From bb0115808db9683ef317dd730f0583960b3c69b5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rn-Michael=20Miehe?=
 <40151420+ldericher@users.noreply.github.com>
Date: Sun, 18 Sep 2022 21:36:52 +0000
Subject: [PATCH] Exception based webdav_check; app startup

---
 api/ovdashboard_api/__main__.py   | 15 ++++-----
 api/ovdashboard_api/app.py        | 54 +++++++++++++++++--------------
 api/ovdashboard_api/dav_common.py |  8 ++---
 3 files changed, 39 insertions(+), 38 deletions(-)

diff --git a/api/ovdashboard_api/__main__.py b/api/ovdashboard_api/__main__.py
index e983129..0cb503d 100644
--- a/api/ovdashboard_api/__main__.py
+++ b/api/ovdashboard_api/__main__.py
@@ -1,20 +1,17 @@
 from uvicorn import run as uvicorn_run
 
-from .dav_common import webdav_check
-
 
 def main() -> None:
     """
     If the `main` script is run, `uvicorn` is used to run the app.
     """
 
-    if webdav_check():
-        uvicorn_run(
-            app="ovdashboard_api:app",
-            host="0.0.0.0",
-            port=8000,
-            reload=True,
-        )
+    uvicorn_run(
+        app="ovdashboard_api:app",
+        host="0.0.0.0",
+        port=8000,
+        reload=True,
+    )
 
 
 if __name__ == "__main__":
diff --git a/api/ovdashboard_api/app.py b/api/ovdashboard_api/app.py
index d9e0365..56bb583 100644
--- a/api/ovdashboard_api/app.py
+++ b/api/ovdashboard_api/app.py
@@ -10,6 +10,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.staticfiles import StaticFiles
 
+from .dav_common import webdav_check
 from .routers.v1 import router as v1_router
 from .settings import SETTINGS
 
@@ -29,28 +30,33 @@ app = FastAPI(
     redoc_url=SETTINGS.redoc_url,
 )
 
+app.add_event_handler("startup", webdav_check)
+
+
+@app.on_event("startup")
+async def add_middlewares() -> None:
+    if SETTINGS.production_mode:
+        # Mount frontend in production mode
+        app.mount(
+            path="/",
+            app=StaticFiles(
+                directory="/html",
+                html=True,
+            ),
+            name="frontend",
+        )
+
+    else:
+        # Allow CORS in debug mode
+        app.add_middleware(
+            CORSMiddleware,
+            allow_origins=[
+                "*",
+            ],
+            allow_credentials=True,
+            allow_methods=["*"],
+            allow_headers=["*"],
+            expose_headers=["*"],
+        )
+
 app.include_router(v1_router)
-
-if SETTINGS.production_mode:
-    # Mount frontend in production mode
-    app.mount(
-        path="/",
-        app=StaticFiles(
-            directory="/html",
-            html=True,
-        ),
-        name="frontend",
-    )
-
-else:
-    # Allow CORS in debug mode
-    app.add_middleware(
-        CORSMiddleware,
-        allow_origins=[
-            "*",
-        ],
-        allow_credentials=True,
-        allow_methods=["*"],
-        allow_headers=["*"],
-        expose_headers=["*"],
-    )
diff --git a/api/ovdashboard_api/dav_common.py b/api/ovdashboard_api/dav_common.py
index db96631..521faad 100644
--- a/api/ovdashboard_api/dav_common.py
+++ b/api/ovdashboard_api/dav_common.py
@@ -25,7 +25,7 @@ _WEBDAV_CLIENT = WebDAVclient({
 _logger = getLogger(__name__)
 
 
-def webdav_check() -> bool:
+def webdav_check() -> None:
     """
     Checks if base resources are available.
     """
@@ -53,7 +53,7 @@ def webdav_check() -> bool:
             "WebDAV connection to %s FAILED!",
             repr(SETTINGS.webdav.url),
         )
-        return False
+        raise ConnectionError(SETTINGS.webdav.url)
 
     _logger.debug("WebDAV connection ok.")
 
@@ -62,12 +62,10 @@ def webdav_check() -> bool:
             "WebDAV prefix directory %s NOT FOUND, please create it!",
             repr(SETTINGS.webdav_prefix),
         )
-        return False
+        raise FileNotFoundError(SETTINGS.webdav_prefix)
 
     _logger.debug("WebDAV prefix directory found.")
 
-    return True
-
 
 def webdav_ensure_path(remote_path: str) -> None:
     remote_path = f"{SETTINGS.webdav_prefix}/{remote_path}"