Implementation:Bentoml BentoML Buildah Backend

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

Overview

Implements the Buildah container builder backend for BentoML, extending the OCIBuilder base class to build OCI images using the Buildah CLI tool.

Description

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

• BUILDKIT_SUPPORT -- Set to False since Buildah does not use Docker BuildKit.
• ENV -- Default environment variables: BUILDAH_FORMAT=oci (OCI image format v2) and DOCKER_BUILDKIT=0.
• find_binary() -- Locates the buildah executable using shutil.which.
• health() -- Checks if Buildah is installed and available in PATH.
• construct_build_args() -- Builds the CLI argument list for buildah bud (build-using-dockerfile). Supports the following options:
  • add_host -- Host-to-IP mappings (dict or tuple)
  • annotation -- Image annotations (dict or tuple)
  • label -- Image labels (dict or tuple)
  • build_arg -- Build-time variables (dict or tuple)
  • creds -- Registry credentials (string or dict)
  • decryption_key -- Decryption keys (string or dict)
  • runtime_flag -- Runtime flags (string or dict)
  • secret -- Build secrets (string or dict)
  • ulimit -- Resource limits (string or dict with (soft, hard) tuples)
  • volume -- Volume mounts (string or (host, container, options) tuple)
  • Additional keyword arguments are passed through with underscores replaced by hyphens.

The parse_dict_opt helper formats dictionaries into comma-separated key=value strings for CLI options.

Usage

Use this backend when building OCI container images with Buildah, particularly in rootless or daemonless container build environments.

Code Reference

Source Location

• Repository: Bentoml_BentoML
• File: src/bentoml/_internal/container/buildah.py
• Lines: 1-99

Signature

BUILDKIT_SUPPORT = False
ENV = {"BUILDAH_FORMAT": "oci", "DOCKER_BUILDKIT": "0"}

def find_binary() -> str | None: ...
def health() -> bool: ...
def construct_build_args(
    *,
    context_path: PathType = ".",
    add_host: dict[str, str] | ArgType = None,
    annotation: dict[str, str] | ArgType = None,
    label: dict[str, str] | ArgType = None,
    build_arg: dict[str, str] | ArgType = None,
    creds: str | dict[str, str] | ArgType = None,
    decryption_key: str | dict[str, str] | ArgType = None,
    runtime_flag: str | dict[str, str] | ArgType = None,
    secret: str | dict[str, str] | ArgType = None,
    ulimit: str | dict[str, tuple[int, int]] | ArgType = None,
    volume: str | tuple[str, str, str] | None = None,
    **kwargs: t.Any,
) -> Arguments: ...

Import

from bentoml._internal.container import buildah

I/O Contract

Inputs

Name	Type	Required	Description
context_path	PathType	No	Build context directory (default: ".")
add_host	dict or tuple	No	Extra host-to-IP mappings
annotation	dict or tuple	No	Image annotations
label	dict or tuple	No	Image labels
build_arg	dict or tuple	No	Build-time variables
creds	str or dict	No	Registry credentials
secret	str or dict	No	Build secrets
volume	str or tuple	No	Volume mount specification

Outputs

Name	Type	Description
Arguments	Arguments	Constructed CLI argument list for buildah build command
bool	bool	Health check result
str or None	str or None	Path to buildah binary (from find_binary)

Usage Examples

from bentoml._internal.container import buildah

# Check if buildah is available
if buildah.health():
    # Construct build arguments
    args = buildah.construct_build_args(
        context_path="/path/to/project",
        build_arg={"VERSION": "1.0", "ENV": "production"},
        label={"maintainer": "team@example.com"},
        tag=("myimage:latest",),
    )

Related Pages

• Implementation:Bentoml_BentoML_OCIBuilder_Base
• Implementation:Bentoml_BentoML_Podman_Backend