Serve a better 404 page (#58)

* add the error stuff and redirect

* original url header

* get original url via header

* add base url

* optionally use header

---------

Co-authored-by: evan <evanuxd@gmail.com>

Author: n8thantran

modules/constants.py

@@ -1,10 +1,18 @@
 import enum
 
+NOT_FOUND_HTML = """
+<h1>Url not found.</h1>
+
+<p>The requested URL "{requested_url}" could not be found on this server.</p>
+
+<p>Return to <a href="{base_url}">homepage</a></p>
+"""
+
 class HttpResponse(enum.Enum):
 
   OK = (200, "success")
   BAD_REQUEST = (400, "<h1>No URL was found in your request</h1>")
-  NOT_FOUND = (404, "<h1>URL not found</h1>")
+  NOT_FOUND = (404, NOT_FOUND_HTML)
   CONFLICT = (409, "<h1>Alias already exists</h1>")
   INVALID_ARGUMENT_EXCEPTION = (422, "<h1>Alias is invalid</h1>")
   INTERNAL_SERVER_ERROR = (500, "<h1>Internal server error</h1>")

nginx.conf

@@ -16,6 +16,8 @@ http {
             resolver 127.0.0.11 valid=15s;
             proxy_set_header Host $host;
             set $upstream http://app:8000;
+            proxy_set_header X-Original-URL $http_x_original_url;
+            proxy_set_header X-Base-URL $http_x_base_url;
             proxy_pass $upstream;
             rewrite /s/(.*) /find/$1 break;
         }
@@ -28,6 +30,8 @@ http {
             resolver 127.0.0.11 valid=15s;
             proxy_set_header Host $host;
             set $upstream http://app:8000;
+            proxy_set_header X-Original-URL $http_x_original_url;
+            proxy_set_header X-Base-URL $http_x_base_url;
             proxy_pass $upstream;
             rewrite /qr/(.*) /qr/$1 break;
         }

server.py

@@ -175,8 +175,16 @@ async def qr(alias: str):
 @app.exception_handler(HTTPException)
 async def http_exception_handler(request, exc):
     status_code_enum = http_code_to_enum[exc.status_code]
+    content = status_code_enum.content
+    if status_code_enum == HttpResponse.NOT_FOUND:
+        original_url = request.headers.get("x-original-url", request.url)
+        base_url = request.headers.get("x-base-url", request.base_url)
+        content = content.format(
+            requested_url=str(original_url),
+            base_url=str(base_url)
+        )
     return HTMLResponse(
-        content=status_code_enum.content, status_code=status_code_enum.code
+        content=content, status_code=status_code_enum.code
     )