Add Zuul's event id to Ansible inventory

With the event id in the inventory we can use it in the emit-job-header
role. This can aid in debugging, e.g. when a job is still running.

Change-Id: Id2d38bb3d121fa9cf959b9765ac8025d42001c02

doc/source/reference/jobs.rst

@@ -309,6 +309,11 @@ of item.
 
       The name of the job being run.
 
+   .. var:: event_id
+
+      The UUID of the event that triggered this execution. This is mainly
+      useful for debugging purposes.
+
    .. var:: voting
 
       A boolean indicating whether the job is voting.

tests/unit/test_inventory.py

@@ -78,6 +78,7 @@ class TestInventoryGithub(TestInventoryBase):
         self.assertIn('executor', z_vars)
         self.assertIn('src_root', z_vars['executor'])
         self.assertIn('job', z_vars)
+        self.assertIn('event_id', z_vars)
         self.assertEqual(z_vars['job'], 'single-inventory')
         self.assertEqual(z_vars['message'], 'QQ==')
         self.assertEqual(z_vars['change_url'],

zuul/executor/client.py

@@ -165,6 +165,7 @@ class ExecutorClient(object):
                            project=project,
                            tenant=tenant.name,
                            timeout=job.timeout,
+                           event_id=item.event.zuul_event_id,
                            jobtags=sorted(job.tags),
                            _inheritance_path=list(job.inheritance_path))
         if job.artifact_data: