2.6

2.6 Lab - Building Containers

Introduction

In this hands-on lab, you'll gain practical experience with Docker by building a simple container using the BusyBox image. BusyBox combines tiny versions of many common UNIX utilities into a single small executable, making it an excellent choice for learning about container creation and operation with minimal complexity.

Objectives

Learn how to create a Docker container using the BusyBox image.
Explore basic Docker commands for container management.
Understand how to interact with a container using the Docker CLI.

Lab Steps

Step 1: Setting Up Your Environment

Ensure Docker is installed on your Linux system by running docker --version in your terminal.
Confirm Nano is available for editing: nano --version. If not, install it using your distribution's package manager.

Step 2: Pulling the BusyBox Image

Pull the BusyBox image from Docker Hub:
```
docker pull busybox
```
Verify the image is pulled successfully by listing all Docker images:
```
docker images
```

Step 3: Running a Container with BusyBox

Start a new container using the BusyBox image in interactive mode:
```
docker run -it --name mybusybox busybox
```
You are now in a shell session inside the container. Feel free to explore BusyBox commands, such as ls, echo, and whoami.

Step 4: Creating a Simple Text File inside the Container

While still in the container's shell session, use the built-in vi editor to create a text file:
```
vi hello.txt
```
Enter some text, such as "Hello from BusyBox!", then save and exit vi (ESC then :wq).

Step 5: Exiting the Container

Exit the container shell without stopping the container by typing exit.
The container will stop because BusyBox exits when the interactive shell is closed.

Step 6: Inspecting the Container

Inspect the stopped container to see its details:
```
docker inspect mybusybox
```

Step 7: Starting the Container Again

Start the container again in interactive mode to check the persistence of the hello.txt file:
```
docker start -ai mybusybox
```
Once inside, use cat hello.txt to display the content of the file.

Summary

Through this lab, you've successfully created and interacted with a Docker container using the BusyBox image. Starting with pulling the BusyBox image from Docker Hub, you ran a container in interactive mode, explored some UNIX commands, created a text file inside the container, and observed the persistence of data across container restarts. This lab provided a fundamental understanding of building and managing Docker containers, highlighting the ease and efficiency of containerization with Docker.