The Complete Production SOP: How to Deploy and Run Docker Buildx Bake Multi-Platform Build Matrices in Autonomous AI Agents

Autonomous agents discover custom toolings and procedural SOPs by indexing designated directory trees within the workspace or user home directory. To install `docker-buildx-bake-matrix`, create the skill directory in `~/.agents/skills/docker-buildx-bake-matrix` (or `.claude/skills` / `.cursor/rules` depending on your active engine) and download the validated SKILL.md. This manifest defines strict invocation constraints, declarative schema validation rules, and sandbox permissions (`fs_read: true`, `fs_write: workspace`, `shell_exec: false`).

---
name: "docker-buildx-bake-matrix"
description: "Build and push multi-architecture (linux/amd64, linux/arm64) images in parallel using Buildx Bake."
metadata:
  author: "Docker"
  version: "1.0.0"
  runtime_compatibility:
    - "codex"
    - "claude-code"
    - "cursor"
    - "windsurf"
triggers:
  - "setup docker buildx multiarch"
  - "configure docker-bake.hcl"
  - "cache buildx to remote registry"
permissions:
  fs_read: true
  fs_write: "workspace"
  shell_exec: false
  net_access: false
---

The default Docker daemon engine builder cannot package multi-platform manifest lists into registry tarballs natively. The agent must construct a container-backed builder using `docker buildx create --driver docker-container`. Next, the agent creates a declarative `docker-bake.hcl` file containing architecture targets, target groups, and distributed cache parameters. This eliminates complex, non-reproducible bash build scripts across CI and local environments.

group "default" {
  targets = ["api"]
}

variable "REGISTRY" {
  default = "ghcr.io/my-org"
}

variable "VERSION" {
  default = "latest"
}

target "api" {
  context = "."
  dockerfile = "Dockerfile"
  platforms = ["linux/amd64", "linux/arm64"]
  tags = ["${REGISTRY}/api:${VERSION}"]
  cache-from = ["type=registry,ref=${REGISTRY}/api:buildcache"]
  cache-to = ["type=registry,ref=${REGISTRY}/api:buildcache,mode=max,image-manifest=true"]
  output = ["type=image,push=true"]
}

Agent runtimes monitor prompt input against the trigger registry declared in SKILL.md. Prompts containing phrases such as 'configure docker-bake.hcl' or 'setup docker buildx multiarch' route execution directly into this skill's verified SOP. When invoking, provide the exact targets, container registries, and architectures required so the agent immediately constructs mathematically correct HCL structures without hallucinating parameters.

# Invocation example using Claude Code CLI
claude "configure docker-bake.hcl for our Node.js microservice targeting linux/amd64 and linux/arm64 with remote cache on ghcr.io"

Before executing long, CPU-intensive compilation steps across multiple emulated architectures, the agent must run validation dry-runs. Buildx Bake includes built-in parse and plan inspection via `docker buildx bake --print`. The agent inspects the emitted JSON to confirm matrix expansion, platform targets, and cache parameters before any image artifact is compiled or pushed.

#!/usr/bin/env bash
set -euo pipefail

echo "==> Validating docker-bake.hcl syntax..."
docker buildx bake --print > /dev/null

echo "==> Inspecting active builder driver..."
BUILDER_DRIVER=$(docker buildx inspect | grep -i "Driver:" | awk '{print $2}')
if [ "$BUILDER_DRIVER" != "docker-container" ]; then
  echo "ERROR: Active builder is not 'docker-container'. Multi-platform builds will fail."
  exit 1
fi

echo "==> Pre-flight checks passed successfully."