Files
shopdb-flask/docs/adr/ADR-002-plugin-versioning.md
cproudlock 534f179ee6 Make main the lean product a site receives
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.
2026-09-19 11:24:40 -04:00

4.0 KiB

ADR-002: Plugin contract versioning

  • Status: ACCEPTED
  • Date: 2026-05-08
  • Deciders: ShopDB maintainers
  • Supersedes: none

Context

Once sister sites start writing their own plugins (or pulling community plugins), the framework's plugin contract becomes a public API. Without a versioning story, any change to BasePlugin or the core platform models can silently break installed plugins at remote sites.

The existing BasePlugin and PluginMeta already declare a core_version field (default ">=1.0.0"), but it is not enforced anywhere. The plugin loader does not check it before instantiation.

Decision

The framework adopts semantic versioning for the plugin contract, declared in two places:

  1. Framework version (shopdb/__init__.py): a single __contract_version__ constant. This is the version of the platform contract as defined in ADR-001. Bumped according to semver:
    • Major: breaking change to BasePlugin ABC, PluginMeta schema, or any model in the platform contract (Asset, AssetType, AssetStatus, AssetRelationship, Vendor, Location, BusinessUnit, Model, OperatingSystem).
    • Minor: additive change (new optional hook, new field on a contract model with default).
    • Patch: bug fix, no contract surface change.
  2. Plugin requirement (plugins/<name>/manifest.json): the existing core_version field, expressed as a semver range (e.g., ">=1.0.0,<2.0.0").

The plugin loader (shopdb/plugins/loader.py) checks core_version against __contract_version__ at load time. Mismatch in dev = re-raise (fail loud). Mismatch in prod = log error, mark plugin as incompatible, exclude from registration.

The __contract_version__ starts at 1.0.0 when ADR-001 is accepted and the Machine retirement migration is complete (whichever comes later). Until then, the framework is pre-1.0; plugins should declare core_version: ">=0.1.0,<1.0.0".

Consequences

Positive

  • Sister sites can pin a known-good framework version. They will not be silently broken when the framework is upgraded.
  • Plugin authors know what counts as a breaking change because the contract surface is enumerated in ADR-001.
  • The loader fails predictably: a mismatched plugin is reported, not silently disabled.

Negative / cost

  • Discipline required: every change to the contract surface must be classified (major / minor / patch). Adding a version-bump skill (or a check in code review) reduces the chance of mis-classification.
  • __contract_version__ becomes a coupling point. Forgetting to bump it after a breaking change means downstream plugins crash silently at runtime instead of failing at install.

Neutral

  • Existing plugins (plugins/printers/, etc.) ship as part of the framework, so their core_version is always the current __contract_version__. The discipline matters mostly for external / sister-site plugins.

Alternatives considered

  1. No versioning, just trust. Works for an in-tree-only world. Fails the moment a sister site ships its own plugin. Rejected.
  2. Calendar versioning (e.g., 2026.05.0). Easier to bump, harder to communicate breaking changes. Rejected; semver is the industry standard for library-like contracts.
  3. Per-hook versioning. Each hook has its own version. Too granular; plugins still couple to multiple hooks. Rejected.

Open questions

  • When does the framework declare 1.0.0? Tied to ADR-001 (Asset retirement of Machine) and the framework being deemed "ready for sister sites". Best-effort target: end of Phase 5 in the refactor plan.
  • Should core_version accept commercial-grade ranges (^1.0.0) or stick to PEP 440 / npm-style ranges? Recommend pip-style (>=,<) to match Python ecosystem.

References

  • shopdb/plugins/base.py (PluginMeta declaration)
  • shopdb/plugins/loader.py (where the version check belongs)
  • ADR-001 (defines what is in the contract)