Implementation:Bentoml BentoML Buildx Backend

Knowledge Sources	Bentoml_BentoML
Domains	Container, OCI
Last Updated	2026-02-13 15:00 GMT

Overview

Implements the Docker Buildx container builder backend for BentoML, extending the OCIBuilder base class to build OCI images using docker buildx build with support for multi-platform builds and attestations.

Description

The buildx module provides the Docker Buildx backend implementation for BentoML's container build system. It extends the OCIBuilder base class and exports the standard backend interface:

• BUILDKIT_SUPPORT -- Set to True as Buildx uses BuildKit natively.
• BUILD_CMD -- Set to ["buildx", "build"], overriding the default build sub-command.
• health() -- Delegates to Docker's health check first, then verifies that the buildx plugin is installed by checking for "--builder string" in docker buildx --help output.
• supports_attestation() -- Checks the Buildx version (must be > 0.10.0) to determine if attestation features (provenance, SBOM) are supported.
• construct_build_args() -- Builds the CLI argument list with extensive options:
  • platform -- Multi-platform build targets; warns if multiple platforms are used without --push.
  • push/load -- Push to registry or load locally (mutually handled: push disables load).
  • output -- Custom output configuration; local output disables both push and load.
  • add_host, build_arg, build_context, label -- Standard Docker build options.
  • cache_from, cache_to -- Cache import/export configuration.
  • no_cache_filter -- Selective cache invalidation.
  • secret, ulimit -- Build secrets and resource limits.
  • attest, provenance, sbom -- Attestation options (only added if Buildx version supports them).
  • Additional keyword arguments are passed through with underscores replaced by hyphens.

The module reuses ENV and find_binary from the Docker backend.

Usage

Use this backend for advanced Docker builds requiring multi-platform support, BuildKit caching strategies, or supply chain attestation features.

Code Reference

Source Location

• Repository: Bentoml_BentoML
• File: src/bentoml/_internal/container/buildx.py
• Lines: 1-148

Signature

BUILDKIT_SUPPORT = True
BUILD_CMD = ["buildx", "build"]

def health() -> bool: ...
def supports_attestation() -> bool: ...
def construct_build_args(
    *,
    context_path: PathType = ".",
    add_host: dict[str, str] | ArgType = None,
    attest: str | dict[str, str] | ArgType = None,
    build_arg: dict[str, str] | ArgType = None,
    build_context: dict[str, str] | ArgType = None,
    cache_from: str | dict[str, str] | ArgType = None,
    cache_to: str | dict[str, str] | ArgType = None,
    label: dict[str, str] | ArgType = None,
    load: bool = True,
    no_cache_filter: str | dict[str, str] | ArgType = None,
    output: str | dict[str, str] | ArgType = None,
    platform: str | ArgType = None,
    pull: bool = False,
    provenance: str | dict[str, str] | ArgType = None,
    sbom: str | dict[str, str] | ArgType = None,
    push: bool = False,
    secret: str | dict[str, str] | ArgType = None,
    ulimit: str | dict[str, tuple[int, int]] | ArgType = None,
    **kwargs: t.Any,
) -> Arguments: ...

Import

from bentoml._internal.container import buildx

I/O Contract

Inputs

Name	Type	Required	Description
context_path	PathType	No	Build context directory (default: ".")
platform	str or tuple	No	Target platform(s) for multi-platform build
push	bool	No	Push image to registry (default: False)
load	bool	No	Load image into local Docker (default: True)
cache_from	str or dict	No	Cache source configuration
cache_to	str or dict	No	Cache destination configuration
attest	str or dict	No	Attestation configuration (requires Buildx > 0.10.0)
provenance	str or dict	No	Provenance attestation config
sbom	str or dict	No	SBOM attestation config

Outputs

Name	Type	Description
Arguments	Arguments	Constructed CLI argument list for docker buildx build command
bool	bool	Health check or attestation support result

Usage Examples

from bentoml._internal.container import buildx

# Check if docker buildx is available
if buildx.health():
    # Multi-platform build with push
    args = buildx.construct_build_args(
        context_path="/path/to/project",
        platform=("linux/amd64", "linux/arm64"),
        push=True,
        build_arg={"VERSION": "1.0"},
        cache_from={"type": "registry", "ref": "myrepo/cache"},
        tag=("myimage:latest",),
    )

    # Check attestation support
    if buildx.supports_attestation():
        args = buildx.construct_build_args(
            context_path=".",
            provenance={"mode": "max"},
            sbom=True,
        )

Related Pages

• Implementation:Bentoml_BentoML_OCIBuilder_Base
• Implementation:Bentoml_BentoML_Docker_Backend