534f179ee6
main was 16 days and 259 commits behind the line the product is actually built on, at contract 0.30.0 against 0.35.0, with no per-PC credential code at all. It was neither current nor curated - just stale. This brings it forward and, at the same time, makes it mean something: main is what a receiving site installs, and nothing else. WHAT IT CARRIES. Twelve plugins - backups, computers, endpoints, guides, knowledgebase, machines, network, notifications, printers, slides, tools, warranty - plus applications, which is manifest-less core and always ships. The only manifest dependency inside that set is endpoints on computers, and both are in it, so the closure is self-contained. WHAT IT DOES NOT. employees, geenforce, measuringtools, printedparts and usb stay on the site line. So do the Windows installer tree, the VM rehearsal helpers, the agent tooling config, one site's data loader, the internal audit and findings records, and the planner spreadsheet. 1,135 tracked files against 1,438. A REMOVAL THAT BREAKS THE APP IS NOT A REMOVAL, and two nearly shipped: deploy/site-profile-universal.json still named all seventeen plugins. It is the file docs/DEPLOY.md tells a site to provision from, so a fresh install would have failed at `flask plugin apply-profile` with PluginError - the first thing a receiving site does, broken by the branch meant to serve them. It now names the twelve that exist, and its comment says the two must agree. agent/ was never refreshed. Whoever populated this branch copied shopdb/, plugins/, frontend/ and tests/ from the site line and left the agent tree at its September state: 22 C# and PowerShell sources missing, including AgentCredentials, EnrollmentService, AgentHttpFactory and the fleet-alert client, plus one file the site line had deleted still present. The old tree is internally consistent, so it compiles, and nothing in CI builds it - every gate was green over a server that speaks enrollment and per-PC credentials to a bundled agent source that cannot. Resynced whole. DECISIONS THIS ENCODES, rather than defers: - The plugin-authoring lab builds printedparts, whose manifest depends on employees, so it could not stay. The lab remains on the site line and main ships no build-along tutorial. That is a real loss for an adopting developer and is recorded here rather than discovered later. - Recognition, Training and Recertification notifications are no longer seeded. Each splits one notification into a card per employee and renders a photo, which needs a plugin this branch does not bundle. Seeding them would offer an author a type that cannot resolve anybody. A site that installs employees gets them from that plugin's own seed. - Windows/IIS is documented as the legacy path throughout, and the README leads with Docker, because that is what a receiving site gets. The API description is regenerated for THIS branch - 347 paths and 483 operations, down from 415 and 573 - so the published contract describes what is here rather than what the site line serves. docs/CONFIG.md lost the two measuring-tool label keys the code no longer declares, which two lanes had decided opposite ways. Suite: 3124 passed, 6 skipped. Naming and style gates pass. The docs gates run rather than skip, and every index line count is derived from the file it names.
132 lines
6.4 KiB
Markdown
132 lines
6.4 KiB
Markdown
<!-- docmeta
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purpose: explanation
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audience: developer
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status: current
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summary: Why each plugin owns its own Alembic chain instead of adding tables to the core chain.
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loadwith: none
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-->
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# ADR-008: Plugin migration ownership (per-plugin chains from the cutover)
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- **Status:** ACCEPTED
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- **Date:** 2026-07-10
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- **Deciders:** ShopDB maintainers
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- **Supersedes:** the "Migration strategy (resolved)" section of ADR-004
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## Context
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ADR-004 resolved a Phase 7B footgun by folding every bundled plugin's tables
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into the single core Alembic chain (migration `7c04_fold_plugin_schema`), and
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later core migrations (`7d04`..`7d16`) kept adding plugin schema directly to the
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core chain. At the time this was the safe choice: bundled-plugin baselines and
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the core baseline had both been creating the same tables, so
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`flask plugin upgrade-all` would collide with `flask db upgrade`.
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That resolution left the per-plugin Alembic engine
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(`shopdb/plugins/migrations.py`, `shopdb/plugins/alembic_template.py`, the
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`alembic_version_<plugin>` version tables, and `flask plugin upgrade-all`) fully
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built but unused for the bundled plugins. The framework is the product (per the
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project's charter); a plugin that cannot own its own schema is not really a
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plugin. Sister sites that adopt or fork a plugin need its schema history to
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travel with the plugin, not be entangled in the host's core chain. Keeping every
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future plugin table change in the core chain also means the core chain grows
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without bound and a plugin can never be cleanly removed.
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The blocker ADR-004 worried about (double table creation) only exists while a
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plugin's own migration tries to CREATE tables the core chain already created.
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That is avoidable: history is immutable, so the tables already built by the core
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chain stay owned by the core chain; only NEW schema needs a new home.
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## Decision
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Ownership splits at a fixed cutover, the current core-chain head.
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1. **Core chain owns history through its head.** The core Alembic chain
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(baseline `68b3947ae14f` .. head `7d16_directoryemployees`) remains
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authoritative for every table that exists at the cutover, including the
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bundled-plugin tables it created. Those migrations are immutable and are not
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rewritten. `flask db upgrade` continues to reproduce the full schema.
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2. **Plugin chains own plugin schema going forward.** From the cutover forward,
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any change to a plugin's schema lands as
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`plugins/<name>/migrations/versions/000N_*.py` in that plugin's own chain,
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never in the core chain. The core chain is reserved for core tables.
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3. **Every table-owning bundled plugin gets a `0001` anchor.** Each such plugin
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carries a migration chain whose first revision is a stamp-only no-op:
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`upgrade()` does nothing because the core chain already created the tables.
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The anchor exists so the plugin chain has a base that
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`flask plugin upgrade-all` can stamp into the per-plugin version table
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`alembic_version_<plugin>`. Blueprint-only plugins that own no tables get no
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chain.
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4. **Deploy and upgrade sequence.** A deploy runs `flask db upgrade`
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(core chain, creates everything through the head) then
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`flask plugin upgrade-all` (stamps every plugin anchor and applies any later
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per-plugin migrations). The same two commands upgrade an existing install;
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both are idempotent. The registry (`instance/plugins.json`) tracks each
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plugin's applied revisions in `migrations_applied`.
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5. **Table-ownership registry.** `PLUGIN_TABLE_OWNERS` in
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`shopdb/plugins/alembic_template.py` is the explicit map of which tables each
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plugin owns; it is kept in sync with the plugins' `__tablename__` declarations
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and pinned by `tests/test_plugin_migrations.py`.
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External (out-of-tree) plugins per ADR-003 already shipped their own chains;
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this ADR brings the bundled plugins onto the same model, so there is one rule
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for all plugins.
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## Consequences
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### Positive
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- A plugin's schema history travels with the plugin. Adopting or forking sites
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get the plugin's migrations, not a slice of someone else's core chain.
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- The core chain stops accreting plugin schema; it stays about core tables.
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- A plugin can be evolved (or, with its own downgrade, removed) independently.
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- The long-built per-plugin Alembic engine is finally exercised on every deploy,
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so it cannot silently rot.
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### Negative / cost
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- Two migrate commands per deploy instead of one. Documented in `docs/DEPLOY.md`
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and `docs/UPGRADE.md`; both are idempotent so the cost is one extra safe call.
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- A plugin author must now put new tables in the plugin chain and register them
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in `PLUGIN_TABLE_OWNERS`, rather than autogenerating into the core chain. The
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`flask plugin new` guidance and this ADR spell that out.
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- The cutover is a discontinuity: tables created before it are core-owned,
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tables created after it are plugin-owned. The line is the core-chain head at
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this ADR's date, recorded here so it is unambiguous.
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### Neutral
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- No schema changes and no data migration: the anchors are no-ops. A fresh
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install and an existing install converge to the same state.
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## Alternatives considered
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1. **Keep everything in the core chain (status quo per ADR-004).** Simplest
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operationally but defeats the plugin-as-product goal: plugin schema cannot
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travel, the core chain grows without bound, and plugins can never be cleanly
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removed. Rejected.
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2. **Rewrite history so plugin tables move out of the core chain into plugin
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`0001` CREATE migrations.** Would make each plugin chain self-contained from
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empty, but breaks the immutability rule, forces every existing site to
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re-run a rewritten chain, and re-introduces the exact double-creation footgun
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ADR-004 fixed. Rejected.
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3. **Anchor that CREATEs tables with `IF NOT EXISTS` guards.** Lets a from-empty
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install build plugin tables from the plugin chain, but then two chains both
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claim the same tables and drift can diverge silently. The no-op anchor keeps
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a single authoritative creator (the core chain) for cutover-era tables.
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Rejected.
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## References
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- ADR-003 (plugin distribution; external plugins already ship chains)
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- ADR-004 (deployment topology; this ADR supersedes its migration-strategy note)
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- `shopdb/plugins/alembic_template.py` (`PLUGIN_TABLE_OWNERS`, shared env runner)
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- `shopdb/plugins/migrations.py`, `shopdb/plugins/cli.py` (`upgrade-all`)
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- `plugins/<name>/migrations/` (per-plugin chains and `0001` anchors)
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- `tests/test_plugin_migrations.py` (ownership + chain + idempotency guards)
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- `docs/DEPLOY.md`, `docs/UPGRADE.md`, `docs/PLUGINS.md` (deploy sequence)
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