Create framework for error handling and handle connection errors

1 files changed, 36 insertions, 1 deletions

diff --git a/gn2/wqflask/app_errors.py b/gn2/wqflask/app_errors.py
index c6081e08..b0e3b665 100644
--- a/gn2/wqflask/app_errors.py
+++ b/gn2/wqflask/app_errors.py
@@ -1,9 +1,42 @@
 """Handle errors at the application's top-level"""
-from flask import flash, redirect, current_app, render_template
+import os
+import random
+import datetime
+import traceback
+
+from werkzeug.exceptions import InternalServerError
 from authlib.integrations.base_client.errors import InvalidTokenError
+from flask import (
+    flash, request, redirect, current_app, render_template, make_response)
 
 from gn2.wqflask.oauth2 import session
 from gn2.wqflask.decorators import AuthorisationError
+from gn2.wqflask.external_errors import ExternalRequestError
+
+def render_error(exc):
+    """Render the errors consistently."""
+    error_desc = str(exc)
+    time_str = datetime.datetime.utcnow().strftime('%l:%M%p UTC %b %d, %Y')
+    formatted_lines = f"{request.url} ({time_str}) \n{traceback.format_exc()}"
+
+    current_app.logger.error("(error-id: %s): %s\n\n%s",
+                             exc.errorid if hasattr(exc, "errorid") else uuid4(),
+                             error_desc,
+                             formatted_lines)
+
+    animation = request.cookies.get(error_desc[:32])
+    if not animation:
+        animation = random.choice([fn for fn in os.listdir(
+            "./gn2/wqflask/static/gif/error") if fn.endswith(".gif")])
+
+    resp = make_response(render_template(
+        "error.html",
+        message=error_desc,
+        stack={formatted_lines},
+        error_image=animation,
+        version=current_app.config.get("GN_VERSION")))
+    resp.set_cookie(error_desc[:32], animation)
+    return resp
 
 def handle_authorisation_error(exc: AuthorisationError):
     """Handle AuthorisationError if not handled anywhere else."""
@@ -20,6 +53,8 @@ def handle_invalid_token_error(exc: InvalidTokenError):
 
 __handlers__ = {
     AuthorisationError: handle_authorisation_error,
+    ExternalRequestError: lambda exc: render_error(exc),
+    InternalServerError: lambda exc: render_error(exc),
     InvalidTokenError: handle_invalid_token_error
 }