Plugins infrastructure

api/config/plugins.py

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+import copy
+import logging
+import os
+import subprocess
+import sys
+
+import persisting_theory
+from django.db.models import Q
+
+from rest_framework import serializers
+
+logger = logging.getLogger("plugins")
+
+
+class Startup(persisting_theory.Registry):
+    look_into = "persisting_theory"
+
+
+class Ready(persisting_theory.Registry):
+    look_into = "persisting_theory"
+
+
+startup = Startup()
+ready = Ready()
+
+_plugins = {}
+_filters = {}
+_hooks = {}
+
+
+def get_plugin_config(
+    name,
+    user=False,
+    source=False,
+    registry=_plugins,
+    conf={},
+    description=None,
+    version=None,
+    label=None,
+):
+    conf = {
+        "name": name,
+        "label": label or name,
+        "logger": logger,
+        "conf": conf,
+        "user": True if source else user,
+        "source": source,
+        "description": description,
+        "version": version,
+    }
+    registry[name] = conf
+    return conf
+
+
+def get_session():
+    from funkwhale_api.common import session
+
+    return session.get_session()
+
+
+def register_filter(name, plugin_config, registry=_filters):
+    def decorator(func):
+        handlers = registry.setdefault(name, [])
+
+        def inner(*args, **kwargs):
+            plugin_config["logger"].debug("Calling filter for %s", name)
+            rval = func(*args, **kwargs)
+            return rval
+
+        handlers.append((plugin_config["name"], inner))
+        return inner
+
+    return decorator
+
+
+def register_hook(name, plugin_config, registry=_hooks):
+    def decorator(func):
+        handlers = registry.setdefault(name, [])
+
+        def inner(*args, **kwargs):
+            plugin_config["logger"].debug("Calling hook for %s", name)
+            func(*args, **kwargs)
+
+        handlers.append((plugin_config["name"], inner))
+        return inner
+
+    return decorator
+
+
+class Skip(Exception):
+    pass
+
+
+def trigger_filter(name, value, enabled=False, **kwargs):
+    """
+    Call filters registered for "name" with the given
+    args and kwargs.
+
+    Return the value (that could be modified by handlers)
+    """
+    logger.debug("Calling handlers for filter %s", name)
+    registry = kwargs.pop("registry", _filters)
+    confs = kwargs.pop("confs", {})
+    for plugin_name, handler in registry.get(name, []):
+        if not enabled and confs.get(plugin_name, {}).get("enabled") is False:
+            continue
+        try:
+            value = handler(value, conf=confs.get(plugin_name, {}), **kwargs)
+        except Skip:
+            pass
+        except Exception as e:
+            logger.warn("Plugin %s errored during filter %s: %s", plugin_name, name, e)
+    return value
+
+
+def trigger_hook(name, enabled=False, **kwargs):
+    """
+    Call hooks registered for "name" with the given
+    args and kwargs.
+
+    Returns nothing
+    """
+    logger.debug("Calling handlers for hook %s", name)
+    registry = kwargs.pop("registry", _hooks)
+    confs = kwargs.pop("confs", {})
+    for plugin_name, handler in registry.get(name, []):
+        if not enabled and confs.get(plugin_name, {}).get("enabled") is False:
+            continue
+        try:
+            handler(conf=confs.get(plugin_name, {}).get("conf"), **kwargs)
+        except Skip:
+            pass
+        except Exception as e:
+            logger.warn("Plugin %s errored during hook %s: %s", plugin_name, name, e)
+
+
+def set_conf(name, conf, user=None, registry=_plugins):
+    from funkwhale_api.common import models
+
+    if not registry[name]["conf"] and not registry[name]["source"]:
+        return
+    conf_serializer = get_serializer_from_conf_template(
+        registry[name]["conf"], user=user, source=registry[name]["source"],
+    )(data=conf)
+    conf_serializer.is_valid(raise_exception=True)
+    if "library" in conf_serializer.validated_data:
+        conf_serializer.validated_data["library"] = str(
+            conf_serializer.validated_data["library"]
+        )
+    conf, _ = models.PluginConfiguration.objects.update_or_create(
+        user=user, code=name, defaults={"conf": conf_serializer.validated_data}
+    )
+
+
+def get_confs(user=None):
+    from funkwhale_api.common import models
+
+    qs = models.PluginConfiguration.objects.filter(code__in=list(_plugins.keys()))
+    if user:
+        qs = qs.filter(Q(user=None) | Q(user=user))
+    else:
+        qs = qs.filter(user=None)
+    confs = {
+        v["code"]: {"conf": v["conf"], "enabled": v["enabled"]}
+        for v in qs.values("code", "conf", "enabled")
+    }
+    for p, v in _plugins.items():
+        if p not in confs:
+            confs[p] = {"conf": None, "enabled": False}
+    return confs
+
+
+def get_conf(plugin, user=None):
+    return get_confs(user=user)[plugin]
+
+
+def enable_conf(code, value, user):
+    from funkwhale_api.common import models
+
+    models.PluginConfiguration.objects.update_or_create(
+        code=code, user=user, defaults={"enabled": value}
+    )
+
+
+class LibraryField(serializers.UUIDField):
+    def __init__(self, *args, **kwargs):
+        self.actor = kwargs.pop("actor")
+        super().__init__(*args, **kwargs)
+
+    def to_internal_value(self, v):
+        v = super().to_internal_value(v)
+        if not self.actor.libraries.filter(uuid=v).first():
+            raise serializers.ValidationError("Invalid library id")
+        return v
+
+
+def get_serializer_from_conf_template(conf, source=False, user=None):
+    conf = copy.deepcopy(conf)
+    validators = {f["name"]: f.pop("validator") for f in conf if "validator" in f}
+    mapping = {
+        "url": serializers.URLField,
+        "boolean": serializers.BooleanField,
+        "text": serializers.CharField,
+        "long_text": serializers.CharField,
+        "password": serializers.CharField,
+        "number": serializers.IntegerField,
+    }
+
+    for attr in ["label", "help"]:
+        for c in conf:
+            c.pop(attr, None)
+
+    class Serializer(serializers.Serializer):
+        def __init__(self, *args, **kwargs):
+            super().__init__(*args, **kwargs)
+            for field_conf in conf:
+                field_kwargs = copy.copy(field_conf)
+                name = field_kwargs.pop("name")
+                self.fields[name] = mapping[field_kwargs.pop("type")](**field_kwargs)
+            if source:
+                self.fields["library"] = LibraryField(actor=user.actor)
+
+    for vname, v in validators.items():
+        setattr(Serializer, "validate_{}".format(vname), v)
+    return Serializer
+
+
+def serialize_plugin(plugin_conf, confs):
+    return {
+        "name": plugin_conf["name"],
+        "label": plugin_conf["label"],
+        "description": plugin_conf.get("description") or None,
+        "user": plugin_conf.get("user", False),
+        "source": plugin_conf.get("source", False),
+        "conf": plugin_conf.get("conf", None),
+        "values": confs.get(plugin_conf["name"], {"conf"}).get("conf"),
+        "enabled": plugin_conf["name"] in confs
+        and confs[plugin_conf["name"]]["enabled"],
+    }
+
+
+def install_dependencies(deps):
+    if not deps:
+        return
+    logger.info("Installing plugins dependencies %s", deps)
+    pip_path = os.path.join(os.path.dirname(sys.executable), "pip")
+    subprocess.check_call([pip_path, "install"] + deps)
+
+
+def background_task(name):
+    from funkwhale_api.taskapp import celery
+
+    def decorator(func):
+        return celery.app.task(func, name=name)
+
+    return decorator
+
+
+# HOOKS
+LISTENING_CREATED = "listening_created"
+"""
+Called when a track is being listened
+"""
+SCAN = "scan"
+"""
+
+"""
+# FILTERS
+PLUGINS_DEPENDENCIES = "plugins_dependencies"
+"""
+Called with an empty list, use this filter to append pip dependencies
+to the list for installation.
+"""
+PLUGINS_APPS = "plugins_apps"
+"""
+Called with an empty list, use this filter to append apps to INSTALLED_APPS
+"""
+MIDDLEWARES_BEFORE = "middlewares_before"
+"""
+Called with an empty list, use this filter to prepend middlewares
+to MIDDLEWARE
+"""
+MIDDLEWARES_AFTER = "middlewares_after"
+"""
+Called with an empty list, use this filter to append middlewares
+to MIDDLEWARE
+"""
+URLS = "urls"
+"""
+Called with an empty list, use this filter to register new urls and views
+"""