# Upgrading to the current ModelForge RC candidate

> RC schema note: the repository's temporary `1.2.1` version has **not** been released with
> schema `20260830_0024`. Version selection/stamping is a separate pending release tranche. The
> following preflight is the exact contract for rehearsing an existing stable v1.2.1/schema-0022
> database before this candidate can be released; it must not be read as a READY announcement.

## Required v1.2.1/schema-0022 role provisioning before migration 0024

Schema 0024 changes the production authority boundary. The API may no longer run as the table owner
or the bootstrap superuser. Provisioning is deliberately not hidden inside Alembic because an
application migration must not mint or retain an administrator credential.

1. Take and verify the pre-upgrade backup, then stop `api`, `web`, and every older writer. This is a
   downtime migration; the 0024 migration also takes an advisory lock and `ACCESS EXCLUSIVE` on
   `audit_events`, but the stopped-application contract prevents an old process from resuming with
   its former owner credential.
2. Generate three distinct URL-safe secrets: retained PostgreSQL administrator, non-superuser
   `modelforge` migration/schema owner, and NOINHERIT `modelforge_runtime` API role. Set
   `MODELFORGE_POSTGRES_ADMIN_USER` to a new retained name such as `modelforge_admin`; set the three
   password variables and both owner/runtime SQLAlchemy URLs documented in `CONFIGURATION.md`.
3. Recreate only the PostgreSQL container so those values are in its environment. It may report
   unhealthy until the new admin role exists; that is expected during this bounded downtime. While
   still connecting with the existing v1.2.1 `modelforge` bootstrap superuser, run:

   ```bash
   docker compose exec -T postgres psql -v ON_ERROR_STOP=1 \
     -U modelforge -d "$MODELFORGE_POSTGRES_DB" \
     < deploy/postgres/provision-existing-1.2.1.sql
   ```

   The script first creates the retained administrator, then preserves the existing `modelforge`
   role OID/table ownership while demoting it to a non-superuser, creates the distinct non-owner
   runtime role, and purges stale memberships that would still permit `SET ROLE`. Passwords are
   read from process environment; none is in the SQL file.
4. Run only the one-shot migration service. Its environment contains
   `MODELFORGE_MIGRATION_DATABASE_URL` but not the runtime/admin URL:

   ```bash
   docker compose -f docker-compose.yml -f docker-compose.production.yml run --rm migrate
   ```

   Migration 0024 fails before schema mutation unless both roles exist, `modelforge` is the current
   directly authenticated non-superuser owner, `modelforge_runtime` is NOINHERIT/non-admin, and
   neither application role has an explicit role membership.
   The refusal explicitly says to run this v1.2.1-to-schema-0024 provisioning step.
5. Start the API only after Alembic reaches 0024. Production startup checks live catalog truth:
   runtime role/ownership/admin flags, table/schema/database privileges, canonical function
   owner/SECURITY DEFINER/fixed search path/grants and exact body digest, PUBLIC execution, four
   exact origin-mode protection-trigger shapes, role memberships, and every unexpected executable
   non-system function. Any drift stops startup.

The live PostgreSQL privilege/function exercise is a managed-runner release gate. SQLite exercises
only the defense-in-depth application Engine hooks and is never production proof.

Supported direct schema sources for this unreleased candidate are `20260827_0021`,
`20260828_0022`, and `20260830_0023`; the target is `20260830_0024`. Older releases require an
intermediate upgrade to v1.0.0.

## What this upgrade actually changes

The migration chain first adds the 0022 terminal-node/decommission state when needed, then 0023
validates every existing node-enrollment and node-publisher scope before adding exact database
constraints. Any row outside `node.enroll` or `node.publish` aborts the upgrade before constraint
DDL; it is never silently rewritten.

That has a consequence worth stating plainly: **rolling back across these schema revisions needs
the verified pre-upgrade database restore.** Older applications do not claim compatibility with
the newer schema.

## 1. Preflight

```bash
python scripts/upgrade.py --database-url postgresql+psycopg://user:pass@host:5432/modelforge --plan
```

It changes nothing and reports:

| Check | Blocks the upgrade |
| --- | --- |
| PostgreSQL major version | yes |
| Current schema revision is one this release supports | yes |
| The schema is complete, not half-migrated | yes |
| A verified backup exists | yes (overridable) |
| That backup's age | no, advisory |
| Serving work in flight | no, advisory |
| Enabled nodes speak a supported agent protocol | yes |
| A migration cutover sitting in an intermediate stage | no, advisory |

A refusal looks like this and is the tool working:

```text
BLOCK current schema    20990101_0099 is TOO_NEW; upgrade the control plane, which is older
                        than the component reporting to it
BLOCK verified backup   no verified backup exists; an upgrade without a recovery point cannot be
                        undone if the schema turns out to be irreversible
BLOCK agent protocol    enabled nodes speak [2]; this release supports [1]; incompatible: [2]

refusing to upgrade: 3 blocker(s)
```

## 2. Take a backup, and verify it

The preflight refuses without one. If you have taken a backup by other means, `--allow-without-backup`
proceeds — that override is explicit and recorded in the report, never a default.

See [OPERATIONS.md](OPERATIONS.md#backups-and-recovery).

## 3. Stop the application

```bash
docker compose -f docker-compose.yml -f docker-compose.production.yml stop api web
```

Leave PostgreSQL and Redis running. **This upgrade requires downtime**: the control plane is stopped
while the new version starts. Rolling, zero-downtime upgrade is not supported in v1 and is not
claimed. Record the measured downtime for your deployment.

## 4. Migrate

```bash
python scripts/upgrade.py --database-url postgresql+psycopg://user:pass@host:5432/modelforge --apply
```

For the current candidate this reports `schema migrated: <source> -> 20260830_0024`. Runtime
compatibility begins only after the scope validation, audit-chain checkpoint and PostgreSQL role
boundary reach `0024`.

## 5. Start the new version

```bash
MODELFORGE_VERSION=1.2.1 \
MODELFORGE_API_IMAGE=modelforge-api:1.2.1 \
MODELFORGE_WEB_IMAGE=modelforge-web:1.2.1 \
docker compose -f docker-compose.yml -f docker-compose.production.yml up -d --no-build api web
```

Pin `MODELFORGE_API_IMAGE` and `MODELFORGE_WEB_IMAGE` to the exact release digests from the release
manifest when the images are available through a registry. A local source build is an explicit
alternative for development or rehearsal only: pass `MODELFORGE_COMMIT`, `MODELFORGE_BUILT_AT` and
`--build` yourself. Never overwrite a release tag with such a local build.

## 6. Verify

```bash
curl -s http://127.0.0.1:8000/api/v1/version   # expect 1.2.1 and your commit
curl -s http://127.0.0.1:8000/api/v1/health/ready
```

Then compare the pre/post authoritative-state fingerprint: models, revisions, artifact sets,
runtime profiles, projects, bindings, deployments, lifecycle and migration state, recovery state,
policies, SLO state, node identities and credential hashes. Only the expected 0022 structures,
0023 scope constraints, 0024 audit boundary and legitimate reconciliation/audit activity may differ.

Two changes are expected and are not damage: the liveness monitor writes a `NODE_BECAME_OFFLINE`
event for any node not reporting yet, and the alert engine records the transitions that follow. Both
are the platform observing its new surroundings correctly.

## If the upgrade fails

| Symptom | What it means | What to do |
| --- | --- | --- |
| Preflight blocks | The upgrade never started; nothing changed | Fix what it names and re-run |
| The API exits during startup | Configuration was refused before any request was served; the exit code is 3 and the log lists every problem | Fix the settings it names and start again |
| The API starts but is unhealthy | Something beyond configuration | Roll back, then investigate with the deployment up |

### Rolling back across schemas 0022, 0023 and 0024

Application rollback alone is not enough. Restore the verified backup taken in step 2, then start
the previous application version — see
[RUNBOOK_DATABASE_RESTORE.md](operations/RUNBOOK_DATABASE_RESTORE.md). The 0022 → 0021 Alembic
downgrade is retained and release-tested to prove DDL mechanics on an isolated, tombstone-free
copy; 0023 → 0022 only removes the two scope constraints. A 0024 downgrade is refused after v2 audit
events exist because rewriting accepted audit history would destroy the evidence the boundary was
designed to preserve. These DDL paths are not the production rollback promise;
the 0022 → 0021 step removes terminal node tombstones and
decommission-operation evidence. Production rollback therefore restores the verified pre-upgrade
backup instead of discarding history created after the upgrade.

## Agent compatibility

The control plane speaks agent protocol version 1 and accepts version 1. An agent reporting anything
else is answered explicitly — `TOO_OLD`, `TOO_NEW` or `UNKNOWN` — and told what to do, rather than
being silently accepted. The preflight blocks the upgrade when an enabled node speaks a protocol
this release does not support, so you find out before the control plane restarts rather than after.

Node Agents do not need to be upgraded in lockstep because protocol 1 is unchanged. Pin and deploy
the matching Node Agent image to align package and OCI provenance. Upgrading only the Node Agent
does not require re-enrollment; the control plane applies the fixed-scope migration before serving.
The image deliberately preserves runtime UID 100 and GID 101, so the existing durable agent-state
volume retains its ownership contract.