for your specific needs
🚀 Production-ready — includes Docker Compose plugin and Buildx

📖 References:

Happy automating! 🚀😊