RFC-0001-The-Llama-Stack (#8)

* RFC-0001-The-Llama-Stack

* Add OpenAPI generation utility, update SPEC to reflect latest types

* First cut at an observability API

* llama3_1 -> llama3

---------

Co-authored-by: Ashwin Bharambe <ashwin.bharambe@gmail.com>

rfcs/openapi_generator/generate.py

@@ -0,0 +1,111 @@
+# 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.
+
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described found in the
+# LICENSE file in the root directory of this source tree.
+
+import inspect
+
+from datetime import datetime
+from pathlib import Path
+from typing import Callable, Iterator, List, Tuple
+
+import fire
+import yaml
+
+from llama_models import schema_utils
+from pyopenapi import Info, operations, Options, Server, Specification
+
+# We do a series of monkey-patching to ensure our definitions only use the minimal
+# (json_schema_type, webmethod) definitions from the llama_models package. For
+# generation though, we need the full definitions and implementations from the
+#  (python-openapi, json-strong-typing) packages.
+
+from strong_typing.schema import json_schema_type
+from termcolor import colored
+
+schema_utils.json_schema_type = json_schema_type
+
+
+from llama_toolchain.stack import LlamaStack
+
+
+def patched_get_endpoint_functions(
+    endpoint: type, prefixes: List[str]
+) -> Iterator[Tuple[str, str, str, Callable]]:
+    if not inspect.isclass(endpoint):
+        raise ValueError(f"object is not a class type: {endpoint}")
+
+    functions = inspect.getmembers(endpoint, inspect.isfunction)
+    for func_name, func_ref in functions:
+        webmethod = getattr(func_ref, "__webmethod__", None)
+        if not webmethod:
+            continue
+
+        print(f"Processing {colored(func_name, 'white')}...")
+        operation_name = func_name
+        if operation_name.startswith("get_") or operation_name.endswith("/get"):
+            prefix = "get"
+        elif (
+            operation_name.startswith("delete_")
+            or operation_name.startswith("remove_")
+            or operation_name.endswith("/delete")
+            or operation_name.endswith("/remove")
+        ):
+            prefix = "delete"
+        else:
+            if webmethod.method == "GET":
+                prefix = "get"
+            elif webmethod.method == "DELETE":
+                prefix = "delete"
+            else:
+                # by default everything else is a POST
+                prefix = "post"
+
+        yield prefix, operation_name, func_name, func_ref
+
+
+# Patch this so all methods are correctly parsed with correct HTTP methods
+operations._get_endpoint_functions = patched_get_endpoint_functions
+
+
+def main(output_dir: str):
+    output_dir = Path(output_dir)
+    if not output_dir.exists():
+        raise ValueError(f"Directory {output_dir} does not exist")
+
+    now = str(datetime.now())
+    print(
+        "Converting the spec to YAML (openapi.yaml) and HTML (openapi.html) at " + now
+    )
+    print("")
+    spec = Specification(
+        LlamaStack,
+        Options(
+            server=Server(url="http://any-hosted-llama-stack.com"),
+            info=Info(
+                title="[DRAFT] Llama Stack Specification",
+                version="0.0.1",
+                description="""This is the specification of the llama stack that provides
+                a set of endpoints and their corresponding interfaces that are tailored to
+                best leverage Llama Models. The specification is still in draft and subject to change.
+                Generated at """
+                + now,
+            ),
+        ),
+    )
+    with open(output_dir / "llama-stack-spec.yaml", "w", encoding="utf-8") as fp:
+        yaml.dump(spec.get_json(), fp, allow_unicode=True)
+
+    with open(output_dir / "llama-stack-spec.html", "w") as fp:
+        spec.write_html(fp, pretty_print=True)
+
+
+if __name__ == "__main__":
+    fire.Fire(main)