Executing commands with docker exec - Mini Project: Build & Apply

Executing commands with docker exec

📖 Scenario: You are managing a Docker container running a simple web server. You want to check the server's status and list files inside the container without stopping it.

🎯 Goal: Learn how to use docker exec to run commands inside a running container.

📋 What You'll Learn

Use docker exec to run commands inside a container

Identify the container by its name

Run simple commands like ls and cat inside the container

💡 Why This Matters

🌍 Real World

In real life, developers and system admins often need to check or fix things inside running containers without stopping them. Using <code>docker exec</code> lets you do that safely.

💼 Career

Knowing how to use <code>docker exec</code> is essential for troubleshooting, monitoring, and managing Docker containers in development and production environments.

1

Create and run a container named webserver

Run a Docker container named webserver using the nginx image in detached mode.

Docker

# Your code here

Need a hint?

Use docker run -d --name webserver nginx to start the container in the background.

2

Set a variable with the container name

Create a shell variable called container and set it to the string webserver.

Docker

docker run -d --name webserver nginx
# Your code here

Need a hint?

Use container=webserver to store the container name in a variable.

3

List files inside the container's /usr/share/nginx/html directory

Use docker exec with the variable container to run ls /usr/share/nginx/html inside the container.

Docker

docker run -d --name webserver nginx
container=webserver
# Your code here

Need a hint?

Use docker exec $container ls /usr/share/nginx/html to list files inside the container.

4

Display the content of the index.html file inside the container

Use docker exec with the variable container to run cat /usr/share/nginx/html/index.html inside the container and print the output.

Docker

docker run -d --name webserver nginx
container=webserver
docker exec $container ls /usr/share/nginx/html
# Your code here

Need a hint?

Use docker exec $container cat /usr/share/nginx/html/index.html to show the file content.