plugin-contract-guard

# Plugin & Extension Contract Guard The "plugin system" spans four surfaces that must stay consistent: | Surface | Location | |---|---| | Manifests & registry | `crates/targets/src/{manifest,plugin}.rs` | | Install/enable planning (control plane) | `crates/targets/src/control_plane.rs` | | Extension schemas | `crates/extension-schema/src/lib.rs`, `crates/targets/src/catalog/extension.rs` | | Admin API contract | `rustfs/src/admin/plugin_contract.rs`, `handlers/{plugins_catalog,plugins_instances,extensions,target_descriptor}.rs` | ## Hard invariants (verify before merging) 1. **Secrets have one source of truth.** Secret config keys are declared only in the plugin manifest (`TargetPluginManifest.secret_fields`, `crates/targets/src/manifest.rs`) and flow to admin via `AdminTargetSpec.secret_fields`. Never add a hand-maintained per-service secret table in a handler; if redaction misses a field, fix the manifest. 2. **Redaction must round-trip.** Instance GET responses replace secret values with `***redacted***` (`REDACTED_SECRET_VALUE` in `plugins_instances.rs`). Instance PUT restores the stored secret when it receives that placeholder back (`restore_redacted_secret_values`). Any new read or write path for target config must keep both halves: redact on the way out, restore the placeholder on the way in. The placeholder literal must never be persisted. 3. **Fixtures never reach production responses.** `example_external_webhook_plugin()` (`crates/targets/src/catalog/mod.rs`) is a test/demo fixture for control-plane planning tests. Production catalog/extension handlers must not include it; regression tests (`plugin_catalog_never_exposes_example_or_external_fixtures`, `extension_catalog_never_exposes_example_or_external_fixtures`) enforce it. 4. **External plugin flow is planning-only and deny-by-default.** `plan_external_target_plugin_action` returns decisions, it executes nothing. `TargetPluginExternalFlowGate::default()` is fully closed and `TargetPluginInstallPolicy::default().allowed_download_hosts` is empty — keep it that way; tests opt in via explicit policies. Install validation requires https, an allowlisted host, a full 64-hex-char sha256 digest, signature and provenance URIs, and an artifact matching the host `target_triple`. 5. **Custom target types must not collide.** Unknown target types get an interned unique `custom:<type>` plugin id (`custom_plugin_id` in `manifest.rs`). Custom plugins with secrets must register via `TargetPluginDescriptor::with_manifest` and declare `secret_fields`; `::new` derives a manifest with no secrets. ## Changing the admin JSON contract - Shapes are locked twice in `plugin_contract.rs` tests: insta snapshots (`rustfs/src/admin/snapshots/`) plus literal `json!` assertions. Update both deliberately; a shape change is a console-facing API change. - Field naming is `snake_case`, except discovery blocks (`runtimeCapabilities`, `clusterSnapshot`, `extensionsCatalog`) which are camelCase **by cross-endpoint convention** (same shape in `system.rs`, `console.rs`, `pools.rs`). Do not "fix" that inconsistency locally. - Contract types deliberately duplicate `rustfs_targets` types (anti-corruption layer). Add a `From` impl; do not serialize internal types directly. ## Handler conventions - Every new admin plugin/extension route needs authorization at the top of `call` and an `include_str!` guard test asserting it (repo-wide pattern — see `plugin_instance_handlers_require_admin_authorization_contract`). - Reads use `GetBucketTargetAction` (instances) or `ServerInfoAdminAction` (catalogs); writes use `SetBucketTargetAction`. - Refresh persisted module switches once per request (`refresh_persisted_module_switches`), then evaluate the sync `module_disabled_block_reason` per domain — do not re-read the store per domain or per instance. ## Generic bounds Event-payload generics use the `PluginEvent` blanket trait (`crates/targets/src/plugin.rs`). Do not respell `Send + Sync + 'static + Clone + Serialize + DeserializeOwned`.