How to Use Docker BuildKit for Faster, Efficient Builds
To use
docker buildkit, enable it by setting the environment variable DOCKER_BUILDKIT=1 before running docker build. BuildKit improves build speed and caching by running builds with docker build while BuildKit is active.Syntax
The basic syntax to use Docker BuildKit is to enable it via an environment variable and then run the usual docker build command.
DOCKER_BUILDKIT=1: Enables BuildKit for the build.docker build [OPTIONS] PATH: Builds the Docker image from the specified path.
bash
DOCKER_BUILDKIT=1 docker build -t your-image-name .Example
This example shows how to enable BuildKit and build a simple Docker image from a Dockerfile in the current directory.
bash
DOCKER_BUILDKIT=1 docker build -t hello-buildkit .Output
[+] Building 3.0s (7/7) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 37B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/alpine:latest 1.0s
=> [1/3] FROM docker.io/library/alpine:latest 1.0s
=> [2/3] RUN echo 'Hello from BuildKit!' 0.5s
=> [3/3] CMD ["/bin/sh"] 0.5s
=> exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:abcdef1234567890 0.0s
Successfully built abcdef1234567890
Successfully tagged hello-buildkit:latest
Common Pitfalls
Common mistakes when using Docker BuildKit include:
- Not enabling BuildKit by forgetting
DOCKER_BUILDKIT=1. - Using older Docker versions that do not support BuildKit (requires Docker 18.09+).
- Expecting BuildKit features without enabling it explicitly.
Always check your Docker version and enable BuildKit before building.
bash
docker build -t image-name . # Without BuildKit enabled
# Correct way:
DOCKER_BUILDKIT=1 docker build -t image-name .Quick Reference
| Command | Description |
|---|---|
| DOCKER_BUILDKIT=1 docker build -t image-name . | Build image with BuildKit enabled |
| docker build -t image-name . | Build image without BuildKit (legacy) |
| docker build --progress=plain | Show detailed build output with BuildKit |
| docker build --no-cache | Build without using cache, works with BuildKit |
Key Takeaways
Enable BuildKit by setting DOCKER_BUILDKIT=1 before docker build.
BuildKit requires Docker version 18.09 or newer.
BuildKit speeds up builds and improves caching efficiency.
Use --progress=plain to see detailed build logs with BuildKit.
Without enabling, docker build uses the older build engine.