Atmos SBOM Provenance

Purpose

Use this skill to generate, review, or publish an Atmos software bill of materials (SBOM). Atmos produces a provenance/build-input SBOM: it records evidence used to build or run the selected infrastructure scope. It is not a claim that every deployed workload has been inventoried.

Atmos-managed source receipts (vendor.lock.yaml, including OCI-sourced artifacts) are always included, regardless of --scope. --scope additionally selects one of two adapter groups: the default terraform adds Terraform provider locks and Terraform modules (when the configured command exposes a stable module graph); --scope dependencies instead adds Atmos's own toolchain (.tools/toolchain.lock.yaml) and version-track (versions.lock.yaml) evidence. Helm, Helmfile, discovered deployed images, image package contents, and OpenTofu module graphs are outside this initial scope and must be reported as incomplete or unavailable rather than silently treated as absent.

Related Skills

Need	Load
Immutable vendor receipts, reconciliation, Component Updater PRs	atmos-vendoring
Just-in-time component source workdirs and source receipts	atmos-components
Native CI workflow structure and GitHub Actions runtime setup	atmos-ci
Toolchain locks and configured Terraform/OpenTofu commands	atmos-toolchain
Version-track locks	atmos-version

Generate an SBOM

Generate CycloneDX JSON to stdout, or write either supported format to a reviewed output file:

atmos sbom generate --format cyclonedx-json
atmos sbom generate --format spdx-json --output sbom.spdx.json
atmos sbom generate --include-files --output sbom.cyclonedx.json

--include-files expands the output with the vendor receipt's installation-file relationships; omit it for the normal artifact-oriented output.

The result is derived from evidence, not guesses:

vendor.lock.yaml records immutable Git commits, OCI manifest digests, or verified content hashes and the installed-file inventory for vendor.yaml, component.yaml, and mixin installs.
Just-in-time component workdirs contribute local immutable-resolution receipts; they do not create a committed vendor lock.
.terraform.lock.hcl is authoritative for the selected provider versions and checksums.
Atmos invokes the configured Terraform command (or terraform when none is configured) as modules -json; this requires Terraform 1.10+ and an initialized component directory.

Never insert a checksum, purl, supplier, source URL, or module inventory by inference. Missing evidence must remain NOASSERTION or appear as an explicit coverage diagnostic.

Provenance and NTIA Modes

The default is --mode provenance, which renders available evidence with coverage diagnostics:

atmos sbom generate --scope terraform --mode provenance --format cyclonedx-json

Use --mode ntia only when a declared subject is available and every adapter required for the selected Terraform scope reports complete coverage:

atmos sbom generate \
  --scope terraform \
  --mode ntia \
  --subject-name infra-live \
  --subject-version "$(git rev-parse --short HEAD)" \
  --subject-supplier "Cloud Posse, LLC" \
  --format spdx-json \
  --output infra-live.sbom.spdx.json

NTIA mode must fail—not downgrade silently—when the subject is incomplete, a provider lock lacks the required SHA-256 evidence, a module is not immutably resolved, or the module graph command is unavailable. A configured OpenTofu command is honored, but its module inventory is unavailable unless it implements the same stable JSON interface.

Native CI Publication

--upload publishes the already-generated document through the detected native CI provider. The document remains the source of truth and is still written to stdout or --output.

In GitHub Actions, publication stores a workflow artifact via the Actions runtime API. Add the runtime action before the Atmos command:

permissions:
  contents: read

steps:
  - uses: actions/checkout@v6
  - uses: cloudposse/atmos/actions/github-runtime@v1
    with:
      mode: env
  - run: atmos sbom generate --format spdx-json --output sbom.spdx.json --upload
    env:
      GITHUB_TOKEN: ${{ github.token }}

Do not claim that this uploads dependencies to GitHub Dependency Graph. GitHub's SBOM APIs can export or request GitHub-generated reports, but do not accept arbitrary submitted SBOMs. The correct result is a retained, auditable workflow artifact.

Safe Output Rules

SBOM output must not contain absolute filesystem paths, credentials, tokens, or signed URLs.
Source references are credential-free and use immutable resolved evidence where available.
File-level data is opt-in through --include-files.
Preserve coverage diagnostics in the output; a missing domain is a finding, not a zero-dependency result.

SKILL.md