Overview of Docker Build

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Docker Build is one of Docker Engine’s most used features. Whenever you are creating an image you are using Docker Build. Build is a key part of your software development life cycle allowing you to package and bundle your code and ship it anywhere.

Engine uses a client-server architecture and is composed of multiple components and tools. The most common method of executing a build is by issuing a docker build command. The CLI sends the request to Docker Engine which, in turn, executes your build.

There are now two components in Engine that can be used to build an image. Starting with the 18.09 release, Engine is shipped with Moby BuildKit, the new component for executing your builds by default.

BuildKit is the backend evolution from the Legacy Builder, it comes with new and much improved functionality that can be powerful tools for improving your builds’ performance or reusability of your Dockerfiles, and it also introduces support for complex scenarios.

The new client Docker Buildx, is a CLI plugin that extends the docker command with the full support of the features provided by BuildKit builder toolkit. docker buildx build provides the same user experience as docker build with many new features like creating scoped builder instances, building against multiple nodes concurrently, outputs configuration, inline build caching, and specifying target platform. In addition, Buildx also supports new features that are not yet available for regular docker build like building manifest lists, distributed caching, and exporting build results to OCI image tarballs.

Docker Build is way more than a simple build command and is not only about packaging your code, it’s a whole ecosystem of tools and features that support not only common workflow tasks but also provides support for more complex and advanced scenarios:

Building your images

Packaging your software

Bundle and package your code to run anywhere, from your local Docker Desktop, to Docker Engine and Kubernetes on the cloud. To get started with Build, see the Packaging your software page.

Choosing a build driver

Run Buildx with different configurations depending on the scenario you are working on, regardless of whether you are using your local machine or a remote compute cluster, all from the comfort of your local working environment. For more information on drivers, see the drivers guide.

Optimizing builds with cache management

Improve build performance by using a persistent shared build cache to avoid repeating costly operations such as package installations, downloading files from the internet, or code build steps.

Creating build-once, run-anywhere with multi-platform builds

Collaborate across platforms with one build artifact. See Multi-platform images page.

Continuous integration

GitHub Actions

Automate your image builds to run in GitHub actions using the official docker build actions:

Customizing your builds

Select your build output format

Choose from a variety of available output formats, to export any artifact you like from BuildKit, not just docker images. See Set the export action for the build result.

Managing build secrets

Securely access protected repositories and resources at build time without leaking data into the final build or the cache.

Orchestrating builds using Bake

Connect your builds together and easily parameterize your images using buildx bake. See High-level build options with Bake.

Extending BuildKit

Custom syntax on Dockerfile

Use experimental versions of the Dockerfile frontend, or even just bring your own to BuildKit using the power of custom frontends. See also the Syntax directive.

Configure BuildKit

Take a deep dive into the internal BuildKit configuration to get the most out of your builds. See also buildkitd.toml, the configuration file for buildkitd.

build, buildx, buildkit