Why registries store and distribute images in Docker - See It in Action

Understanding Why Registries Store and Distribute Docker Images

📖 Scenario: You are working as a DevOps engineer. Your team uses Docker containers to run applications. You want to understand why Docker registries are important for storing and sharing container images.

🎯 Goal: Learn how to create a simple Docker image list, configure a registry URL, and simulate pushing images to a registry. Finally, display the list of images ready to be pushed.

📋 What You'll Learn

Create a list of Docker image names with exact values

Add a variable for the Docker registry URL

Use a loop to prepare full image names with the registry prefix

Print the final list of full image names

💡 Why This Matters

🌍 Real World

Docker registries are like libraries for container images. They store images so developers and systems can share and reuse them easily.

💼 Career

Understanding registries is key for DevOps roles because managing container images efficiently is part of deploying and scaling applications.

1

Create a list of Docker image names

Create a list called images with these exact Docker image names: "nginx:latest", "redis:6.2", and "python:3.12-slim".

Docker

# Create the list called images with the exact names
# Your code here

Need a hint?

Use square brackets to create a list and include the exact strings inside quotes.

2

Add a Docker registry URL variable

Create a variable called registry_url and set it to the exact string "docker.io/myteam".

Docker

images = ["nginx:latest", "redis:6.2", "python:3.12-slim"]
# Create the variable registry_url with the exact value
# Your code here

Need a hint?

Use an equals sign to assign the string to the variable.

3

Create full image names with registry prefix

Use a for loop with the variable image to iterate over images. Inside the loop, create a new list called full_images that contains each image name prefixed with registry_url and a slash /. Use an f-string to combine them.

Docker

images = ["nginx:latest", "redis:6.2", "python:3.12-slim"]
registry_url = "docker.io/myteam"
# Use a for loop to create full_images list with registry prefix
# Your code here

Need a hint?

Start with an empty list, then add each full image name inside the loop.

4

Print the list of full image names

Write a print statement to display the full_images list.

Docker

images = ["nginx:latest", "redis:6.2", "python:3.12-slim"]
registry_url = "docker.io/myteam"
full_images = []
for image in images:
    full_images.append(f"{registry_url}/{image}")
# Print the full_images list
# Your code here

Need a hint?

Use print(full_images) to show the list on the screen.