Files
shopdb-flask/shopdb/plugins/__init__.py
cproudlock 1a6ac67cab
Some checks failed
CI / backend (push) Has been cancelled
CI / naming (push) Has been cancelled
CI / gates (push) Has been cancelled
CI / frontend (push) Has been cancelled
CI / lean-build (push) Has been cancelled
Say what a plugin settings tab can actually do, and catch a declaration that cannot work
Finding F12 of the architectural review, checked against the code and found
worse than reported: the dynamic component import cannot be rewritten by the
bundler, so the built file ships the unresolved path and a plugin tab answers
404 in every production build, staged or not. It works only under the dev
server. Nothing shipping is affected, because the one plugin that declares a
tab also registers the same page as an ordinary route, and that is the one
sites reach.

- The ADR draft now carries a "Constraints as implemented" section: only the
  model catalog hub registers plugin tabs, registration happens when that hub
  mounts so a tab is not deep-linkable and does not survive a refresh, and the
  build finding above with the bundler's own warning. The two ways out are
  stated as the open decision rather than taken.
- The hook's docstring reads as instructions to a plugin author, and its
  example no longer names a path that does not exist at build time.
- A route declared for a hub that cannot render it is dropped with an error
  naming the plugin, the hub and the hubs that do work, and the same is logged
  at startup. Enabling the plugin still succeeds: a tab nobody can reach is no
  reason to take a working backend offline.
- Tests hold the two halves together: no bundled plugin may declare a hub the
  frontend does not implement, and the list in the server must equal the hubs
  that really register routes, so the two cannot drift apart again.
2026-09-16 09:57:51 -04:00

730 lines
30 KiB
Python

"""Plugin manager - main entry point for plugin system."""
from pathlib import Path
from typing import Dict, List, Optional
from flask import Flask
import logging
import re
from .base import BasePlugin, PluginMeta, renderable_settings_routes
from .registry import PluginRegistry, PluginState
from .loader import PluginLoader
from .migrations import PluginMigrationManager
from ..exceptions import PluginError
logger = logging.getLogger(__name__)
__all__ = [
'PluginManager',
'BasePlugin',
'PluginMeta',
'PluginRegistry',
'PluginState',
'plugin_manager'
]
class PluginManager:
"""
Central manager for all plugin operations.
Usage:
plugin_manager = PluginManager()
plugin_manager.init_app(app, db)
# In CLI:
plugin_manager.install_plugin('printers')
"""
def __init__(self):
self.registry: Optional[PluginRegistry] = None
self.loader: Optional[PluginLoader] = None
self.migration_manager: Optional[PluginMigrationManager] = None
self.verifier = None
self._app: Optional[Flask] = None
self._db = None
# API prefixes already claimed by a registered plugin blueprint, to
# detect two plugins overlapping on the same /api/... namespace.
self._registered_prefixes: set = set()
def init_app(self, app: Flask, db) -> None:
"""Initialize plugin manager with Flask app."""
self._app = app
self._db = db
# Reset per-app so the prefix-uniqueness guard tracks only this app's
# registrations (the manager is a process-wide singleton; tests build
# multiple apps from it).
self._registered_prefixes = set()
# Setup paths
instance_path = Path(app.instance_path)
plugins_dir = Path(app.root_path).parent / 'plugins'
# Initialize components
self.registry = PluginRegistry(instance_path / 'plugins.json')
self.loader = PluginLoader(plugins_dir, self.registry)
self.migration_manager = PluginMigrationManager(
plugins_dir,
app.config.get('SQLALCHEMY_DATABASE_URI')
)
# One trust policy, shared by verify-at-load and verify-at-migrate.
from .verification import PluginVerifier
verifier = PluginVerifier(
plugins_dir,
require_signed=app.config.get('PLUGIN_REQUIRE_SIGNED', False),
trusted_key_paths=app.config.get('PLUGIN_TRUSTED_KEYS', []),
dev_trust_dirs=app.config.get('PLUGIN_DEV_TRUST_DIRS', []),
is_dev=bool(app.config.get('DEBUG') or app.config.get('TESTING')),
)
self.verifier = verifier
self.loader.verifier = verifier
self.migration_manager.verifier = verifier
# Install (or clear) the import guard that verifies every `plugins.*`
# import against a trusted signature. This is what covers the core
# request handlers that do `from plugins.<name>.models import ...`, which
# never pass through the loader (findings #1, #2).
from . import importguard
if verifier.require_signed:
importguard.install(plugins_dir, verifier)
else:
importguard.uninstall()
# Load enabled plugins
self._load_enabled_plugins()
# Store on app for access
app.extensions['plugin_manager'] = self
def _load_enabled_plugins(self) -> None:
"""Load and register all enabled plugins."""
plugins = self.loader.load_enabled_plugins(self._app, self._db)
for name, plugin in plugins.items():
self._register_plugin_components(plugin)
self._check_settings_routes(name, plugin)
def _check_settings_routes(self, name: str, plugin: BasePlugin) -> None:
"""Say at boot, once per plugin, if a declared settings tab is dead.
Only some settings hubs draw plugin tabs (see
SETTINGS_HUBS_WITH_PLUGIN_TABS). A route for any other hub is accepted
by the hook and returned by the API and then rendered by nobody, which
looks from every side like the plugin is at fault. The API drops such a
route; this makes the same finding at startup, so it is in the log of a
site that never opens the settings page."""
try:
renderable_settings_routes(name, plugin.get_settings_routes(),
logger)
except Exception:
logger.exception("get_settings_routes failed for %s", name)
def upgrade_all_plugins(self) -> Dict[str, str]:
"""Run pending Alembic migrations for every discovered plugin.
Returns {plugin_name: 'ok'|'no-migrations'|<error str>}. Skips
plugins with no migrations/ directory. Driven by the CLI
(`flask plugin upgrade-all`), which every deploy runs after
`flask db upgrade`. Each bundled plugin's chain begins with a
stamp-only anchor (the core chain already built its tables); later
per-plugin migrations extend that chain. See ADR-008. Idempotent.
"""
results: Dict[str, str] = {}
# Settings declared by a later plugin version reach an already-installed
# site here. on_install/on_enable fire only on a state transition, so an
# upgrade is the only moment left to seed them. Runs even with no
# migration manager - it is independent of the Alembic chains.
self.sync_all_plugin_settings()
# Permissions need the same treatment for the same reason. A permission
# added in a later plugin version would otherwise exist only after a
# manual `flask seed permissions`, and until someone ran it the route
# guarding on that name would refuse every caller - including admins on
# sites that gate by permission rather than role. Deploys run
# upgrade-all, so this is the moment the new name has to appear.
self.sync_all_plugin_permissions()
if not self.migration_manager:
return results
# Only ADOPTED plugins (those in the registry) get migrated. A plugin
# folder that merely sits on disk unadopted must not have its DDL run as
# a side effect of a deploy - migrations execute with full DB rights, so
# "on disk" is not "trusted to run". (The old code probed a
# list_installed() method the registry never had, so it always fell
# through to discover_plugins() and migrated every folder.)
plugin_names = list(self.registry.get_all().keys())
for name in plugin_names:
if not self.migration_manager.has_pending_migrations(name):
results[name] = 'no-migrations'
continue
try:
ok = self.migration_manager.run_plugin_migrations(name)
results[name] = 'ok' if ok else 'failed'
except Exception as ex:
results[name] = f'error: {ex}'
return results
def sync_all_plugin_settings(self) -> int:
"""Seed every enabled plugin's declared settings. Idempotent.
Returns the number of plugins whose settings were touched. Best-effort
per plugin: one bad plugin must not abort a deploy's upgrade pass.
"""
touched = 0
for name in list(self.registry.get_all().keys()):
if not self.registry.is_enabled(name):
continue
try:
plugin = self.loader.load_plugin(name, self._app, self._db)
except Exception:
logger.exception("Could not load %s to sync its settings", name)
continue
if plugin and self._seed_plugin_settings(plugin):
touched += 1
return touched
def sync_all_plugin_permissions(self) -> int:
"""Seed every enabled plugin's declared permissions, then relink scopes.
Returns the number of plugins whose permissions were seeded. Best-effort
per plugin: one bad plugin must not abort a deploy's upgrade pass.
The scope relink is the load-bearing half. Creating the Permission row
only makes the name exist; the prebuilt scopes derive their grants from
the catalog, so a permission seeded without a following
Role.seedscopes() belongs to nobody but admin. The symptom is a plugin
that installs cleanly and whose UI is invisible to every non-admin until
someone re-runs the seed by hand. Ordering matters for the same reason
it does in `flask seed permissions`: seedscopes only links rows that
already exist, so it runs last.
"""
touched = 0
for name in list(self.registry.get_all().keys()):
if not self.registry.is_enabled(name):
continue
try:
plugin = self.loader.load_plugin(name, self._app, self._db)
except Exception:
logger.exception(
"Could not load %s to sync its permissions", name)
continue
if plugin:
self._seed_plugin_permissions(plugin)
touched += 1
# Additive: this can hand a scope a newly declared permission, never
# take one away, so a site's deliberate role edits survive the deploy.
from shopdb.core.models import Role
try:
with self._app.app_context():
result = Role.seedscopes()
self._db.session.commit()
granted = sum((result or {}).get('granted', {}).values())
if granted:
logger.info(
"Linked %d new scope grant(s) after plugin upgrade",
granted)
except Exception:
logger.exception("Could not relink prebuilt scopes after upgrade")
return touched
def get_declared_plugin_settings(self) -> Dict[str, dict]:
"""Return {key: declared entry} across all loaded plugins.
The settings API uses this to file a first-time write under the owning
plugin's category instead of a placeholder, and to decide which keys an
unauthenticated caller may read.
"""
declared: Dict[str, dict] = {}
for name, plugin in self.loader.get_all_loaded().items():
try:
entries = plugin.get_settings_defaults() or []
except Exception:
logger.exception("get_settings_defaults failed for %s", name)
continue
for entry in entries:
key = entry.get('key')
if key:
declared[key] = entry
return declared
def get_public_setting_keys(self) -> set:
"""Setting keys plugins declare readable without authentication."""
return {key for key, entry in self.get_declared_plugin_settings().items()
if entry.get('public')}
def _register_plugin_components(self, plugin: BasePlugin) -> None:
"""Register plugin's blueprint, models, CLI commands, etc."""
# Register blueprint
blueprint = plugin.get_blueprint()
if blueprint:
prefix = plugin.meta.api_prefix
# Guard against two plugins claiming the same API prefix; Flask only
# rejects duplicate blueprint names, not overlapping url_prefixes, so
# an overlap would silently shadow routes.
if prefix in self._registered_prefixes:
raise ValueError(
f"Plugin {plugin.meta.name} api_prefix '{prefix}' is already "
f"claimed by another blueprint"
)
self._app.register_blueprint(blueprint, url_prefix=prefix)
self._registered_prefixes.add(prefix)
logger.debug(f"Registered blueprint: {prefix}")
# Register CLI commands
for cmd in plugin.get_cli_commands():
self._app.cli.add_command(cmd)
def discover_available(self) -> List[Dict]:
"""
Get list of all available plugins (installed or not).
Returns list of plugin info dicts.
"""
available = []
for name in self.loader.discover_plugins():
# Under enforcement load_plugin_class refuses an unverified plugin
# (it will not import it). Skip such a plugin from the listing
# instead of failing the whole call.
try:
plugin_class = self.loader.load_plugin_class(name)
except PluginError as e:
logger.warning(f"Skipping plugin {name} in listing: {e}")
continue
if plugin_class:
try:
temp = plugin_class()
meta = temp.meta
state = self.registry.get(name)
try:
config_schema = temp.get_config_schema()
except Exception:
config_schema = []
try:
provisioning_note = temp.get_provisioning_note()
except Exception:
provisioning_note = None
manifest = self.loader.load_manifest(name)
available.append({
'name': meta.name,
# Human label for UIs. Manifest display_name wins; else
# title-case the machine name (right for most, e.g.
# "computers" -> "Computers").
'displayname': (manifest.get('display_name')
or meta.name.replace('_', ' ').title()),
'version': meta.version,
'description': meta.description,
'author': meta.author,
'dependencies': meta.dependencies,
'installed': state is not None,
'enabled': state.enabled if state else False,
'installedat': state.installed_at if state else None,
'config_schema': config_schema,
'provisioning_note': provisioning_note,
'default_enabled': manifest.get('default_enabled', True),
})
except Exception as e:
logger.warning(f"Error inspecting plugin {name}: {e}")
return available
def install_plugin(self, name: str, run_migrations: bool = True) -> bool:
"""
Install a plugin.
Steps:
1. Verify plugin exists
2. Check dependencies
3. Run database migrations
4. Register in registry
5. Call plugin's on_install hook
"""
# Check if already installed
if self.registry.is_installed(name):
logger.warning(f"Plugin {name} is already installed")
return False
# Read metadata from the manifest (single source of truth) instead of
# instantiating the plugin class just to inspect deps/version.
manifest = self.loader.load_manifest(name)
if not manifest:
logger.error(f"Plugin {name} not found")
return False
manifest_version = manifest.get('version')
# Check dependencies
for dep in manifest.get('dependencies', []):
if not self.registry.is_installed(dep):
logger.error(
f"Plugin {name} requires {dep} to be installed first"
)
return False
# Run migrations
if run_migrations:
success = self.migration_manager.run_plugin_migrations(name)
if not success:
logger.error(f"Failed to run migrations for {name}")
return False
# Register plugin
# Plugins that provision extra tables install disabled until a site
# opts in (manifest default_enabled=false).
self.registry.register(name, manifest_version,
enabled=manifest.get('default_enabled', True))
# Load the plugin
plugin = self.loader.load_plugin(name, self._app, self._db)
if plugin:
self._register_plugin_components(plugin)
self._seed_plugin_permissions(plugin)
self._seed_plugin_settings(plugin)
plugin.on_install(self._app)
logger.info(f"Installed plugin: {name} v{manifest_version}")
return True
def _seed_plugin_permissions(self, plugin: BasePlugin) -> None:
"""Idempotently create Permission rows for a plugin's declared perms.
Runs at install and enable so a fresh plugin's RBAC permissions exist
without a separate `flask seed permissions` pass. Best-effort: a plugin
that raises must not abort the lifecycle."""
try:
entries = plugin.get_permissions() or []
except Exception:
logger.exception(
"get_permissions failed for %s", plugin.meta.name)
return
if not entries:
return
from shopdb.core.models import Permission
with self._app.app_context():
created = Permission.seed_entries(entries)
if created:
self._db.session.commit()
logger.info(
"Seeded %d permission(s) for plugin %s",
created, plugin.meta.name)
def _seed_plugin_settings(self, plugin: BasePlugin) -> bool:
"""Idempotently create Setting rows for a plugin's declared settings.
Runs at install, at enable, and on `flask plugin upgrade-all`. Existing
values are never overwritten - only missing rows are created, and a row
whose category does not match the declaration is re-homed. That repair
matters: before a key was declared, the first save created it under the
settings API's placeholder category, where the owning plugin's settings
page (which filters by category) could not see it again, so the value
looked like it never saved.
Returns True if anything was created or repaired. Best-effort: a plugin
that raises must not abort the lifecycle.
"""
try:
entries = plugin.get_settings_defaults() or []
except Exception:
logger.exception(
"get_settings_defaults failed for %s", plugin.meta.name)
return False
if not entries:
return False
from shopdb.core.models import Setting
created = 0
repaired = 0
with self._app.app_context():
for entry in entries:
key = entry.get('key')
if not key:
continue
setting = Setting.query.filter_by(key=key).first()
if setting is None:
self._db.session.add(Setting(
key=key,
value=entry.get('value', ''),
valuetype=entry.get('valuetype', 'string'),
category=entry.get('category', 'plugin'),
description=entry.get('description'),
))
created += 1
continue
category = entry.get('category')
if category and setting.category != category:
setting.category = category
repaired += 1
if created or repaired:
self._db.session.commit()
logger.info(
"Plugin %s settings: %d created, %d re-homed",
plugin.meta.name, created, repaired)
return bool(created or repaired)
def _is_core_tier(self, name: str) -> bool:
"""True when the plugin's manifest marks it tier=core (mandatory).
A core-tier plugin refuses uninstall/disable so a site cannot remove a
plugin its deployment depends on. No plugin ships tier=core today; the
guard makes that a manifest edit, not a code change (ADR-013).
"""
try:
return self.loader.load_manifest(name).get('tier') == 'core'
except PluginError:
return False
def _installed_dependents(self, name: str,
enabled_only: bool = False) -> List[str]:
"""Installed plugins that declare `name` as a hard dependency.
Reads each dependency list from the manifest on DISK, not from a loaded
plugin instance, so a dependent that is installed-but-not-loaded (e.g.
disabled, or failed to load) is still counted. enabled_only restricts to
currently-enabled dependents (what matters when disabling, since a
disabled dependent is not running).
"""
dependents = []
for other_name, state in self.registry.get_all().items():
if other_name == name:
continue
if enabled_only and not state.enabled:
continue
try:
manifest = self.loader.load_manifest(other_name)
except PluginError:
continue
if name in manifest.get('dependencies', []):
dependents.append(other_name)
return dependents
def uninstall_plugin(self, name: str, remove_data: bool = False) -> bool:
"""
Uninstall a plugin.
Args:
name: Plugin name
remove_data: If True, run downgrade migrations to remove tables
"""
if not self.registry.is_installed(name):
logger.warning(f"Plugin {name} is not installed")
return False
if self._is_core_tier(name):
logger.error(f"Cannot uninstall {name}: it is a core-tier plugin")
return False
# Refuse if any INSTALLED plugin (enabled or not) depends on this one.
dependents = self._installed_dependents(name)
if dependents:
logger.error(
f"Cannot uninstall {name}: {', '.join(dependents)} depend(s) on it"
)
return False
# Get plugin instance
plugin = self.loader.get_loaded_plugin(name)
# Call on_uninstall hook
if plugin:
plugin.on_uninstall(self._app)
# Optionally remove data
if remove_data:
self.migration_manager.downgrade_plugin(name)
# Unregister
self.registry.unregister(name)
logger.info(f"Uninstalled plugin: {name}")
return True
def enable_plugin(self, name: str) -> bool:
"""Enable a disabled plugin. Auto-installs if available but not installed."""
# Security: Validate plugin name to prevent path traversal
# Only allow alphanumeric, underscore, and hyphen (matches existing plugins)
if not re.match(r'^[a-zA-Z0-9_-]+$', name):
logger.error(f"Invalid plugin name format: {name}")
return False
# Reject reserved names that could be used for directory traversal
if name in ('.', '..', ''):
logger.error(f"Invalid plugin name: {name}")
return False
# Auto-install if available but not installed (UX: enabling should just work)
if not self.registry.is_installed(name):
logger.info(f"Plugin {name} not installed, installing first")
if not self.install_plugin(name):
logger.error(f"Failed to install plugin {name}")
return False
if self.registry.is_enabled(name):
logger.info(f"Plugin {name} is already enabled")
return True
# Check dependencies are enabled. Read deps from the manifest, not by
# instantiating the plugin class (manifest is the single source of
# truth; instantiating fires __init__ side effects unnecessarily).
manifest = self.loader.load_manifest(name)
for dep in manifest.get('dependencies', []):
if not self.registry.is_enabled(dep):
logger.error(f"Cannot enable {name}: {dep} is not enabled")
return False
self.registry.enable(name)
# Surface (do not auto-apply) a plugin chain that is ahead of the DB, so
# an operator enabling a plugin knows to run `flask plugin upgrade-all`.
try:
if self.migration_manager and \
self.migration_manager.has_unapplied_migrations(name):
logger.warning(
f"Plugin {name} has unapplied migrations; "
f"run 'flask plugin upgrade-all'"
)
except Exception:
logger.debug(f"Could not check migration state for {name}")
# Fire the on_enable hook best-effort. Do NOT register the blueprint
# here: Flask forbids register_blueprint after the first request, so
# routes/nav for a re-enabled plugin take effect on the next restart
# (symmetric with disable).
try:
plugin = self.loader.load_plugin(name, self._app, self._db)
if plugin:
self._seed_plugin_permissions(plugin)
self._seed_plugin_settings(plugin)
plugin.on_enable(self._app)
except Exception:
logger.exception(f"on_enable hook failed for plugin {name}")
logger.info(f"Enabled plugin: {name}")
return True
def disable_plugin(self, name: str) -> bool:
"""Disable an enabled plugin."""
if not self.registry.is_enabled(name):
logger.info(f"Plugin {name} is already disabled")
return True
if self._is_core_tier(name):
logger.error(f"Cannot disable {name}: it is a core-tier plugin")
return False
# Refuse if any ENABLED plugin depends on this one (a disabled dependent
# is not running, so it does not block). Manifests read from disk.
dependents = self._installed_dependents(name, enabled_only=True)
if dependents:
logger.error(
f"Cannot disable {name}: {', '.join(dependents)} depend(s) on it"
)
return False
plugin = self.loader.get_loaded_plugin(name)
if plugin:
plugin.on_disable(self._app)
self.registry.disable(name)
logger.info(f"Disabled plugin: {name}")
return True
def _dependency_closure(self, names: List[str]) -> List[str]:
"""Chosen plugins plus their hard-dependency closure, dependencies first.
Post-order DFS over manifest `dependencies`, so the returned order is
safe to install/enable top to bottom (a dependency always precedes the
plugin that needs it). Deduplicated.
"""
closure: List[str] = []
seen = set()
def add(name):
if name in seen:
return
seen.add(name)
try:
deps = self.loader.load_manifest(name).get('dependencies', [])
except PluginError:
deps = []
for dep in deps:
add(dep)
closure.append(name)
for name in names:
add(name)
return closure
def apply_profile(self, plugins: List[str],
locked: Optional[List[str]] = None) -> Dict[str, List[str]]:
"""Install AND enable exactly the chosen plugins plus their dependency
closure, in dependency order.
Declarative replacement for the hand-ordered install/enable sequences in
the deploy runbooks (which could enable a plugin that was never
installed). Idempotent: already-installed/enabled plugins are left as-is.
This does NOT remove anything absent from the list - removal stays an
explicit, separate operation. `locked` is accepted for forward
compatibility (a future guard against removing a site-mandated plugin)
and is currently informational.
Raises PluginError if the profile names a plugin (or pulls in a
dependency) that does not exist on disk. Returns
{installed: [...], enabled: [...], already: [...]}.
"""
available = set(self.loader.discover_plugins())
unknown = [p for p in plugins if p not in available]
if unknown:
raise PluginError(
f"Profile names unknown plugins: {', '.join(sorted(unknown))}")
order = self._dependency_closure(plugins)
missing_deps = [p for p in order if p not in available]
if missing_deps:
raise PluginError(
f"Missing dependency plugins: {', '.join(sorted(missing_deps))}")
result: Dict[str, List[str]] = {
'installed': [], 'enabled': [], 'already': []}
for name in order:
changed = False
if not self.registry.is_installed(name):
if self.install_plugin(name):
result['installed'].append(name)
changed = True
if not self.registry.is_enabled(name):
if self.enable_plugin(name):
result['enabled'].append(name)
changed = True
if not changed:
result['already'].append(name)
return result
def get_plugin(self, name: str) -> Optional[BasePlugin]:
"""Get a loaded plugin instance."""
return self.loader.get_loaded_plugin(name)
def get_all_plugins(self) -> Dict[str, BasePlugin]:
"""Get all loaded plugins."""
return self.loader.get_all_loaded()
def get_service(self, name: str):
"""Resolve a service exposed by an enabled plugin via get_services().
Consumer for the BasePlugin.get_services hook: searches enabled plugins
for one that registers `name` and returns the registered value (a service
class or factory). Returns None if no enabled plugin provides it. This is
how one plugin obtains another's service (e.g. the Zabbix service).
"""
for plugin_name, plugin in self.get_all_plugins().items():
if not self.registry.is_enabled(plugin_name):
continue
try:
services = plugin.get_services() or {}
except Exception:
continue
if name in services:
return services[name]
return None
# Global plugin manager instance
plugin_manager = PluginManager()