BuildKit for improved builds in Docker - Mini Project: Build & Apply

BuildKit for improved builds

📖 Scenario: You are working on a Docker project and want to speed up your image builds. Docker BuildKit is a modern build engine that makes building images faster and more efficient.In this project, you will enable BuildKit and create a simple Dockerfile to see the benefits of improved builds.

🎯 Goal: Enable Docker BuildKit for your build process and create a Dockerfile that uses BuildKit features for faster and cleaner builds.

📋 What You'll Learn

Enable BuildKit by setting the environment variable DOCKER_BUILDKIT=1

Create a Dockerfile with a multi-stage build

Use BuildKit features like caching and secrets (basic usage)

Build the Docker image using BuildKit enabled

Display the build output to confirm BuildKit is active

💡 Why This Matters

🌍 Real World

BuildKit is used in real projects to speed up Docker image builds, reduce image size, and improve caching. It helps developers build images faster and with better control.

💼 Career

Knowing how to enable and use BuildKit is important for DevOps engineers and developers working with Docker, as it improves CI/CD pipelines and container build efficiency.

1

Enable BuildKit environment variable

Set the environment variable DOCKER_BUILDKIT=1 in your shell to enable BuildKit for Docker builds.

Docker

# Your code here

Need a hint?

Use export DOCKER_BUILDKIT=1 on Linux or macOS. On Windows PowerShell, use $env:DOCKER_BUILDKIT=1.

2

Create a multi-stage Dockerfile

Create a file named Dockerfile with a multi-stage build. Use FROM alpine AS builder for the first stage and FROM alpine for the final stage. In the builder stage, create a file /hello.txt with the text Hello BuildKit. Copy this file to the final stage.

Docker

export DOCKER_BUILDKIT=1
# Your code here

Need a hint?

Use multi-stage build syntax with AS builder. The first stage creates the file, the second copies it.

3

Build the Docker image using BuildKit

Run the Docker build command with BuildKit enabled to build the image named buildkit-demo using the Dockerfile in the current directory.

Docker

# syntax=docker/dockerfile:1
FROM alpine AS builder
RUN echo "Hello BuildKit" > /hello.txt

FROM alpine
COPY --from=builder /hello.txt /hello.txt

# Your code here

Need a hint?

Use docker build -t buildkit-demo . to build the image in the current folder.

4

Run the container and display the file content

Run a container from the buildkit-demo image and print the content of /hello.txt to confirm the build was successful.

Docker

# syntax=docker/dockerfile:1
FROM alpine AS builder
RUN echo "Hello BuildKit" > /hello.txt

FROM alpine
COPY --from=builder /hello.txt /hello.txt

docker build -t buildkit-demo .

# Your code here

Need a hint?

Use docker run --rm buildkit-demo cat /hello.txt to show the file content.