Merge branch 'refs/heads/main' into preprocessors

# Conflicts:
#	llama_stack/distribution/routers/routers.py
#	llama_stack/templates/ollama/build.yaml
#	llama_stack/templates/ollama/run-with-safety.yaml
#	llama_stack/templates/ollama/run.yaml
#	llama_stack/templates/remote-vllm/build.yaml
#	llama_stack/templates/remote-vllm/run-with-safety.yaml
#	llama_stack/templates/remote-vllm/run.yaml
#	llama_stack/templates/together/build.yaml
#	llama_stack/templates/together/run-with-safety.yaml
#	llama_stack/templates/together/run.yaml

llama_stack/distribution/stack.py

@@ -5,14 +5,15 @@
 # the root directory of this source tree.
 
 import importlib.resources
-import logging
 import os
 import re
+import tempfile
 from typing import Any, Dict, Optional
 
 import yaml
 from termcolor import colored
 
+from llama_stack import logcat
 from llama_stack.apis.agents import Agents
 from llama_stack.apis.batch_inference import BatchInference
 from llama_stack.apis.benchmarks import Benchmarks
@@ -35,14 +36,13 @@ 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 StackRunConfig
+from llama_stack.distribution.datatypes import Provider, StackRunConfig
 from llama_stack.distribution.distribution import get_provider_registry
 from llama_stack.distribution.resolver import ProviderRegistry, resolve_impls
 from llama_stack.distribution.store.registry import create_dist_registry
+from llama_stack.distribution.utils.dynamic import instantiate_class_type
 from llama_stack.providers.datatypes import Api
 
-log = logging.getLogger(__name__)
-
 
 class LlamaStack(
     VectorDBs,
@@ -106,12 +106,11 @@ async def register_resources(run_config: StackRunConfig, impls: Dict[Api, Any]):
         objects_to_process = response.data if hasattr(response, "data") else response
 
         for obj in objects_to_process:
-            log.info(
+            logcat.debug(
+                "core",
                 f"{rsrc.capitalize()}: {colored(obj.identifier, 'white', attrs=['bold'])} served by {colored(obj.provider_id, 'white', attrs=['bold'])}",
             )
 
-    log.info("")
-
 
 class EnvVarError(Exception):
     def __init__(self, var_name: str, path: str = ""):
@@ -160,18 +159,34 @@ def replace_env_vars(config: Any, path: str = "") -> Any:
         return result
 
     elif isinstance(config, str):
-        pattern = r"\${env\.([A-Z0-9_]+)(?::([^}]*))?}"
+        # Updated pattern to support both default values (:) and conditional values (+)
+        pattern = r"\${env\.([A-Z0-9_]+)(?:([:\+])([^}]*))?}"
 
         def get_env_var(match):
             env_var = match.group(1)
-            default_val = match.group(2)
+            operator = match.group(2)  # ':' for default, '+' for conditional
+            value_expr = match.group(3)
 
-            value = os.environ.get(env_var)
-            if not value:
-                if default_val is None:
-                    raise EnvVarError(env_var, path)
+            env_value = os.environ.get(env_var)
+
+            if operator == ":":  # Default value syntax: ${env.FOO:default}
+                if not env_value:
+                    if value_expr is None:
+                        raise EnvVarError(env_var, path)
+                    else:
+                        value = value_expr
                 else:
-                    value = default_val
+                    value = env_value
+            elif operator == "+":  # Conditional value syntax: ${env.FOO+value_if_set}
+                if env_value:
+                    value = value_expr
+                else:
+                    # If env var is not set, return empty string for the conditional case
+                    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)
@@ -220,3 +235,53 @@ def get_stack_run_config_from_template(template: str) -> StackRunConfig:
         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: Optional[ProviderRegistry] = 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