2.2

2.2 Lab - Introduction to Docker

Introduction

Welcome to the "Introduction to Docker" hands-on lab, where you will get your first taste of working with Docker through the command line interface (CLI). This lab is designed to provide you with practical experience in using Docker, focusing on basic commands and operations. By the end of this lab, you will have learned how to manage Docker images and containers directly from your terminal using a Linux environment and the Nano editor.

Objectives

Learn how to pull Docker images from Docker Hub.
Understand how to run Docker containers.
Explore basic Docker container management commands.
Familiarize yourself with viewing logs and accessing running containers.

Lab Steps

Step 1: Setting Up Your Environment

Ensure Docker is installed on your Linux system. If Docker is not installed, please refer to the official Docker documentation for installation instructions.
Verify Docker installation by running docker --version in your terminal.

Step 2: Pulling a Docker Image

Pull the official "hello-world" Docker image from Docker Hub:
```
docker pull hello-world
```
List all Docker images on your system to confirm the image was pulled successfully:
```
docker images
```

Step 3: Running a Docker Container

Run the "hello-world" container:
```
docker run hello-world
```
This command will create a new container from the "hello-world" image and execute it. You should see a message indicating that your Docker installation appears to be working correctly.

Step 4: Managing Docker Containers

List all running containers:
```
docker ps
```
Since the "hello-world" container exits after displaying its message, you may need to list all containers, including stopped ones, to see it:
```
docker ps -a
```
Stop a running container (replace CONTAINER_ID with your container's actual ID):
```
docker stop CONTAINER_ID
```
Remove a stopped container:
```
docker rm CONTAINER_ID
```

Step 5: Accessing and Managing Container Logs

Run a new container in the background using the Nginx image:
```
docker run -d --name my-nginx nginx
```
Access the logs of the running container:
```
docker logs my-nginx
```

Step 6: Executing Commands Inside a Running Container

Access the shell of the "my-nginx" container:
```
docker exec -it my-nginx /bin/bash
```
Feel free to explore the container's filesystem. Exit the shell when done by typing exit.

Step 7: Cleanup

Get the process id of the running container

docker ps

You should see something like the following:

CONTAINER ID   IMAGE     COMMAND                  CREATED         STATUS         PORTS     NAMES
55c609cf59ad   nginx     "/docker-entrypoint.…"   3 minutes ago   Up 3 minutes   80/tcp    my-nginx

Now stop the running container use the id listed in the previous command. Note your id will bw different.

rm -f 55c609cf59ad

Run the 'docker ps' command again to verify

docker ps

There should be no containers running now.

CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

Summary

In this introductory lab to Docker, you've taken your first steps into the world of Docker containers. You've learned how to pull images from Docker Hub, run containers, and manage them using basic Docker CLI commands. Additionally, you've explored accessing container logs and executing commands inside running containers. These foundational skills are crucial as you continue to explore more complex Docker functionalities in future labs. Docker opens up a world of possibilities for developing, shipping, and running applications, and you're now equipped with the knowledge to begin experimenting on your own.