TenantAtlas/specs/116-baseline-drift-engine/data-model.md

Phase 1 — Data Model (Baseline Drift Engine)

This document identifies the data/entities involved in Spec 116 and the minimal schema/config changes needed to implement it in this repository.

Existing Entities (Confirmed)

BaselineProfile

Represents a baseline definition.

• Fields (confirmed in migrations): id, workspace_id, name, description, version_label, status, scope_jsonb (jsonb), active_snapshot_id, created_by_user_id, timestamps
• Relationships: has many snapshots; assigned to tenants via BaselineTenantAssignment

BaselineSnapshot

Immutable capture of baseline state at a point in time.

• Fields (confirmed in migrations): id, workspace_id, baseline_profile_id, snapshot_identity_hash, captured_at, summary_jsonb (jsonb), timestamps
• Relationships: has many items; belongs to baseline profile

BaselineSnapshotItem

One item in a baseline snapshot.

• Fields (confirmed in migrations):
  • id, baseline_snapshot_id
  • subject_type
  • subject_external_id
  • policy_type
  • baseline_hash (string)
  • meta_jsonb (jsonb)
  • timestamps

Finding

Generic drift finding storage.

• Fields (confirmed by usage): tenant_id, fingerprint (unique with tenant), recurrence_key (nullable), scope_key, lifecycle fields (first_seen_at, last_seen_at, times_seen), evidence (jsonb)

OperationRun

Tracks long-running operations.

• Fields (by convention): type, status/outcome, summary_counts (numeric map), context (jsonb)

New / Adjusted Data Requirements

1) Inventory sync coverage context

Goal: Baseline compare must know which policy types were actually processed successfully by inventory sync.

Where: operation_runs.context for the latest inventory sync run.

Shape (proposed):

{
  "inventory": {
    "coverage": {
      "policy_types": {
        "deviceConfigurations": {"status": "succeeded", "item_count": 123},
        "compliancePolicies": {"status": "failed", "error": "..."}
      },
      "foundation_types": {
        "securityBaselines": {"status": "succeeded", "item_count": 4}
      }
    }
  }
}

Notes:

• Only summary_counts must remain numeric; detailed coverage lists live in context.
• For Spec 116 v1, it’s sufficient to store policy_types coverage; adding foundation_types coverage at the same time keeps parity with scope rules.

2) Baseline scope schema

Goal: Support both policy and foundation scope with correct defaults.

Current: policy_types only.

Target:

{
  "policy_types": ["deviceConfigurations", "compliancePolicies"],
  "foundation_types": ["securityBaselines"]
}

Default semantics:

• Empty policy_types means “all supported policy types excluding foundations”.
• Empty foundation_types means “none”.

3) Findings recurrence strategy

Goal: Stable identity per snapshot and per subject.

• findings.recurrence_key: populated for baseline compare findings.
• findings.fingerprint: set to the same recurrence key (to satisfy existing uniqueness constraint).

Recurrence key inputs:

• tenant_id
• baseline_snapshot_id
• policy_type
• subject_external_id
• change_type

Grouping (scope_key):

• Keep findings.scope_key = baseline_profile:{baselineProfileId} for baseline compare findings.

4) Inventory meta contract

Goal: Explicitly define what is hashed for v1 comparisons.

• Implemented as a dedicated builder class (no schema change required).
• Used by baseline capture to compute baseline_hash and by compare to compute current_hash.
• Persist the exact contract payload used for hashing to baseline_snapshot_items.meta_jsonb.meta_contract (versioned) for auditability/reproducibility.

Potential Migrations (Likely)

• If baseline_profiles.scope is not jsonb or does not include foundation types → migration to adjust structure (jsonb stays the same, but add support in code; DB change may be optional).
• If coverage context needs persistence beyond operation run context → avoid adding tables unless proven necessary; context-based is sufficient for v1.

Index / Performance Notes

• Findings queries commonly filter by tenant_id + scope_key; ensure there is an index on (tenant_id, scope_key).
• Baseline snapshot items must be efficiently loaded by (baseline_snapshot_id, policy_type).