Docker

Docker Bake: The Smarter Way to Build Multiple Docker Images

What is Docker Bake?

Docker Bake is a powerful utility introduced by Docker as part of the docker buildx plugin. Inspired by tools like make and docker-compose, Docker Bake lets you define and run multiple Docker builds in parallel using a single configuration file (docker-bake.hcl or docker-bake.json).

If you're managing multiple Docker images, especially in a microservices setup, Docker Bake simplifies your build process dramatically.

Why Should You Use Docker Bake?

  • Build multiple images simultaneously (parallel Docker builds)
  • Define build matrices for multi-platform Docker builds
  • Centralize build configurations in a single file
  • Boost CI/CD pipeline speed and consistency
  • Ideal for monorepos and microservices

In short, Docker Bake is your go-to tool when you want to automate Docker builds across services or platforms.

🎥 Prefer to Watch Instead of Read?

Dive into this practical video tutorial that walks you through everything you need to know about Docker Bake — from setup to advanced build strategies.

How Does Docker Bake Work?

Docker Bake works using a special configuration file: docker-bake.hcl.

Basic Structure of a docker-bake.hcl File:

group "default" {
targets = ["frontend", "backend"]
}

target "frontend" {
context = "./frontend"
dockerfile = "Dockerfile"
tags = ["myapp/frontend:latest"]
}

target "backend" {
context = "./backend"
dockerfile = "Dockerfile"
tags = ["myapp/backend:latest"]
}

💡 Pro Tip: Use .hcl format for better readability and structure when defining complex build targets or build matrices.

How to Use Docker Bake (Command)

The basic command is:

# Run the Docker Bake command
$ docker buildx bake

You can also specify a target or group:

# Build only the backend target
$ docker buildx bake backend

# Use a custom HCL file for the build
$ docker buildx bake --file my-bake-file.hcl

Common Flags:

--push: Push images to a remote registry
--load: Load the image into the local Docker daemon
--set: Override configuration dynamically
--no-cache: Disable cache during build

Docker Bake for Multi-Platform Builds

🔧 One of Docker Bake’s top features is multi-platform support.

You can define a build matrix like this:

target "backend" {
context = "./backend"
platforms = ["linux/amd64", "linux/arm64"]
tags = ["myapp/backend:multi"]
}

Then run:

$ docker buildx bake --push

🚀 Result: A multi-architecture Docker image published to your registry in one go.

Tips & Tricks to Optimize Your Docker Bake Usage

1. Use .dockerignore effectively
Avoid copying unnecessary files during the build phase to improve speed and reduce image size.
2. Leverage Build Cache
Enable BuildKit and reuse Docker layers across builds and targets to save time and resources.
3. Dynamic Overrides with --set
Easily override tags, platforms, or build settings dynamically:
docker buildx bake --set backend.tags=myapp/backend:v2
4. Combine with CI/CD Pipelines
Integrate Docker Bake with GitHub Actions, GitLab CI, or CircleCI for clean, multi-platform build workflows.

Docker Bake vs Docker Compose

Feature Docker Bake Docker Compose
Build multiple images ✅ Yes ✅ Yes
Define matrix builds ✅ Yes ❌ No
Parallel builds ✅ Native Support ❌ No
Focus Build automation Service orchestration

Use Docker Compose for service coordination, and Docker Bake for efficient build orchestration.

Final Thoughts: Should You Start Using Docker Bake?

Absolutely. Whether you’re working on a monorepo, building multi-platform containers, or simply tired of managing multiple docker build commands—Docker Bake is a game-changer.

It’s the smarter, faster, and cleaner way to build multiple Docker images, especially in modern Cloud Native and DevOps pipelines.

Useful Resources

🔗 Docker Bake Official Docs

🔧 Learn Docker Buildx

🟡 If you’re new to containers, consider starting with the basics — learn Docker and containerization to build a strong foundation.

👉 Start here with KodeKloud’s Docker for Beginners course →

Nimesha Jinarajadasa

• 2 min read