My First Docker Container: Installation and Essential Commands

In the previous article, we learned what Docker is and why it became one of the most important tools in modern software development and DevOps.

Now it’s time to do something practical.

In this article, we will install Docker and run our first Docker container. By the end, you will understand the most important Docker commands that every beginner should know.

Installing Docker

Docker is available for Windows, macOS, and Linux.

Windows

Download Docker Desktop from the official Docker website and complete the installation.

After installation, open Docker Desktop and wait until Docker starts successfully.

Linux (Ubuntu)

Update the package list:

sudo apt update

Install Docker:

sudo apt install docker.io -y

Start the Docker service:

sudo systemctl start docker

Enable Docker to start automatically after reboot:

sudo systemctl enable docker

Check whether Docker is installed correctly:

docker --version

You should see an output similar to:

Docker version 28.x.x

Running your first Docker command

The easiest way to test Docker is:

docker run hello-world

This command downloads a small image called hello-world and runs it.

You should see a welcome message confirming that Docker is working correctly.

Congratulations! You have just run your first Docker container.

Understanding what happened

The command:

docker run hello-world

actually performs several steps automatically.

1. Docker looks for the hello-world image locally.
2. If it is not available, Docker downloads it from Docker Hub.
3. Docker creates a container from that image.
4. Docker starts the container.
5. The container prints a message and exits.

This single command demonstrates the basic Docker workflow.

Docker images

A Docker image is a template used to create containers.

To see downloaded images:

docker images

Example output:

REPOSITORY    TAG       IMAGE ID       CREATED       SIZE
hello-world   latest    abc123xyz      2 weeks ago   13KB

The most important columns are:

• Repository – image name
• Tag – version
• Image ID – unique identifier
• Size – image size

Downloading an image manually

Instead of running a container immediately, you can download an image first.

For example:

docker pull nginx

This downloads the Nginx web server image.

Verify:

docker images

You should now see the Nginx image.

Running a container

To create and start a container:

docker run nginx

Docker starts the Nginx web server.

However, the terminal becomes occupied because the container is running in the foreground.

Stop it with:

Ctrl + C

Running a container in the background

Use the -d option (detached mode):

docker run -d nginx

Docker returns a long container ID.

The container continues running in the background.

Viewing running containers

To see active containers:

docker ps

Example:

CONTAINER ID   IMAGE   STATUS
a12b34c56d78   nginx   Up 2 minutes

Useful columns:

• Container ID
• Image
• Status

Viewing all containers

Even stopped containers are stored on your system.

To see them:

docker ps -a

This shows:

• running containers
• stopped containers
• exited containers

Stopping a container

First, find the container ID:

docker ps

Then stop it:

docker stop container_id

Example:

docker stop a12b34c56d78

Docker stops the running container.

Starting a stopped container

To start it again:

docker start container_id

Example:

docker start a12b34c56d78

The container resumes execution.

Removing a container

A stopped container can be deleted.

docker rm container_id

Example:

docker rm a12b34c56d78

If the container is running, stop it first.

Removing an image

To delete an image:

docker rmi nginx

If a container is using the image, Docker will prevent removal.

Delete the container first, then remove the image.

Running Ubuntu interactively

One of the most useful beginner commands is:

docker run -it ubuntu

The options mean:

• -i = interactive
• -t = terminal

You enter a shell inside the Ubuntu container.

Try:

ls
pwd
echo Hello Docker

To exit:

exit

The container stops after exiting the shell.

Giving a container a name

Instead of using random IDs:

docker run -d --name mynginx nginx

Now the container has the name mynginx.

Stop it:

docker stop mynginx

Start it:

docker start mynginx

Remove it:

docker rm mynginx

Names are much easier to remember than container IDs.

Checking container logs

To view application logs:

docker logs mynginx

This is extremely useful for debugging.

For continuous log monitoring:

docker logs -f mynginx

Press Ctrl + C to stop following the logs.

Executing commands inside a running container

Suppose Nginx is running.

Open a shell inside it:

docker exec -it mynginx bash

Some images use sh instead of bash:

docker exec -it mynginx sh

Now you are working inside the running container.

Exit with:

exit

The five commands you should memorize

If you are completely new to Docker, focus on these commands first.

Download an image:

docker pull nginx

Run a container:

docker run -d --name mynginx nginx

View containers:

docker ps

Stop a container:

docker stop mynginx

Remove a container:

docker rm mynginx

These commands cover most beginner Docker tasks.

A quick practice exercise

Try this sequence yourself:

docker pull nginx
docker run -d --name web nginx
docker ps
docker logs web
docker stop web
docker start web
docker exec -it web bash
exit
docker stop web
docker rm web

Running these commands once is far better than reading them ten times.

What’s next?

In the next article, we will learn Docker architecture in detail. We will understand images, containers, Docker Hub, and the Docker engine, and see what happens behind the scenes when you run a Docker command.

The more you practice these basic commands, the easier Docker will become.

Happy learning!