buildx/docs/reference/buildx_create.md

buildx create

Usage:  docker buildx create [OPTIONS] [CONTEXT|ENDPOINT]

Create a new builder instance

Options:
      --append                   Append a node to builder instead of changing it
      --builder string           Override the configured builder instance
      --buildkitd-flags string   Flags for buildkitd daemon
      --config string            BuildKit config file
      --driver string            Driver to use (available: [docker docker-container kubernetes])
      --driver-opt stringArray   Options for the driver
      --leave                    Remove a node from builder instead of changing it
      --name string              Builder instance name
      --node string              Create/modify node with given name
      --platform stringArray     Fixed platforms for current node
      --use                      Set the current builder instance

Description

Create makes a new builder instance pointing to a docker context or endpoint, where context is the name of a context from docker context ls and endpoint is the address for docker socket (eg. DOCKER_HOST value).

By default, the current docker configuration is used for determining the context/endpoint value.

Builder instances are isolated environments where builds can be invoked. All docker contexts also get the default builder instance.

Examples

Append a new node to an existing builder (--append)

The --append flag changes the action of the command to append a new node to an existing builder specified by --name. Buildx will choose an appropriate node for a build based on the platforms it supports.

Examples

$ docker buildx create mycontext1
eager_beaver

$ docker buildx create --name eager_beaver --append mycontext2
eager_beaver

Specify options for the buildkitd daemon (--buildkitd-flags)

--buildkitd-flags FLAGS

Adds flags when starting the buildkitd daemon. They take precedence over the configuration file specified by --config. See buildkitd --help for the available flags.

Example

--buildkitd-flags '--debug --debugaddr 0.0.0.0:6666'

Specify a configuration file for the buildkitd daemon (--config)

--config FILE

Specifies the configuration file for the buildkitd daemon to use. The configuration can be overridden by --buildkitd-flags. See an example buildkitd configuration file.

Set the builder driver to use (--driver)

--driver DRIVER

Sets the builder driver to be used. There are two available drivers, each have their own specificities.

• docker - Uses the builder that is built into the docker daemon. With this driver, the --load flag is implied by default on buildx build. However, building multi-platform images or exporting cache is not currently supported.
• docker-container - Uses a buildkit container that will be spawned via docker. With this driver, both building multi-platform images and exporting cache are supported. However, images built will not automatically appear in docker images (see build --load).
• kubernetes - Uses a kubernetes pods. With this driver, you can spin up pods with defined buildkit container image to build your images.

Set additional driver-specific options (--driver-opt)

--driver-opt OPTIONS

Passes additional driver-specific options. Details for each driver:

• docker - No driver options
• docker-container

  • image=IMAGE - Sets the container image to be used for running buildkit.

  • network=NETMODE - Sets the network mode for running the buildkit container.

  • Example:

    --driver docker-container --driver-opt image=moby/buildkit:master,network=host
    

• kubernetes
  • image=IMAGE - Sets the container image to be used for running buildkit.
  • namespace=NS - Sets the Kubernetes namespace. Defaults to the current namespace.
  • replicas=N - Sets the number of Pod replicas. Defaults to 1.
  • nodeselector="label1=value1,label2=value2" - Sets the kv of Pod nodeSelector. No Defaults. Example nodeselector=kubernetes.io/arch=arm64
  • rootless=(true|false) - Run the container as a non-root user without securityContext.privileged. Using Ubuntu host kernel is recommended. Defaults to false.
  • loadbalance=(sticky|random) - Load-balancing strategy. If set to "sticky", the pod is chosen using the hash of the context path. Defaults to "sticky"

Remove a node from a builder (--leave)

The --leave flag changes the action of the command to remove a node from a builder. The builder needs to be specified with --name and node that is removed is set with --node.

Examples

$ docker buildx create --name mybuilder --node mybuilder0 --leave

Specify the name of the builder (--name)

--name NAME

The --name flag specifies the name of the builder to be created or modified. If none is specified, one will be automatically generated.

Specify the name of the node (--node)

--node NODE

The --node flag specifies the name of the node to be created or modified. If none is specified, it is the name of the builder it belongs to, with an index number suffix.

Set the platforms supported by the node

--platform PLATFORMS

The --platform flag sets the platforms supported by the node. It expects a comma-separated list of platforms of the form OS/architecture/variant. The node will also automatically detect the platforms it supports, but manual values take priority over the detected ones and can be used when multiple nodes support building for the same platform.

Examples

$ docker buildx create --platform linux/amd64
$ docker buildx create --platform linux/arm64,linux/arm/v8

Automatically switch to the newly created builder

The --use flag automatically switches the current builder to the newly created one. Equivalent to running docker buildx use $(docker buildx create ...).