Analyzing image layers with dive in Docker - Mini Project: Build & Apply

Analyzing Image Layers with Dive

📖 Scenario: You are working on a Docker project and want to understand how your Docker image is built layer by layer. This helps you see which files and commands add size and how to optimize your image.

🎯 Goal: Learn how to use the dive tool to analyze Docker image layers and understand their contents.

📋 What You'll Learn

Have Docker installed and running on your machine

Have the dive tool installed (https://github.com/wagoodman/dive)

Have a Docker image built locally to analyze

💡 Why This Matters

🌍 Real World

Developers and DevOps engineers often need to optimize Docker images to reduce size and improve deployment speed. Understanding image layers helps identify unnecessary files or commands.

💼 Career

Knowing how to analyze Docker images with tools like dive is valuable for roles involving containerization, cloud deployments, and continuous integration pipelines.

1

Create a simple Docker image

Create a Dockerfile with the exact content:
FROM alpine:3.18
RUN apk add --no-cache curl
CMD ["curl", "--version"]

Docker

# Create a Dockerfile with the specified content
# Your code here

Need a hint?

Use a text editor to create a file named Dockerfile with the exact lines given.

2

Build the Docker image

Build the Docker image with the tag mycurlimage using the command:
docker build -t mycurlimage .

Docker

FROM alpine:3.18
RUN apk add --no-cache curl
CMD ["curl", "--version"]
# Run the docker build command below
# Your code here

Need a hint?

Run the exact command in your terminal to build the image.

3

Analyze the image layers with dive

Run the command dive mycurlimage to open the dive interface and analyze the image layers.

Docker

FROM alpine:3.18
RUN apk add --no-cache curl
CMD ["curl", "--version"]
# Command to build image:
docker build -t mycurlimage .
# Run dive to analyze the image below
# Your code here

Need a hint?

Make sure dive is installed and run the command exactly as shown.

4

Print the image size summary

Run the command docker images mycurlimage --format "{{.Repository}}: {{.Size}}" to display the image size summary.

Docker

FROM alpine:3.18
RUN apk add --no-cache curl
CMD ["curl", "--version"]
# Command to build image:
docker build -t mycurlimage .
# Run dive to analyze image layers:
dive mycurlimage
# Run docker images command below to print image size
# Your code here

Need a hint?

This command shows the image name and its size in a simple format.