While working on a project for my degree at 42 Quebec, I discovered DevOps and thus a new passion. This little tutorial is the first of a series talking about Docker, Kubernetes, Ansible, Teraform and many other tools needed to become a great DevOps engineer. So let's start With Docker, but what is Docker and why is learning it such a big deal?
Docker and Its Utility
Docker is a containerization platform that allows you to build, ship, and run applications in a consistent and portable way. It is used to package an application along with its dependencies into a container, which can then be deployed on any system that has Docker installed. Docker containers are lightweight, fast, and isolated, making them an ideal choice for deploying applications in production.
How Docker Works
Docker works by using a layered file system and image-based containerization. Each Docker container is built from an image that includes all the dependencies needed to run the application. Images are built using a Dockerfile, which is a text file that contains the instructions for building the image. The Dockerfile specifies the base image, the commands to install the dependencies, and any additional configuration needed to run the application.
Once the image is built, it can be used to create Docker containers. Each container runs in its own isolated environment and has its own file system, network interfaces, and processes. Containers can communicate with each other through a shared network, making it easy to deploy and manage multiple applications on a single system.
Benefits of Docker
There are several benefits to using Docker for application deployment:
Docker containers are portable, meaning that they can be run on any system that has Docker installed. This makes it easy to move applications between development, staging, and production environments without worrying about dependencies or configuration issues.
Docker containers are consistent, meaning that they provide the same environment for running an application regardless of the host system. This eliminates the "works on my machine" problem that can arise when developing and deploying applications on different systems.
Docker containers are lightweight, meaning that they can be quickly spun up or down to meet changes in demand. This makes it easy to scale applications horizontally by adding or removing containers as needed.
Docker containers are isolated, meaning that they provide a secure environment for running applications without affecting the host system. This makes it easy to run multiple applications on a single system without worrying about conflicts or resource contention.
Getting Started with Docker
To get started with Docker, you'll need to install Docker on your system. Docker provides installers for Windows, macOS, and Linux. Once Docker is installed, you can start building Docker images using a Dockerfile and creating Docker containers from those images.
Here's an example Dockerfile for a simple Node.js application:
FROM node:14-alpine WORKDIR /app COPY package*.json ./ RUN npm install COPY . . EXPOSE 3000 CMD ["npm", "start"]
This Dockerfile specifies that we want to use the
node:14-alpine base image, set the working directory to
/app, copy the
package-lock.json files to the container, install the dependencies using
npm, copy the application files to the container, expose port
3000, and start the application using
To build the Docker image, run the following command:
docker build -t my-node-app .
This command tells Docker to build a Docker image with the tag
my-node-app using the Dockerfile in the current directory (
To create a Docker container from the image, run the following command:
docker run -p 3000:3000 my-node-app
This command tells Docker to create a Docker container from the
my-node-app image and map port
3000 on the host system to port
3000 in the container.
Docker is a powerful tool for building, shipping, and running applications in a consistent and portable way. Its benefits include portability, consistency, scalability, and isolation, making it an ideal choice for deploying applications in production. With Docker, you can easily package your application along with its dependencies into a container and deploy it on any system that has Docker installed. Whether you're a developer, system administrator, or IT professional, Docker can help simplify your workflow and streamline your application deployment process. Give Docker a try and see how it can help you build and deploy applications more efficiently.
Top comments (2)
Thanks for sharing
My pleaser brother 🙏