---
title: Docker container build driver
description: The Docker container driver runs BuildKit in a container image.
keywords: build, buildx, driver, builder, docker-container
aliases:
- /build/buildx/drivers/docker-container/
- /build/building/drivers/docker-container/
---
The Docker container driver allows creation of a managed and customizable
BuildKit environment in a dedicated Docker container.
Using the Docker container driver has a couple of advantages over the default
Docker driver. For example:
- Specify custom BuildKit versions to use.
- Build multi-arch images, see [QEMU](#qemu)
- Advanced options for [cache import and export](../cache/backends/index.md)
## Synopsis
Run the following command to create a new builder, named `container`, that uses
the Docker container driver:
```console
$ docker buildx create \
--name container \
--driver=docker-container \
--driver-opt=[key=value,...]
container
```
The following table describes the available driver-specific options that you can
pass to `--driver-opt`:
| Parameter | Type | Default | Description |
| --------------- | ------ | ---------------- | --------------------------------------------------------------------------------- |
| `image` | String | | Sets the BuildKit image to use for the container. |
| `memory` | String | | Sets the amount of memory the container can use. |
| `memory-swap` | String | | Sets the memory swap limit for the container. |
| `cpu-quota` | String | | Imposes a CPU CFS quota on the container. |
| `cpu-period` | String | | Sets the CPU CFS scheduler period for the container. |
| `cpu-shares` | String | | Configures CPU shares (relative weight) of the container. |
| `cpuset-cpus` | String | | Limits the set of CPU cores the container can use. |
| `cpuset-mems` | String | | Limits the set of CPU memory nodes the container can use. |
| `network` | String | | Sets the network mode for the container. |
| `cgroup-parent` | String | `/docker/buildx` | Sets the cgroup parent of the container if Docker is using the "cgroupfs" driver. |
| `env.<key>` | String | | Sets the environment variable `key` to the specified `value` in the container. |
Before you configure the resource limits for the container,
read about [configuring runtime resource constraints for containers](../../config/containers/resource_constraints/).
## Usage
When you run a build, Buildx pulls the specified `image` (by default,
[`moby/buildkit`](https://hub.docker.com/r/moby/buildkit)).
When the container has started, Buildx submits the build submitted to the
containerized build server.
```console
$ docker buildx build -t <image> --builder=container .
WARNING: No output specified with docker-container driver. Build result will only remain in the build cache. To push result image into registry use --push or to load image into docker use --load
#1 [internal] booting buildkit
#1 pulling image moby/buildkit:buildx-stable-1
#1 pulling image moby/buildkit:buildx-stable-1 1.9s done
#1 creating container buildx_buildkit_container0
#1 creating container buildx_buildkit_container0 0.5s done
#1 DONE 2.4s
...
```
## Loading to local image store
Unlike when using the default `docker` driver, images built with the
`docker-container` driver must be explicitly loaded into the local image store.
Use the `--load` flag:
```console
$ docker buildx build --load -t <image> --builder=container .
...
=> exporting to oci image format 7.7s
=> => exporting layers 4.9s
=> => exporting manifest sha256:4e4ca161fa338be2c303445411900ebbc5fc086153a0b846ac12996960b479d3 0.0s
=> => exporting config sha256:adf3eec768a14b6e183a1010cb96d91155a82fd722a1091440c88f3747f1f53f 0.0s
=> => sending tarball 2.8s
=> importing to docker
```
The image becomes available in the image store when the build finishes:
```console
$ docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
<image> latest adf3eec768a1 2 minutes ago 197MB
```
## Cache persistence
The `docker-container` driver supports cache persistence, as it stores all the
BuildKit state and related cache into a dedicated Docker volume.
To persist the `docker-container` driver's cache, even after recreating the
driver using `docker buildx rm` and `docker buildx create`, you can destroy the
builder using the `--keep-state` flag:
For example, to create a builder named `container` and then remove it while
persisting state:
```console
# setup a builder
$ docker buildx create --name=container --driver=docker-container --use --bootstrap
container
$ docker buildx ls
NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
container * docker-container
container0 desktop-linux running v0.10.5 linux/amd64
$ docker volume ls
DRIVER VOLUME NAME
local buildx_buildkit_container0_state
# remove the builder while persisting state
$ docker buildx rm --keep-state container
$ docker volume ls
DRIVER VOLUME NAME
local buildx_buildkit_container0_state
# the newly created driver with the same name will have all the state of the previous one!
$ docker buildx create --name=container --driver=docker-container --use --bootstrap
container
```
## QEMU
The `docker-container` driver supports using [QEMU](https://www.qemu.org/)
(user mode) to build non-native platforms. Use the `--platform` flag to specify
which architectures that you want to build for.
For example, to build a Linux image for `amd64` and `arm64`:
```console
$ docker buildx build \
--builder=container \
--platform=linux/amd64,linux/arm64 \
-t <registry>/<image> \
--push .
```
> **Note**
>
> Emulation with QEMU can be much slower than native builds, especially for
> compute-heavy tasks like compilation and compression or decompression.
## Custom network
You can customize the network that the builder container uses. This is useful
if you need to use a specific network for your builds.
For example, let's [create a network](../../engine/reference/commandline/network_create.md)
named `foonet`:
```console
$ docker network create foonet
```
Now create a [`docker-container` builder](../../engine/reference/commandline/buildx_create.md)
that will use this network:
```console
$ docker buildx create --use \
--name mybuilder \
--driver docker-container \
--driver-opt "network=foonet"
```
Boot and [inspect `mybuilder`](../../engine/reference/commandline/buildx_inspect.md):
```console
$ docker buildx inspect --bootstrap
```
[Inspect the builder container](../../engine/reference/commandline/inspect.md)
and see what network is being used:
```console
$ docker inspect buildx_buildkit_mybuilder0 --format={{.NetworkSettings.Networks}}
map[foonet:0xc00018c0c0]
```
## Further reading
For more information on the Docker container driver, see the
[buildx reference](../../engine/reference/commandline/buildx_create.md#driver).