Add provider deprecation support; change directory structure (#397)

* Add provider deprecation support; change directory structure

* fix a couple dangling imports

* move the meta_reference safety dir also

llama_stack/providers/inline/safety/meta_reference/safety.py

@@ -0,0 +1,112 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import Any, Dict, List
+
+from llama_stack.distribution.utils.model_utils import model_local_dir
+from llama_stack.apis.inference import *  # noqa: F403
+from llama_stack.apis.safety import *  # noqa: F403
+from llama_models.llama3.api.datatypes import *  # noqa: F403
+from llama_stack.distribution.datatypes import Api
+
+from llama_stack.providers.datatypes import ShieldsProtocolPrivate
+
+from .base import OnViolationAction, ShieldBase
+from .config import SafetyConfig
+from .llama_guard import LlamaGuardShield
+from .prompt_guard import InjectionShield, JailbreakShield, PromptGuardShield
+
+
+PROMPT_GUARD_MODEL = "Prompt-Guard-86M"
+
+
+class MetaReferenceSafetyImpl(Safety, ShieldsProtocolPrivate):
+    def __init__(self, config: SafetyConfig, deps) -> None:
+        self.config = config
+        self.inference_api = deps[Api.inference]
+
+        self.available_shields = []
+        if config.llama_guard_shield:
+            self.available_shields.append(ShieldType.llama_guard.value)
+        if config.enable_prompt_guard:
+            self.available_shields.append(ShieldType.prompt_guard.value)
+
+    async def initialize(self) -> None:
+        if self.config.enable_prompt_guard:
+            model_dir = model_local_dir(PROMPT_GUARD_MODEL)
+            _ = PromptGuardShield.instance(model_dir)
+
+    async def shutdown(self) -> None:
+        pass
+
+    async def register_shield(self, shield: ShieldDef) -> None:
+        raise ValueError("Registering dynamic shields is not supported")
+
+    async def list_shields(self) -> List[ShieldDef]:
+        return [
+            ShieldDef(
+                identifier=shield_type,
+                shield_type=shield_type,
+                params={},
+            )
+            for shield_type in self.available_shields
+        ]
+
+    async def run_shield(
+        self,
+        identifier: str,
+        messages: List[Message],
+        params: Dict[str, Any] = None,
+    ) -> RunShieldResponse:
+        shield_def = await self.shield_store.get_shield(identifier)
+        if not shield_def:
+            raise ValueError(f"Unknown shield {identifier}")
+
+        shield = self.get_shield_impl(shield_def)
+
+        messages = messages.copy()
+        # some shields like llama-guard require the first message to be a user message
+        # since this might be a tool call, first role might not be user
+        if len(messages) > 0 and messages[0].role != Role.user.value:
+            messages[0] = UserMessage(content=messages[0].content)
+
+        # TODO: we can refactor ShieldBase, etc. to be inline with the API types
+        res = await shield.run(messages)
+        violation = None
+        if res.is_violation and shield.on_violation_action != OnViolationAction.IGNORE:
+            violation = SafetyViolation(
+                violation_level=(
+                    ViolationLevel.ERROR
+                    if shield.on_violation_action == OnViolationAction.RAISE
+                    else ViolationLevel.WARN
+                ),
+                user_message=res.violation_return_message,
+                metadata={
+                    "violation_type": res.violation_type,
+                },
+            )
+
+        return RunShieldResponse(violation=violation)
+
+    def get_shield_impl(self, shield: ShieldDef) -> ShieldBase:
+        if shield.shield_type == ShieldType.llama_guard.value:
+            cfg = self.config.llama_guard_shield
+            return LlamaGuardShield(
+                model=cfg.model,
+                inference_api=self.inference_api,
+                excluded_categories=cfg.excluded_categories,
+            )
+        elif shield.shield_type == ShieldType.prompt_guard.value:
+            model_dir = model_local_dir(PROMPT_GUARD_MODEL)
+            subtype = shield.params.get("prompt_guard_type", "injection")
+            if subtype == "injection":
+                return InjectionShield.instance(model_dir)
+            elif subtype == "jailbreak":
+                return JailbreakShield.instance(model_dir)
+            else:
+                raise ValueError(f"Unknown prompt guard type: {subtype}")
+        else:
+            raise ValueError(f"Unknown shield type: {shield.shield_type}")