mirror of https://github.com/docker/docs.git
102 lines
3.9 KiB
Markdown
102 lines
3.9 KiB
Markdown
---
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title: Docker Build architecture
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description: Learn about Docker Build and its components.
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keywords: build, buildkit, buildx, architecture
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---
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Docker Build implements a client-server architecture, where:
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- Buildx is the client and the user interface for running and managing builds
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- BuildKit is the server, or builder, that handles the build execution.
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As of Docker Engine 23.0 and Docker Desktop 4.19, Buildx is the default build
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client.
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## Buildx
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Buildx is a CLI tool that provides a user interface for working with builds.
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Buildx is a drop-in replacement for the legacy build client used in earlier
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versions of Docker Engine and Docker Desktop. In newer versions of Docker
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Desktop and Docker Engine, you're using Buildx by default when you invoke the
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`docker build` command. In earlier versions, to build using Buildx you would
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use the `docker buildx build` command.
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Buildx is more than just an updated `build` command. It also contains utilities
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for creating and managing [builders](#builders).
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### Install Buildx
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Docker Buildx is installed by default with Docker Desktop. Docker Engine
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version 23.0 and later requires that you install Buildx from a separate
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package. Buildx is included in the Docker Engine installation instructions, see
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[Install Docker Engine](../engine/install/index.md).
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You can also build the CLI plugin from source, or grab a binary from the GitHub
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repository and install it manually. See
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[docker/buildx README](https://github.com/docker/buildx#manual-download){: target="blank" rel="noopener"}
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for more information
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## Builders
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"Builder" is a term used to describe an instance of a BuildKit backend.
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A builder may run on the same system as the Buildx client, or it may run
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remotely, on a different system. You can run it as a single node, or as a cluster
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of nodes. Builder nodes may be containers, virtual machines, or physical machines.
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How and where you run your builders depends on your use case. Buildx implements
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a concept of [build drivers](./drivers/index.md) to refer to different types of
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builder configurations. Buildx supports the following drivers:
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- `docker`: uses the BuildKit library bundled into the Docker daemon.
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- `docker-container`: creates a dedicated BuildKit container using Docker.
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- `kubernetes`: creates BuildKit pods in a Kubernetes cluster.
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- `remote`: connects directly to a manually managed BuildKit daemon.
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You can create, append, and connect to builders and nodes using the
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[`docker buildx create` command](../engine/reference/commandline/buildx_create.md).
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## BuildKit
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BuildKit, or `buildkitd`, is the daemon process that executes the build
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workloads.
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A build execution starts with the invocation of a `docker build` command.
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Buildx interprets your build command and sends a build request to the BuildKit
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backend. The build request includes:
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- The Dockerfile
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- Build arguments
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- Export options
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- Caching options
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BuildKit resolves the build instruction and executes the build steps.
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For the duration of the build, Buildx monitors the build status and prints
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the progress to the terminal.
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If the build requires resources from the client, such as local files or build
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secrets, BuildKit requests the resources that it needs from Buildx.
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This is one way in which BuildKit is more efficient compared to the legacy
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builder it replaces. BuildKit only requests the resources that the build needs,
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when they're needed. The legacy builder, in comparison, always takes a copy of
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the local filesystem.
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Examples of resources that BuildKit can request from Buildx include:
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- Local filesystem build contexts
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- Build secrets
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- SSH sockets
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- Registry authentication tokens
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For more information about BuildKit, see [BuildKit](buildkit/index.md).
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## Example build sequence
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The following diagram shows an example build sequence involving Buildx and
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BuildKit.
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