chore(rename): move llama_stack.distribution to llama_stack.core (#2975)

We would like to rename the term `template` to `distribution`. To
prepare for that, this is a precursor.

cc @leseb

llama_stack/core/build.py

@@ -0,0 +1,177 @@
+# 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 importlib.resources
+import logging
+import sys
+from pathlib import Path
+
+from pydantic import BaseModel
+from termcolor import cprint
+
+from llama_stack.core.datatypes import BuildConfig
+from llama_stack.core.distribution import get_provider_registry
+from llama_stack.core.external import load_external_apis
+from llama_stack.core.utils.exec import run_command
+from llama_stack.core.utils.image_types import LlamaStackImageType
+from llama_stack.providers.datatypes import Api
+from llama_stack.templates.template import DistributionTemplate
+
+log = logging.getLogger(__name__)
+
+# These are the dependencies needed by the distribution server.
+# `llama-stack` is automatically installed by the installation script.
+SERVER_DEPENDENCIES = [
+    "aiosqlite",
+    "fastapi",
+    "fire",
+    "httpx",
+    "uvicorn",
+    "opentelemetry-sdk",
+    "opentelemetry-exporter-otlp-proto-http",
+]
+
+
+class ApiInput(BaseModel):
+    api: Api
+    provider: str
+
+
+def get_provider_dependencies(
+    config: BuildConfig | DistributionTemplate,
+) -> tuple[list[str], list[str], list[str]]:
+    """Get normal and special dependencies from provider configuration."""
+    if isinstance(config, DistributionTemplate):
+        config = config.build_config()
+
+    providers = config.distribution_spec.providers
+    additional_pip_packages = config.additional_pip_packages
+
+    deps = []
+    external_provider_deps = []
+    registry = get_provider_registry(config)
+    for api_str, provider_or_providers in providers.items():
+        providers_for_api = registry[Api(api_str)]
+
+        providers = provider_or_providers if isinstance(provider_or_providers, list) else [provider_or_providers]
+
+        for provider in providers:
+            # Providers from BuildConfig and RunConfig are subtly different - not great
+            provider_type = provider if isinstance(provider, str) else provider.provider_type
+
+            if provider_type not in providers_for_api:
+                raise ValueError(f"Provider `{provider}` is not available for API `{api_str}`")
+
+            provider_spec = providers_for_api[provider_type]
+            if hasattr(provider_spec, "is_external") and provider_spec.is_external:
+                # this ensures we install the top level module for our external providers
+                if provider_spec.module:
+                    if isinstance(provider_spec.module, str):
+                        external_provider_deps.append(provider_spec.module)
+                    else:
+                        external_provider_deps.extend(provider_spec.module)
+            if hasattr(provider_spec, "pip_packages"):
+                deps.extend(provider_spec.pip_packages)
+            if hasattr(provider_spec, "container_image") and provider_spec.container_image:
+                raise ValueError("A stack's dependencies cannot have a container image")
+
+    normal_deps = []
+    special_deps = []
+    for package in deps:
+        if "--no-deps" in package or "--index-url" in package:
+            special_deps.append(package)
+        else:
+            normal_deps.append(package)
+
+    normal_deps.extend(additional_pip_packages or [])
+
+    return list(set(normal_deps)), list(set(special_deps)), list(set(external_provider_deps))
+
+
+def print_pip_install_help(config: BuildConfig):
+    normal_deps, special_deps = get_provider_dependencies(config)
+
+    cprint(
+        f"Please install needed dependencies using the following commands:\n\nuv pip install {' '.join(normal_deps)}",
+        color="yellow",
+        file=sys.stderr,
+    )
+    for special_dep in special_deps:
+        cprint(f"uv pip install {special_dep}", color="yellow", file=sys.stderr)
+    print()
+
+
+def build_image(
+    build_config: BuildConfig,
+    build_file_path: Path,
+    image_name: str,
+    template_or_config: str,
+    run_config: str | None = None,
+):
+    container_base = build_config.distribution_spec.container_image or "python:3.12-slim"
+
+    normal_deps, special_deps, external_provider_deps = get_provider_dependencies(build_config)
+    normal_deps += SERVER_DEPENDENCIES
+    if build_config.external_apis_dir:
+        external_apis = load_external_apis(build_config)
+        if external_apis:
+            for _, api_spec in external_apis.items():
+                normal_deps.extend(api_spec.pip_packages)
+
+    if build_config.image_type == LlamaStackImageType.CONTAINER.value:
+        script = str(importlib.resources.files("llama_stack") / "core/build_container.sh")
+        args = [
+            script,
+            "--template-or-config",
+            template_or_config,
+            "--image-name",
+            image_name,
+            "--container-base",
+            container_base,
+            "--normal-deps",
+            " ".join(normal_deps),
+        ]
+        # When building from a config file (not a template), include the run config path in the
+        # build arguments
+        if run_config is not None:
+            args.extend(["--run-config", run_config])
+    elif build_config.image_type == LlamaStackImageType.CONDA.value:
+        script = str(importlib.resources.files("llama_stack") / "core/build_conda_env.sh")
+        args = [
+            script,
+            "--env-name",
+            str(image_name),
+            "--build-file-path",
+            str(build_file_path),
+            "--normal-deps",
+            " ".join(normal_deps),
+        ]
+    elif build_config.image_type == LlamaStackImageType.VENV.value:
+        script = str(importlib.resources.files("llama_stack") / "core/build_venv.sh")
+        args = [
+            script,
+            "--env-name",
+            str(image_name),
+            "--normal-deps",
+            " ".join(normal_deps),
+        ]
+
+    # Always pass both arguments, even if empty, to maintain consistent positional arguments
+    if special_deps:
+        args.extend(["--optional-deps", "#".join(special_deps)])
+    if external_provider_deps:
+        args.extend(
+            ["--external-provider-deps", "#".join(external_provider_deps)]
+        )  # the script will install external provider module, get its deps, and install those too.
+
+    return_code = run_command(args)
+
+    if return_code != 0:
+        log.error(
+            f"Failed to build target {image_name} with return code {return_code}",
+        )
+
+    return return_code