GPT4All API Scaffolding. Matches OpenAI OpenAPI spec for chats and completions (#839)

* GPT4All API Scaffolding. Matches OpenAI OpenAI spec for engines, chats and completions

* Edits for docker building

* FastAPI app builds and pydantic models are accurate

* Added groovy download into dockerfile

* improved dockerfile

* Chat completions endpoint edits

* API uni test sketch

* Working example of groovy inference with open ai api

* Added lines to test

* Set default to mpt

gpt4all-api/gpt4all_api/app/main.py

@@ -0,0 +1,61 @@
+import os
+import docs
+import logging
+from fastapi import FastAPI, HTTPException, Request
+from starlette.middleware.cors import CORSMiddleware
+from fastapi.logger import logger as fastapi_logger
+from api_v1.settings import settings
+from api_v1.api import router as v1_router
+from api_v1 import events
+import os
+
+logger = logging.getLogger(__name__)
+
+app = FastAPI(title='GPT4All API', description=docs.desc)
+
+#CORS Configuration (in-case you want to deploy)
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["GET", "POST", "OPTIONS"],
+    allow_headers=["*"],
+)
+
+logger.info('Adding v1 endpoints..')
+
+# add v1
+app.include_router(v1_router, prefix='/v1')
+app.add_event_handler('startup', events.startup_event_handler(app))
+app.add_exception_handler(HTTPException, events.on_http_error)
+
+@app.on_event("startup")
+async def startup():
+    global model
+    logger.info(f"Downloading/fetching model: {os.path.join(settings.gpt4all_path, settings.model)}")
+    from gpt4all import GPT4All
+    model = GPT4All(model_name=settings.model, model_path=settings.gpt4all_path)
+
+    logger.info("GPT4All API is ready.")
+
+@app.on_event("shutdown")
+async def shutdown():
+    logger.info("Shutting down API")
+
+
+# This is needed to get logs to show up in the app
+if "gunicorn" in os.environ.get("SERVER_SOFTWARE", ""):
+    gunicorn_error_logger = logging.getLogger("gunicorn.error")
+    gunicorn_logger = logging.getLogger("gunicorn")
+
+    root_logger = logging.getLogger()
+    fastapi_logger.setLevel(gunicorn_logger.level)
+    fastapi_logger.handlers = gunicorn_error_logger.handlers
+    root_logger.setLevel(gunicorn_logger.level)
+
+    uvicorn_logger = logging.getLogger("uvicorn.access")
+    uvicorn_logger.handlers = gunicorn_error_logger.handlers
+else:
+    # https://github.com/tiangolo/fastapi/issues/2019
+    LOG_FORMAT2 = "[%(asctime)s %(process)d:%(threadName)s] %(name)s - %(levelname)s - %(message)s | %(filename)s:%(lineno)d"
+    logging.basicConfig(level=logging.INFO, format=LOG_FORMAT2)