Installing Docker on Ubuntu Machine

What is Docker?

Docker is an open-source platform designed to make it easier to create, deploy, and run applications within lightweight, portable containers. Containers are isolated environments that package an application along with all its dependencies, such as libraries and binaries, ensuring the application runs consistently regardless of the host environment.

Key Concepts

• Containers: Docker containers are similar to virtual machines (VMs) but are much more lightweight. They share the host system’s OS kernel, which makes them faster to start, and they consume fewer resources compared to VMs.
• Images: Docker images are templates for creating containers. They contain everything an application needs to run, including code, runtime, libraries, environment variables, and configuration files.
• Dockerfile: A script with a set of instructions on how to build a Docker image. It defines what’s included in the image, such as the base OS, required software, and configurations.
• Docker Hub: A cloud-based registry where Docker users can share images. It includes both official images (maintained by Docker) and community-contributed images.

Benefits of Docker

1. Consistency Across Environments: Docker ensures that applications behave the same in development, testing, and production by isolating dependencies and configuration.
2. Resource Efficiency: Containers are lightweight, making them more efficient in terms of CPU, memory, and storage usage.
3. Scalability: Docker containers are well-suited for microservices architectures, where applications are broken down into small, manageable services that can be scaled independently.
4. Simplified CI/CD: Docker streamlines the CI/CD pipeline by allowing developers to create portable application components that work across different environments, speeding up testing and deployment.

To Installing Docker on Ubuntu Machine, you can follow these steps. These steps work for Ubuntu 18.04, 20.04, 22.04, and later versions.

# Update system
sudo apt update

# Install docker
sudo apt install -y docker.io

# Setting group docker
sudo usermod -aG docker $USER &&
sudo usermod -aG docker linux &&
newgrp docker

# activate and verify service
sudo systemctl enable docker
sudo systemctl start docker
sudo systemctl status docker

# seeing docker version
docker version

Use Cases

• Application Development and Testing: Ensures that code runs the same on developers’ machines and in production.
• Microservices: Helps in implementing a microservices architecture by containerizing each service independently.
• Continuous Integration and Deployment (CI/CD): Simplifies building, testing, and deploying applications.
• Cloud Migration: Makes it easier to move applications across different cloud environments.

Docker has become a standard in DevOps and cloud-native development, helping teams to manage software more effectively and reliably across various infrastructure setups.