Investigation
Start by proving artifact identity and signer evidence, not by reading logs.
Safe investigation sequence:
- Verify Digest & Signature: Check the digest and cryptographic signature for the running image.
- Confirm SBOM Match: Ensure the SBOM belongs to the exact same immutable artifact.
- Compare Identities: Compare the runtime identity with the tested promotion target from Chapter 04.
- Review Policy Reports: Check Kyverno or cluster events to see if the artifact was audited or denied.
Containment
Containment is about restoring trust before accelerating the deployment.
Containment steps:
- Restore Known-Good: Roll back to the last known-good, cryptographically verified artifact.
- Re-run Approved Path: Force the signing and attestation through the official CI/CD pipeline.
- Audit Policy: Keep verification policies in
Auditmode until stable results are confirmed. - No Bypasses: Never “temporarily” disable provenance checks to complete a high-pressure release.
Pause and Predict: What automated guardrail would have prevented this incident entirely?