Introduction

2 min readFeb 15, 2024

Docker is a powerful tool for containerization, allowing developers to encapsulate their applications and dependencies into portable containers. In this blog, we’ll cover the basics of Docker, including creating Docker images, launching containers, and using Docker Compose.

Chapter 1: Docker Image Basics

1.1 Pulling and Running an Image

When an image is not available locally, Docker automatically downloads it before launching the container. Let’s pull and run an Nginx web server image:

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

This command pulls the Nginx image and runs a container named ‘my-nginx,’ mapping port 8080 on the host to port 80 in the container.

1.2 Accessing Containerized Websites

You can use curl to access a website running in a container. For example:

curl http://localhost:8080

1.3 Attaching to Containers

To attach to a container with a bash shell, you can use the docker attach command. If the container doesn't have a bash shell, use docker exec:

docker exec -it my-nginx bash

Chapter 2: Tomcat Web Server

2.1 Dockerfile for Tomcat Server

Here’s a simple Dockerfile for a Tomcat web server:

FROM tomcat:latest
COPY ./webpages /usr/local/tomcat/webapps/ROOT

2.2 Building and Running Tomcat Container

Build the image using:

docker build -t my-tomcat .

Launch the container and expose port 8080:

docker run -d -p 8080:8080 — name my-tomcat-container my-tomcat

Access the web page using:

curl http://localhost:8080

Chapter 3: Docker Compose

3.1 Docker Compose File

Create a docker-compose.yml file for launching the Tomcat container:

version: ‘3’
services:
tomcat:
build: .
ports:
— “8080:8080”

3.2 Building and Launching with Docker Compose

Build and launch the container using Docker Compose:

docker-compose up -d

Chapter 4: Docker Compose with Image Building

4.1 Dockerfile Integration with Docker Compose

Use the build keyword in docker-compose.yml: