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Getting Started with Docker: Your First Container

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    Name
    Hieu Cao
    Twitter

Introduction

Docker provides a straightforward way to build, run, and manage containerized applications. In this guide, we'll walk through the steps to create and run your first Docker container while covering some essential Docker commands.

Prerequisites

Before getting started, ensure the following:

  • Docker is installed on your system. Install Docker.
  • Basic familiarity with the command line.

Step 1: Pulling a Docker Image

Docker images are the blueprint for containers. You can pull official images from Docker Hub.

Example: Pulling the Nginx Image

docker pull nginx

This command downloads the latest nginx image from Docker Hub.

Step 2: Running a Docker Container

Once the image is downloaded, you can create and run a container from it.

Run the Nginx Container

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

Explanation:

  • -d: Runs the container in detached mode (background).
  • -p 8080:80: Maps port 8080 on the host to port 80 in the container.
  • --name my-nginx: Names the container my-nginx.
  • nginx: Specifies the image to use.

Now, open your browser and visit http://localhost:8080 to see the Nginx welcome page.

Step 3: Basic Docker Commands

Viewing Running Containers

docker ps

This command lists all currently running containers.

Viewing All Containers

docker ps -a

Lists all containers, including stopped ones.

Stopping a Container

docker stop my-nginx

Run the Nginx Container Existing

docker start my-nginx

Stops the my-nginx container.

Removing a Container

docker rm my-nginx

Deletes the my-nginx container. Ensure the container is stopped before removing it.

Viewing Downloaded Images

docker images

Lists all images available on your system.

Removing an Image

docker rmi nginx

Removes the nginx image.

Step 4: Running an Interactive Container

You can run a container interactively to execute commands inside it.

Example: Running an Ubuntu Container

docker run -it ubuntu

This command pulls the Ubuntu image (if not already downloaded) and starts a container with an interactive shell. You can now run commands inside the container.

Exit the container by typing:

exit

Step 5: Clean Up

To free up disk space, remove unused containers and images.

Remove Stopped Containers

docker container prune

Remove Unused Images

docker image prune

Conclusion

Creating your first Docker container is the initial step in mastering Docker's capabilities. By pulling images, running containers, and exploring basic commands, you're now equipped to experiment with Docker and integrate it into your development workflow.