llama-stack-mirror/llama_stack/distribution/stack.py
Ashwin Bharambe 1463b79218
feat(registry): make the Stack query providers for model listing (#2862)
This flips #2823 and #2805 by making the Stack periodically query the
providers for models rather than the providers going behind the back and
calling "register" on to the registry themselves. This also adds support
for model listing for all other providers via `ModelRegistryHelper`.
Once this is done, we do not need to manually list or register models
via `run.yaml` and it will remove both noise and annoyance (setting
`INFERENCE_MODEL` environment variables, for example) from the new user
experience.

In addition, it adds a configuration variable `allowed_models` which can
be used to optionally restrict the set of models exposed from a
provider.
2025-07-24 10:39:53 -07:00

417 lines
16 KiB
Python

# 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.
import asyncio
import importlib.resources
import os
import re
import tempfile
from typing import Any
import yaml
from llama_stack.apis.agents import Agents
from llama_stack.apis.batch_inference import BatchInference
from llama_stack.apis.benchmarks import Benchmarks
from llama_stack.apis.datasetio import DatasetIO
from llama_stack.apis.datasets import Datasets
from llama_stack.apis.eval import Eval
from llama_stack.apis.files import Files
from llama_stack.apis.inference import Inference
from llama_stack.apis.inspect import Inspect
from llama_stack.apis.models import Models
from llama_stack.apis.post_training import PostTraining
from llama_stack.apis.providers import Providers
from llama_stack.apis.safety import Safety
from llama_stack.apis.scoring import Scoring
from llama_stack.apis.scoring_functions import ScoringFunctions
from llama_stack.apis.shields import Shields
from llama_stack.apis.synthetic_data_generation import SyntheticDataGeneration
from llama_stack.apis.telemetry import Telemetry
from llama_stack.apis.tools import RAGToolRuntime, ToolGroups, ToolRuntime
from llama_stack.apis.vector_dbs import VectorDBs
from llama_stack.apis.vector_io import VectorIO
from llama_stack.distribution.datatypes import Provider, StackRunConfig
from llama_stack.distribution.distribution import get_provider_registry
from llama_stack.distribution.inspect import DistributionInspectConfig, DistributionInspectImpl
from llama_stack.distribution.providers import ProviderImpl, ProviderImplConfig
from llama_stack.distribution.resolver import ProviderRegistry, resolve_impls
from llama_stack.distribution.routing_tables.common import CommonRoutingTableImpl
from llama_stack.distribution.store.registry import create_dist_registry
from llama_stack.distribution.utils.dynamic import instantiate_class_type
from llama_stack.log import get_logger
from llama_stack.providers.datatypes import Api
logger = get_logger(name=__name__, category="core")
class LlamaStack(
Providers,
VectorDBs,
Inference,
BatchInference,
Agents,
Safety,
SyntheticDataGeneration,
Datasets,
Telemetry,
PostTraining,
VectorIO,
Eval,
Benchmarks,
Scoring,
ScoringFunctions,
DatasetIO,
Models,
Shields,
Inspect,
ToolGroups,
ToolRuntime,
RAGToolRuntime,
Files,
):
pass
RESOURCES = [
("models", Api.models, "register_model", "list_models"),
("shields", Api.shields, "register_shield", "list_shields"),
("vector_dbs", Api.vector_dbs, "register_vector_db", "list_vector_dbs"),
("datasets", Api.datasets, "register_dataset", "list_datasets"),
(
"scoring_fns",
Api.scoring_functions,
"register_scoring_function",
"list_scoring_functions",
),
("benchmarks", Api.benchmarks, "register_benchmark", "list_benchmarks"),
("tool_groups", Api.tool_groups, "register_tool_group", "list_tool_groups"),
]
REGISTRY_REFRESH_INTERVAL_SECONDS = 300
async def register_resources(run_config: StackRunConfig, impls: dict[Api, Any]):
for rsrc, api, register_method, list_method in RESOURCES:
objects = getattr(run_config, rsrc)
if api not in impls:
continue
method = getattr(impls[api], register_method)
for obj in objects:
logger.debug(f"registering {rsrc.capitalize()} {obj} for provider {obj.provider_id}")
# Do not register models on disabled providers
if hasattr(obj, "provider_id") and obj.provider_id is not None and obj.provider_id == "__disabled__":
logger.debug(f"Skipping {rsrc.capitalize()} registration for disabled provider.")
continue
# In complex templates, like our starter template, we may have dynamic model ids
# given by environment variables. This allows those environment variables to have
# a default value of __disabled__ to skip registration of the model if not set.
if (
hasattr(obj, "provider_model_id")
and obj.provider_model_id is not None
and "__disabled__" in obj.provider_model_id
):
logger.debug(f"Skipping {rsrc.capitalize()} registration for disabled model.")
continue
if hasattr(obj, "shield_id") and obj.shield_id is not None and obj.shield_id == "__disabled__":
logger.debug(f"Skipping {rsrc.capitalize()} registration for disabled shield.")
continue
# we want to maintain the type information in arguments to method.
# instead of method(**obj.model_dump()), which may convert a typed attr to a dict,
# we use model_dump() to find all the attrs and then getattr to get the still typed value.
await method(**{k: getattr(obj, k) for k in obj.model_dump().keys()})
method = getattr(impls[api], list_method)
response = await method()
objects_to_process = response.data if hasattr(response, "data") else response
for obj in objects_to_process:
logger.debug(
f"{rsrc.capitalize()}: {obj.identifier} served by {obj.provider_id}",
)
class EnvVarError(Exception):
def __init__(self, var_name: str, path: str = ""):
self.var_name = var_name
self.path = path
super().__init__(
f"Environment variable '{var_name}' not set or empty {f'at {path}' if path else ''}. "
f"Use ${{env.{var_name}:=default_value}} to provide a default value, "
f"${{env.{var_name}:+value_if_set}} to make the field conditional, "
f"or ensure the environment variable is set."
)
def replace_env_vars(config: Any, path: str = "") -> Any:
if isinstance(config, dict):
result = {}
for k, v in config.items():
try:
result[k] = replace_env_vars(v, f"{path}.{k}" if path else k)
except EnvVarError as e:
raise EnvVarError(e.var_name, e.path) from None
return result
elif isinstance(config, list):
result = []
for i, v in enumerate(config):
try:
# Special handling for providers: first resolve the provider_id to check if provider
# is disabled so that we can skip config env variable expansion and avoid validation errors
if isinstance(v, dict) and "provider_id" in v:
try:
resolved_provider_id = replace_env_vars(v["provider_id"], f"{path}[{i}].provider_id")
if resolved_provider_id == "__disabled__":
logger.debug(
f"Skipping config env variable expansion for disabled provider: {v.get('provider_id', '')}"
)
# Create a copy with resolved provider_id but original config
disabled_provider = v.copy()
disabled_provider["provider_id"] = resolved_provider_id
continue
except EnvVarError:
# If we can't resolve the provider_id, continue with normal processing
pass
# Normal processing for non-disabled providers
result.append(replace_env_vars(v, f"{path}[{i}]"))
except EnvVarError as e:
raise EnvVarError(e.var_name, e.path) from None
return result
elif isinstance(config, str):
# Pattern supports bash-like syntax: := for default and :+ for conditional and a optional value
pattern = r"\${env\.([A-Z0-9_]+)(?::([=+])([^}]*))?}"
def get_env_var(match: re.Match):
env_var = match.group(1)
operator = match.group(2) # '=' for default, '+' for conditional
value_expr = match.group(3)
env_value = os.environ.get(env_var)
if operator == "=": # Default value syntax: ${env.FOO:=default}
# If the env is set like ${env.FOO:=default} then use the env value when set
if env_value:
value = env_value
else:
# If the env is not set, look for a default value
# value_expr returns empty string (not None) when not matched
# This means ${env.FOO:=} and it's accepted and returns empty string - just like bash
if value_expr == "":
return ""
else:
value = value_expr
elif operator == "+": # Conditional value syntax: ${env.FOO:+value_if_set}
# If the env is set like ${env.FOO:+value_if_set} then use the value_if_set
if env_value:
if value_expr:
value = value_expr
# This means ${env.FOO:+}
else:
# Just like bash, this doesn't care whether the env is set or not and applies
# the value, in this case the empty string
return ""
else:
# Just like bash, this doesn't care whether the env is set or not, since it's not set
# we return an empty string
value = ""
else: # No operator case: ${env.FOO}
if not env_value:
raise EnvVarError(env_var, path)
value = env_value
# expand "~" from the values
return os.path.expanduser(value)
try:
result = re.sub(pattern, get_env_var, config)
return _convert_string_to_proper_type(result)
except EnvVarError as e:
raise EnvVarError(e.var_name, e.path) from None
return config
def _convert_string_to_proper_type(value: str) -> Any:
# This might be tricky depending on what the config type is, if 'str | None' we are
# good, if 'str' we need to keep the empty string... 'str | None' is more common and
# providers config should be typed this way.
# TODO: we could try to load the config class and see if the config has a field with type 'str | None'
# and then convert the empty string to None or not
if value == "":
return None
lowered = value.lower()
if lowered == "true":
return True
elif lowered == "false":
return False
try:
return int(value)
except ValueError:
pass
try:
return float(value)
except ValueError:
pass
return value
def cast_image_name_to_string(config_dict: dict[str, Any]) -> dict[str, Any]:
"""Ensure that any value for a key 'image_name' in a config_dict is a string"""
if "image_name" in config_dict and config_dict["image_name"] is not None:
config_dict["image_name"] = str(config_dict["image_name"])
return config_dict
def validate_env_pair(env_pair: str) -> tuple[str, str]:
"""Validate and split an environment variable key-value pair."""
try:
key, value = env_pair.split("=", 1)
key = key.strip()
if not key:
raise ValueError(f"Empty key in environment variable pair: {env_pair}")
if not all(c.isalnum() or c == "_" for c in key):
raise ValueError(f"Key must contain only alphanumeric characters and underscores: {key}")
return key, value
except ValueError as e:
raise ValueError(
f"Invalid environment variable format '{env_pair}': {str(e)}. Expected format: KEY=value"
) from e
def add_internal_implementations(impls: dict[Api, Any], run_config: StackRunConfig) -> None:
"""Add internal implementations (inspect and providers) to the implementations dictionary.
Args:
impls: Dictionary of API implementations
run_config: Stack run configuration
"""
inspect_impl = DistributionInspectImpl(
DistributionInspectConfig(run_config=run_config),
deps=impls,
)
impls[Api.inspect] = inspect_impl
providers_impl = ProviderImpl(
ProviderImplConfig(run_config=run_config),
deps=impls,
)
impls[Api.providers] = providers_impl
# Produces a stack of providers for the given run config. Not all APIs may be
# asked for in the run config.
async def construct_stack(
run_config: StackRunConfig, provider_registry: ProviderRegistry | None = None
) -> dict[Api, Any]:
dist_registry, _ = await create_dist_registry(run_config.metadata_store, run_config.image_name)
policy = run_config.server.auth.access_policy if run_config.server.auth else []
impls = await resolve_impls(
run_config, provider_registry or get_provider_registry(run_config), dist_registry, policy
)
# Add internal implementations after all other providers are resolved
add_internal_implementations(impls, run_config)
await register_resources(run_config, impls)
task = asyncio.create_task(refresh_registry(impls))
def cb(task):
import traceback
if task.cancelled():
logger.error("Model refresh task cancelled")
elif task.exception():
logger.error(f"Model refresh task failed: {task.exception()}")
traceback.print_exception(task.exception())
else:
logger.debug("Model refresh task completed")
task.add_done_callback(cb)
return impls
async def refresh_registry(impls: dict[Api, Any]):
routing_tables = [v for v in impls.values() if isinstance(v, CommonRoutingTableImpl)]
while True:
for routing_table in routing_tables:
await routing_table.refresh()
await asyncio.sleep(REGISTRY_REFRESH_INTERVAL_SECONDS)
def get_stack_run_config_from_template(template: str) -> StackRunConfig:
template_path = importlib.resources.files("llama_stack") / f"templates/{template}/run.yaml"
with importlib.resources.as_file(template_path) as path:
if not path.exists():
raise ValueError(f"Template '{template}' not found at {template_path}")
run_config = yaml.safe_load(path.open())
return StackRunConfig(**replace_env_vars(run_config))
def run_config_from_adhoc_config_spec(
adhoc_config_spec: str, provider_registry: ProviderRegistry | None = None
) -> StackRunConfig:
"""
Create an adhoc distribution from a list of API providers.
The list should be of the form "api=provider", e.g. "inference=fireworks". If you have
multiple pairs, separate them with commas or semicolons, e.g. "inference=fireworks,safety=llama-guard,agents=meta-reference"
"""
api_providers = adhoc_config_spec.replace(";", ",").split(",")
provider_registry = provider_registry or get_provider_registry()
distro_dir = tempfile.mkdtemp()
provider_configs_by_api = {}
for api_provider in api_providers:
api_str, provider = api_provider.split("=")
api = Api(api_str)
providers_by_type = provider_registry[api]
provider_spec = providers_by_type.get(provider)
if not provider_spec:
provider_spec = providers_by_type.get(f"inline::{provider}")
if not provider_spec:
provider_spec = providers_by_type.get(f"remote::{provider}")
if not provider_spec:
raise ValueError(
f"Provider {provider} (or remote::{provider} or inline::{provider}) not found for API {api}"
)
# call method "sample_run_config" on the provider spec config class
provider_config_type = instantiate_class_type(provider_spec.config_class)
provider_config = replace_env_vars(provider_config_type.sample_run_config(__distro_dir__=distro_dir))
provider_configs_by_api[api_str] = [
Provider(
provider_id=provider,
provider_type=provider_spec.provider_type,
config=provider_config,
)
]
config = StackRunConfig(
image_name="distro-test",
apis=list(provider_configs_by_api.keys()),
providers=provider_configs_by_api,
)
return config