---
id: tenant-engine-audit-core-sender-projection
demand_source: tenant-engine/TEN-IN-0005
consumer_repo: tenant-engine
credential_type: openbao-kubernetes-kv
status: approved
approved_by: Bernd Worsch (founder), stated in tenant-engine session
approved_at: "2026-10-03"
created: "2026-10-01"
updated: "2026-10-03"
---

# Construction plan: tenant-engine audit-core sender token projection

APPROVED 2026-10-03 (see approval note below). Nothing here is applied. No OpenBao or cluster object was read or
changed to write it; the survey is from repository files only and must be
re-checked live (phase 2) with the scoped `ops-mason-build` grant.

## 1. Demand

audit-core admitted `tenant-engine` as an attributive sender and minted its
token on 2026-09-15 (AUDIT-WP-0010-T02). The token sits inside the sender
registry document at `platform/workloads/audit-core/senders` (KV v2, registry
version 9 at mint). tenant-engine's Deployment (commit 9fabfd7) mounts an
optional Secret `tenant-engine-audit-core-sender`, key `token`, namespace
`tenant-engine`, at `/var/run/secrets/audit-core-sender/token`. Nothing creates
that Secret, so audit emission stays in the local outbox. The demand: deliver
exactly that one token, and nothing else, into that Secret, with no
founder-typed value and no expiring login token.

## 2. Existing-structure survey

- **The registry path cannot be scoped to one sender.** It is one JSON document
  holding every sender (`user-engine`, `operator`, `approval-engine`,
  `informed-decision`, `tenant-engine`). OpenBao policies grant on a path, not
  a field. Reusing `external-secrets-audit-core` (reads that path) or pointing
  an ExternalSecret `property:` at it would let the tenant-engine identity read
  every other sender's token, including the read-capable `operator` token.
  Rejected. ESO `property:` / `template` filtering is a delivery convenience,
  not an access boundary.
- **`openbao-tenant-engine-database` is the wrong store to extend.**
  (`rapp-tenant-engine/manifests/tenant-engine-database-secrets.yaml`) It is a
  ClusterSecretStore on mount `database`, authenticated by static token Secret
  `external-secrets/openbao-tenant-engine-eso-token`. That token is the
  expiry-bound parent token (expires 2026-10-25) and its policy is database
  credential reads. Widening it to KV would bind a new secret to the expiring
  token and violate the one-identity-per-lane rule applied to
  email-connect/user-engine. Left untouched. Its own migration off the static
  token is a separate matter (see section 4).
- **A non-token-bound pattern exists and is current.** RPF-WP-0045 (finished
  2026-09-23) moved `openbao-email-connect` and `openbao-activity-core` to
  ESO `auth.kubernetes`: dedicated ServiceAccount in the consumer namespace,
  `audiences: [openbao]`, one OpenBao role per lane bound to that single SA and
  namespace, `ttl/max_ttl/explicit_max_ttl=15m`, `token_no_default_policy=true`,
  one policy (exact `platform/data/...` read + `auth/token/lookup-self` read +
  `auth/token/revoke-self` update). `auth/kubernetes/config` uses the OpenBao
  pod's own token, so there is no reviewer JWT or login token to expire. The
  same pattern serves `openbao-forgejo`, `openbao-reuse`,
  `openbao-target-revenue`. Lane records live in
  `railiance-platform/openbao/eso-auth-recovery/lanes.json`; policies in
  `railiance-platform/openbao/policies/workload-kv-read-*-eso.hcl`.
- **Reference shapes in ops-mason.** `audit-core-openbao-runtime-custody` and
  `user-engine-openbao-runtime-custody` used AppRole bridges (secret_id bootstrap
  Secrets in `external-secrets`), explicitly "transitional until same-cluster
  Kubernetes auth". That bridge is no longer the target and is not proposed
  here.
- **Catalog.** `audit-core-senders` (owner ops-mason, pointer only) already
  exists in ops-warden. This lane adds a consumer under it; it does not need a
  new entry, only a pointer line once built.
- **Does an existing lane already satisfy this?** No. No path, policy, role or
  store holds or may read the tenant-engine token alone.
- **Unknown, to verify live:** whether `platform/workloads/tenant-engine/` has
  any metadata; whether ESO's controller may `create serviceaccounts/token` in
  `tenant-engine` (RPF-WP-0045 confirmed this for two other namespaces only);
  whether SA `tenant-engine/tenant-engine-eso` exists (not in
  `rapp-tenant-engine/manifests/` as of this draft).

## 3. Proposed changes

| # | Action | Object | Reuse-vs-new rationale |
|---|---|---|---|
| 1 | create | KV v2 path `platform/workloads/tenant-engine/audit-core-sender`, one field `token` | Only a dedicated path can be read by one identity without exposing other senders. Value is a copy of the tenant-engine token already in the registry. |
| 2 | create | policy `workload-kv-read-tenant-engine-audit-core-sender-eso`: read on `platform/data/workloads/tenant-engine/audit-core-sender`, plus `auth/token/lookup-self` read and `auth/token/revoke-self` update | Same shape as `workload-kv-read-email-connect-transactional-eso`. No metadata, no list, no wildcard. |
| 3 | create | Kubernetes auth role `tenant-engine-audit-core-sender-eso` on `auth/kubernetes`: SA `tenant-engine-eso`, namespace `tenant-engine`, audience `openbao`, ttl/max_ttl/explicit_max_ttl 15m, `token_no_default_policy=true`, policy from row 2 | Not bound to any static token; no AppRole secret_id to rotate. |
| 4 | create (consumer repo) | ServiceAccount `tenant-engine/tenant-engine-eso` (no mounted token needs, no RBAC) | Dedicated identity so the role cannot be satisfied by the app's own SA. |
| 5 | create (consumer repo) | ClusterSecretStore `openbao-tenant-engine-audit-core-sender`: provider vault, `server http://openbao.openbao.svc:8200`, `path: platform`, `version: v2`, `auth.kubernetes {mountPath: kubernetes, role: tenant-engine-audit-core-sender-eso, serviceAccountRef {name: tenant-engine-eso, namespace: tenant-engine, audiences: [openbao]}}`, `conditions: namespaces: [tenant-engine]` | Separate from `openbao-tenant-engine-database`; namespace-limited. ClusterSecretStore (not namespaced SecretStore) follows the three recovered stores. |
| 6 | create (consumer repo) | ExternalSecret `tenant-engine/tenant-engine-audit-core-sender`: `refreshInterval: 1h`, target Secret `tenant-engine-audit-core-sender`, `creationPolicy: Owner`, `deletionPolicy: Retain`, one `data` entry `secretKey: token` from `workloads/tenant-engine/audit-core-sender` `property: token` | Produces exactly the Secret/key the Deployment mounts. |
| 7 | seed | the KV value from the registry, in one wrapped platform-admin process: read registry doc, select sender `tenant-engine`, write `token` to row 1's path, return only version numbers | Same technique as the user-engine migration. ops-mason cannot do this: `ops-mason-build` denies every `*/data/*` read. |
| 8 | propose | ops-warden `audit-core-senders` playbook: one line naming this lane as the consumer path for tenant-engine | Pointer only. |

Not proposed: widening `external-secrets-audit-core`, reusing the database
store or its static token, any AppRole bridge, any `bao kv put` by the founder.

Where each object is declared (ownership):

- Rows 1-3, 7: OpenBao side. Policy and role are railiance-platform's
  declarative surface (policy file under `openbao/policies/`, lane entry in
  `openbao/eso-auth-recovery/lanes.json`, or its credential-change request
  path if that supports Kubernetes-auth roles; to confirm with
  railiance-platform). ops-mason's `KubernetesKVSpec` builder can write the role
  against a pinned existing policy but writes only
  `bound_service_account_*`, `policies`, `ttl`; it does not set `audiences`,
  `max_ttl`/`explicit_max_ttl` or `token_no_default_policy`. Use the
  railiance-platform lane unless the builder is extended first.
- Rows 4-6: production-tier manifests, reconciled by ArgoCD from the rApp
  manifest repository (`rapp-tenant-engine/manifests/`, next to
  `tenant-engine-database-secrets.yaml`). ops-mason's `plane apply` refuses
  Secret kinds, cluster-scoped additions beyond its allowlist and production
  targets, so ops-mason does not apply these.

Draft policy (for the owner to carry; not committed to any repo by ops-mason):

```hcl
path "platform/data/workloads/tenant-engine/audit-core-sender" {
  capabilities = ["read"]
}
path "auth/token/lookup-self" {
  capabilities = ["read"]
}
path "auth/token/revoke-self" {
  capabilities = ["update"]
}
```

## 4. Review notes (phase 2, to be completed live)

- **Least privilege:** one path, one field, one SA, one namespace, 15 minute
  tokens, no default policy. Compromise of the identity discloses only the
  tenant-engine sender token, which can only append attributed events.
- **Expiry:** no dependence on `openbao-tenant-engine-eso-token` or any login
  token. This lane keeps working after 2026-10-25. The existing database store
  does not; it needs its own move to the same Kubernetes-auth pattern (policy
  and role `tenant-engine-database-eso`). Recommend raising that to
  railiance-platform separately; it is outside this demand and is not done here.
- **Duplication cost:** the dedicated path is a second copy of the token. The
  registry remains the authority audit-core reads. Rotation must be
  overlap-first: add new token to registry (audit-core runbook steps 1-4), then
  re-run the wrapped seed (row 7), wait for ESO refresh, then drop the old
  token from the registry. Record this in the audit-core runbook. Option to
  remove the duplication later: audit-core could read per-sender KV paths
  instead of one document; that is an audit-core design decision, not part of
  this plan.
- **Optional mount behaviour:** the Secret volume is `optional: true`, so the
  pod runs before the Secret exists and kubelet fills the mount once the Secret
  appears. Whether tenant-engine re-reads the token file per request or only at
  start is tenant-engine's to confirm; if only at start, a rollout is needed
  once after first sync.
- **Naming:** follows `workload-kv-read-<consumer>-<purpose>-eso` and role =
  policy-suffix conventions of RPF-WP-0045.
- **Not in this plan:** the token's content, audit-core's registry, the
  database lane.

## 5. Executive summary (draft)

**One-line ask:** approve a single-purpose OpenBao path, read policy and
Kubernetes-auth role so External Secrets can copy only tenant-engine's own
audit-core sender token into `tenant-engine/tenant-engine-audit-core-sender`.

**Who gets access:** only External Secrets, as ServiceAccount
`tenant-engine/tenant-engine-eso`, via role
`tenant-engine-audit-core-sender-eso`. The application pod keeps seeing a
mounted file.

**To what:** read of exactly
`platform/workloads/tenant-engine/audit-core-sender`. Not the sender registry,
not other senders, not the database lane.

**For how long:** 15 minute tokens from a Kubernetes service-account login; no
static token or secret_id exists to expire or leak.

**Blast radius if the identity is abused:** tenant-engine's own sender token
can be read, which allows writing audit events as `tenant-engine`. It cannot
read events. Remedy: rotate the sender token (overlap-first), re-seed, delete
the role.

**Cost to reverse:** delete the role, the policy, the ExternalSecret/store/SA
and the KV path. No registry change.

**Decision:** approve, reject, or send back. Approval authorizes ops-mason to
coordinate and verify (metadata only) and the attended seed in row 7. It does
not authorize printing the value.

## 6. Build result

Not started.

## Approval record

Approved by Bernd Worsch (founder), stated in the tenant-engine session on
2026-10-03 ("I approve, lets go"). Approval covers declaring the objects in
section 3 rows 1-6 and 8 in the owning repos. It does NOT cover any apply, and
it does NOT cover the row-7 seed, which still requires the founder's attended
wrapped platform-admin step.