[IMP] monitoring_status: check the db is reachable

make a real SQL query on GET /monitoring/status and return a 503
if the query failed.

monitoring_status/controllers/main.py

@@ -4,9 +4,12 @@
 import logging
 import json
 
+import psycopg2
+
 import werkzeug
 
 from odoo import http
+from odoo.http import request
 from odoo.addons.web.controllers.main import ensure_db
 
 
@@ -30,10 +33,24 @@ class Monitoring(http.Controller):
     @http.route('/monitoring/status', type='http', auth='none')
     def status(self):
         ensure_db()
+        http_status = 200
         # TODO: add 'sub-systems' status and infos:
         # queue job, cron, database, ...
         headers = {'Content-Type': 'application/json'}
         info = {'status': 1}
+        # check the database connection
+        try:
+            cr = request.env.cr
+            cr.execute(
+                'SELECT value '
+                'FROM ir_config_parameter '
+                'WHERE key=%s',
+                ('web.base.url',))
+            result = cr.fetchone()
+            info['web.base.url'] = result or ''
+        except psycopg2.OperationalError as exc:
+            info['database_error'] = str(exc)
+            http_status = 503
         session = http.request.session
         # We set a custom expiration of 1 second for this request, as we do a
         # lot of health checks, we don't want those anonymous sessions to be
@@ -43,4 +60,6 @@ class Monitoring(http.Controller):
         # Redis.
         if not session.uid:
             session.expiration = 1
-        return werkzeug.wrappers.Response(json.dumps(info), headers=headers)
+        return werkzeug.wrappers.Response(
+            json.dumps(info), status=http_status, headers=headers
+        )