Move error handling into separate package.

5 files changed, 88 insertions, 26 deletions

diff --git a/gn_auth/errors.py b/gn_auth/errors/__init__.py
index 4b6007a..533a842 100644
--- a/gn_auth/errors.py
+++ b/gn_auth/errors/__init__.py
@@ -1,38 +1,26 @@
 """Handle application level errors."""
+import logging
 import traceback
 
-from werkzeug.exceptions import NotFound
-from flask import Flask, request, jsonify, current_app, render_template
+from werkzeug.exceptions import NotFound, HTTPException
+from flask import (Flask,
+                   request,
+                   jsonify,
+                   render_template)
 
 from gn_auth.auth.errors import AuthorisationError
 
-def add_trace(exc: Exception, errobj: dict) -> dict:
-    """Add the traceback to the error handling object."""
-    current_app.logger.error("Endpoint: %s\n%s",
-                             request.url,
-                             traceback.format_exception(exc))
-    return {
-        **errobj,
-        "error-trace": "".join(traceback.format_exception(exc))
-    }
+from .tracing import add_trace
+from .http import http_error_handlers
 
-def page_not_found(exc):
-    """404 handler."""
-    current_app.logger.error(f"Page '{request.url}' was not found.", exc_info=True)
-    content_type = request.content_type
-    if bool(content_type) and content_type.lower() == "application/json":
-        return jsonify(add_trace(exc, {
-            "error": exc.name,
-            "error_description": (f"The page '{request.url}' does not exist on "
-                                  "this server.")
-        })), exc.code
+logger = logging.getLogger(__name__)
 
-    return render_template("404.html", page=request.url), exc.code
+__all__ = ["register_error_handlers"]
 
 
 def handle_general_exception(exc: Exception):
     """Handle generic unhandled exceptions."""
-    current_app.logger.error("Error occurred!", exc_info=True)
+    logger.error("Error occurred!", exc_info=True)
     content_type = request.content_type
     if bool(content_type) and content_type.lower() == "application/json":
         exc_args = [str(x) for x in exc.args]
@@ -51,19 +39,24 @@ def handle_general_exception(exc: Exception):
 
 def handle_authorisation_error(exc: AuthorisationError):
     """Handle AuthorisationError if not handled anywhere else."""
-    current_app.logger.error("Error occurred!", exc_info=True)
-    current_app.logger.error(exc)
+    logger.error("Error occurred!", exc_info=True)
+    logger.error(exc)
     return jsonify(add_trace(exc, {
         "error": type(exc).__name__,
         "error_description": " :: ".join(exc.args)
     })), exc.error_code
 
 __error_handlers__ = {
-    NotFound: page_not_found,
     Exception: handle_general_exception,
     AuthorisationError: handle_authorisation_error
 }
+
+
 def register_error_handlers(app: Flask):
     """Register ALL defined error handlers"""
+    _handlers = {
+        **__error_handlers__,
+        **http_error_handlers()
+    }
     for class_, error_handler in __error_handlers__.items():
         app.register_error_handler(class_, error_handler)
diff --git a/gn_auth/errors/http/__init__.py b/gn_auth/errors/http/__init__.py
new file mode 100644
index 0000000..f4164d1
--- /dev/null
+++ b/gn_auth/errors/http/__init__.py
@@ -0,0 +1,13 @@
+"""HTTP error handlers."""
+
+from .http_4xx_errors import http_4xx_error_handlers
+from .http_5xx_errors import http_5xx_error_handlers
+
+__all__ = ["http_error_handlers"]
+
+def http_error_handlers() -> dict:
+    """Return *ALL* HTTP error handlers."""
+    return {
+        **http_4xx_error_handlers(),
+        **http_5xx_error_handlers()
+    }
diff --git a/gn_auth/errors/http/http_4xx_errors.py b/gn_auth/errors/http/http_4xx_errors.py
new file mode 100644
index 0000000..704f11b
--- /dev/null
+++ b/gn_auth/errors/http/http_4xx_errors.py
@@ -0,0 +1,31 @@
+"""Handlers for HTTP 4** errors"""
+import logging
+from werkzeug.exceptions import NotFound
+
+from flask import request, jsonify, render_template
+
+from gn_auth.errors.tracing import add_trace
+
+__all__ = ["http_4xx_error_handlers"]
+
+logger = logging.getLogger(__name__)
+
+def page_not_found(exc):
+    """404 handler."""
+    logger.error("Page '%s' was not found.", request.url, exc_info=True)
+    content_type = request.content_type
+    if bool(content_type) and content_type.lower() == "application/json":
+        return jsonify(add_trace(exc, {
+            "error": exc.name,
+            "error_description": (f"The page '{request.url}' does not exist on "
+                                  "this server.")
+        })), exc.code
+
+    return render_template("404.html", page=request.url), exc.code
+
+
+def http_4xx_error_handlers() -> dict:
+    """Return handlers for HTTP errors in the 400-499 range"""
+    return {
+        NotFound: page_not_found
+    }
diff --git a/gn_auth/errors/http/http_5xx_errors.py b/gn_auth/errors/http/http_5xx_errors.py
new file mode 100644
index 0000000..71d09d8
--- /dev/null
+++ b/gn_auth/errors/http/http_5xx_errors.py
@@ -0,0 +1,7 @@
+"""Handlers for HTTP 5** errors."""
+
+__all__ = ["http_5xx_error_handlers"]
+
+def http_5xx_error_handlers() -> dict:
+    """Return handlers for HTTP errors in the 500-599 range"""
+    return {}
diff --git a/gn_auth/errors/tracing.py b/gn_auth/errors/tracing.py
new file mode 100644
index 0000000..25b544f
--- /dev/null
+++ b/gn_auth/errors/tracing.py
@@ -0,0 +1,18 @@
+"""Utilities for improving error tracing."""
+import logging
+import traceback
+
+from flask import request
+
+logger = logging.getLogger(__name__)
+
+
+def add_trace(exc: Exception, errobj: dict) -> dict:
+    """Add the traceback to the error handling object."""
+    logger.error("Endpoint: %s\n%s",
+                 request.url,
+                 traceback.format_exception(exc))
+    return {
+        **errobj,
+        "error-trace": "".join(traceback.format_exception(exc))
+    }