From f28dc70181f9f8cbb0e385ae0f8609364c304357 Mon Sep 17 00:00:00 2001
From: Oleg Silkin <o.silkin98@gmail.com>
Date: Fri, 6 Sep 2019 20:27:14 -0400
Subject: [PATCH] Adds slack webhook for error logging

---
 src/server/app.py     | 30 ++++++++++++++++++++++++++++++
 src/server/handles.py |  9 +++++----
 src/server/misc.py    | 11 +++++++++--
 test/test_server.py   |  4 ++++
 4 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/src/server/app.py b/src/server/app.py
index bc4c7e1..afc1723 100644
--- a/src/server/app.py
+++ b/src/server/app.py
@@ -3,10 +3,13 @@ import logging
 import pathlib
 import signal
 import time
+import queue
+
 
 import aiojobs
 import aiojobs.aiohttp
 import asyncio
+import aiohttp
 from aiohttp import web
 
 from src.database.queries import setup_database, backup_database
@@ -35,6 +38,24 @@ async def database_backup_routine(app):
         pass
 
 
+async def post_errors_to_slack(client, app):
+    while app['errors'].qsize() > 0:
+        msg = app['errors'].get_nowait()
+        if 'slack_webhook' in app['config']:
+            await client.post(app['config']['slack_webhook'], json=msg)
+
+
+async def report_errors_to_slack_webhook(app):
+    async with aiohttp.ClientSession() as client:
+        try:
+            while True:
+                await asyncio.shield(post_errors_to_slack(client, app))
+                await asyncio.sleep(300)
+
+        except asyncio.CancelledError:
+            await asyncio.shield(post_errors_to_slack(client, app))
+
+
 async def start_background_tasks(app):
     app['reader'] = obtain_connection(app['db_path'], True)
     app['waitful_backup'] = asyncio.create_task(database_backup_routine(app))
@@ -42,6 +63,9 @@ async def start_background_tasks(app):
     app['db_writer'] = DatabaseWriter(app['db_path'])
     app['writer'] = app['db_writer'].connection
 
+    app['errors'] = queue.Queue()
+    app['slack_webhook'] = asyncio.create_task(report_errors_to_slack_webhook(app))
+
 
 async def close_database_connections(app):
     logger.info('Ending background backup loop')
@@ -52,6 +76,11 @@ async def close_database_connections(app):
     app['db_writer'].cleanup()
 
 
+async def stop_reporting_errors(app):
+    app['slack_webhook'].cancel()
+    await app['slack_webhook']
+
+
 async def close_comment_scheduler(app):
     logger.info('Closing comment_scheduler')
     await app['comment_scheduler'].close()
@@ -72,6 +101,7 @@ class CommentDaemon:
         app.on_startup.append(start_background_tasks)
         app.on_shutdown.append(close_comment_scheduler)
         app.on_cleanup.append(close_database_connections)
+        app.on_cleanup.append(stop_reporting_errors)
         aiojobs.aiohttp.setup(app, **kwargs)
         app.add_routes([
             web.post('/api', api_endpoint),
diff --git a/src/server/handles.py b/src/server/handles.py
index f098a99..b769178 100644
--- a/src/server/handles.py
+++ b/src/server/handles.py
@@ -91,11 +91,12 @@ async def process_json(app, body: dict) -> dict:
                 result = METHODS[method](app, params)
             response['result'] = result
         except Exception as err:
-            logger.exception(f'Got {type(err).__name__}: {err}')
+            logger.exception(f'Got {type(err).__name__}:')
             if type(err) in (ValueError, TypeError):
-                response['error'] = make_error('INVALID_PARAMS', err)
+                response['error'] = make_error('INVALID_PARAMS', err, app)
             else:
-                response['error'] = make_error('INTERNAL', err)
+                response['error'] = make_error('INTERNAL', err, app)
+
         finally:
             end = time.time()
             logger.debug(f'Time taken to process {method}: {end - start} secs')
@@ -122,7 +123,7 @@ async def api_endpoint(request: web.Request):
             else:
                 return web.json_response(await process_json(request.app, body))
     except Exception as e:
-        return make_error('INVALID_REQUEST', e)
+        return make_error('INVALID_REQUEST', e, request.app)
 
 
 async def get_api_endpoint(request: web.Request):
diff --git a/src/server/misc.py b/src/server/misc.py
index 897a54b..5c181ac 100644
--- a/src/server/misc.py
+++ b/src/server/misc.py
@@ -31,11 +31,18 @@ ERRORS = {
 }
 
 
-def make_error(error, exc=None) -> dict:
+def make_error(error, exc=None, app=None) -> dict:
     body = ERRORS[error] if error in ERRORS else ERRORS['INTERNAL']
     try:
         if exc:
-            body.update({type(exc).__name__: str(exc)})
+            exc_name = type(exc).__name__
+            body.update({exc_name: str(exc)})
+
+            if app:
+                app['errors'].put_nowait({
+                    "text": f"Got `{exc_name}`: ```\n{exc}```"
+                })
+
     finally:
         return body
 
diff --git a/test/test_server.py b/test/test_server.py
index 8ba5296..b9282ee 100644
--- a/test/test_server.py
+++ b/test/test_server.py
@@ -13,6 +13,10 @@ from src.server import app
 from test.testcase import AsyncioTestCase
 
 
+if 'slack_webhook' in config:
+    config.pop('slack_webhook')
+
+
 fake = faker.Faker()
 fake.add_provider(internet)
 fake.add_provider(lorem)