hub: Log adding tasks to Koji's db

Log both the entrypoint and the return value from adding a task to
Koji's database. We can measure both to ensure a task has been
successfully added to the database as a service level indicator.

plugins/hub/osbuild.py

@@ -1,5 +1,6 @@
 """Koji osbuild integration for Koji Hub"""
 import sys
+import logging
 import jsonschema
 
 import koji
@@ -231,6 +232,9 @@ def osbuildImage(name, version, distro, image_type, target, arches, opts=None, p
     context.session.assertPerm("image")
     args = [name, version, distro, image_type, target, arches, opts]
     task = {"channel": "image"}
+    logger = logging.getLogger('koji.plugins')
+
+    logger.info("Create osbuildImage task")
 
     try:
         jsonschema.validate(args, OSBUILD_IMAGE_SCHEMA)
@@ -246,4 +250,10 @@ def osbuildImage(name, version, distro, image_type, target, arches, opts=None, p
     if priority and priority < 0 and not context.session.hasPerm('admin'):
         raise koji.ActionNotAllowed('only admins may create high-priority tasks')
 
-    return kojihub.make_task('osbuildImage', args, **task)
+    # If task_id is returned from Koji Hub we assume
+    # that the task has been added to the database
+    task_id = kojihub.make_task('osbuildImage', args, **task)
+    if task_id:
+        logger.info("osbuildImage task %i added to database", task_id)
+
+    return task_id