PTFE-1450 warn about failing queues

bert_e/exceptions.py

@@ -268,6 +268,11 @@ class RequestIntegrationBranches(TemplateException):
     status = "in_progress"
 
 
+class QueueBuildFailedMessage(TemplateException):
+    code = 136
+    template = "queue_build_failed.md"
+
+
 # internal exceptions
 class UnableToSendEmail(InternalException):
     code = 201
@@ -583,3 +588,7 @@ class JobSuccess(SilentException):
 
 class JobFailure(SilentException):
     code = 308
+
+
+class QueueBuildFailed(SilentException):
+    code = 309

bert_e/templates/queue_build_failed.md

@@ -0,0 +1,34 @@
+{% extends "message.md" %}
+
+{% block title -%}
+Queue build failed
+{% endblock %}
+
+{% block message %}
+
+The corresponding build for the queue failed:
+
+- Checkout the [status page]({{ frontend_url }}).
+- Identify the failing build and review the logs.
+- If no issue is found, re-run the build.
+- If an issue is identified, checkout the steps below to remove
+  the pull request from the queue for further analysis and maybe rebase/merge.
+
+<details>
+  <summary><b>Remove the pull request from the queue</b></summary>
+
+- Add a `/wait` comment on this pull request.
+- Click on login on the [status page]({{ frontend_url }}).
+- Go into the [manage]({{ frontend_url }}/manage) page.
+- Find the option called `Rebuild the queue` and click on it.
+  Bert-E will loop again on all pull requests to put the valid ones
+  in the queue again, while skipping the one with the `/wait` comment.
+- Wait for the new queue to merge, then merge/rebase your pull request
+  with the latest changes to then work on a proper fix.
+- Once the issue is fixed, delete the `/wait` comment and
+  follow the usual process to merge the pull request.
+
+</details>
+
+
+{% endblock %}

bert_e/tests/test_bert_e.py

@@ -5446,6 +5446,21 @@ def test_validation_with_failed_stabilization_branch_stacked(self):
         qc.validate()
         self.assertEqual(qc.mergeable_prs, [1])
 
+    def test_notify_pr_on_queue_fail(self):
+        pr = self.create_pr('bugfix/TEST-01', 'development/4.3')
+        with self.assertRaises(exns.Queued):
+            self.handle(pr.id, options=self.bypass_all, backtrace=True)
+        branch = f"q/{pr.id}/4.3/{pr.src_branch}"
+        self.set_build_status_on_branch_tip(branch, 'INPROGRESS')
+        with self.assertRaises(exns.NothingToDo):
+            self.handle(pr.id, options=self.bypass_all, backtrace=True)
+        self.set_build_status_on_branch_tip(branch, 'FAILED')
+        with self.assertRaises(exns.QueueBuildFailed):
+            self.handle(pr.id, options=self.bypass_all, backtrace=True)
+        # get last comment
+        comment = list(pr.get_comments())[-1].text
+        assert "Queue build failed" in comment
+
     def test_system_nominal_case(self):
         pr = self.create_pr('bugfix/TEST-00001', 'development/4.3')
         self.handle(pr.id,
@@ -5490,11 +5505,16 @@ def test_system_nominal_case(self):
         self.set_build_status_on_pr_id(pr.id, 'SUCCESSFUL')
         self.set_build_status(sha1=sha1_w_5_1, state='SUCCESSFUL')
         self.set_build_status(sha1=sha1_w_10_0, state='FAILED')
-        with self.assertRaises(exns.NothingToDo):
+        with self.assertRaises(exns.QueueBuildFailed):
             self.handle(pr.id, options=self.bypass_all, backtrace=True)
 
+        with self.assertRaises(exns.QueueBuildFailed):
+            self.handle(pr.src_commit, options=self.bypass_all, backtrace=True)
+
+        self.set_build_status(sha1=sha1_w_10_0, state='INPROGRESS')
         with self.assertRaises(exns.NothingToDo):
             self.handle(pr.src_commit, options=self.bypass_all, backtrace=True)
+
         self.set_build_status(sha1=sha1_w_10_0, state='SUCCESSFUL')
         with self.assertRaises(exns.Merged):
             self.handle(pr.src_commit, options=self.bypass_all, backtrace=True)
@@ -5937,7 +5957,7 @@ def test_pr_dev_and_hotfix_with_hotfix_merged_first(self):
         sha1 = self.set_build_status_on_branch_tip(
             'q/%d/10.0/bugfix/TEST-00001' % pr1.id, 'SUCCESSFUL')
 
-        with self.assertRaises(exns.NothingToDo):
+        with self.assertRaises(exns.QueueBuildFailed):
             self.handle(sha1, options=self.bypass_all, backtrace=True)
         self.assertEqual(self.prs_in_queue(), {pr0.id, pr1.id})
 
@@ -6059,6 +6079,12 @@ def test_pr_hotfix_alone(self):
 
         sha1 = self.set_build_status_on_branch_tip(
             'q/%d/10.0.0.1/bugfix/TEST-00000' % pr0.id, 'FAILED')
+        with self.assertRaises(exns.QueueBuildFailed):
+            self.handle(sha1, options=self.bypass_all, backtrace=True)
+        self.assertEqual(self.prs_in_queue(), {pr0.id})
+
+        sha1 = self.set_build_status_on_branch_tip(
+            'q/%d/10.0.0.1/bugfix/TEST-00000' % pr0.id, 'INPROGRESS')
         with self.assertRaises(exns.NothingToDo):
             self.handle(sha1, options=self.bypass_all, backtrace=True)
         self.assertEqual(self.prs_in_queue(), {pr0.id})
@@ -6110,7 +6136,7 @@ def test_multi_branch_queues(self):
         sha1 = self.set_build_status_on_branch_tip(
             'q/%d/10.0/bugfix/TEST-00003' % pr3.id, 'SUCCESSFUL')
 
-        with self.assertRaises(exns.NothingToDo):
+        with self.assertRaises(exns.QueueBuildFailed):
             self.handle(sha1, options=self.bypass_all, backtrace=True)
         self.assertEqual(self.prs_in_queue(), {pr1.id, pr2.id, pr3.id,
                                                pr4217.id})
@@ -6140,7 +6166,7 @@ def test_multi_branch_queues(self):
             'q/%d/5.1/bugfix/TEST-00004' % pr4.id, 'SUCCESSFUL')
         sha1 = self.set_build_status_on_branch_tip(
             'q/%d/10.0/bugfix/TEST-00004' % pr4.id, 'FAILED')
-        with self.assertRaises(exns.NothingToDo):
+        with self.assertRaises(exns.QueueBuildFailed):
             self.handle(sha1, options=self.bypass_all, backtrace=True)
         self.assertEqual(self.prs_in_queue(), {pr2.id, pr3.id, pr4.id})
 

bert_e/workflow/gitwaterflow/branches.py

@@ -548,6 +548,25 @@ def validate(self):
 
         self._validated = True
 
+    @property
+    def failed_prs(self):
+        """Return a list PRs in which the build have failed in the queue."""
+        if not self._validated:
+            raise errors.QueuesNotValidated()
+
+        failed = []
+        for version in self._queues.keys():
+            qint = self._queues[version][QueueIntegrationBranch]
+            if qint:
+                qint = qint[0]
+                status = self.bbrepo.get_build_status(
+                    qint.get_latest_commit(),
+                    self.build_key
+                )
+                if status == 'FAILED':
+                    failed.append(qint.pr_id)
+        return failed
+
     def _recursive_lookup(self, queues):
         """Given a set of queues, remove all queues that can't be merged,
         based on the build status obtained from the repository manager.

bert_e/workflow/gitwaterflow/queueing.py

@@ -29,9 +29,30 @@
                        build_queue_collection)
 from .integration import get_integration_branches
 from typing import List
+
+
 LOG = logging.getLogger(__name__)
 
 
+def notify_queue_build_failed(failed_prs: List[int], job: QueuesJob):
+    """Notify on the pull request that the queue build failed."""
+    # TODO: As this feature evolves, we might want to include
+    # the list of failed q/ branches in the message.
+    # Currently the drawback is that if the template changes a lot
+    # (one branch mentioned then two, then back to one)
+    # we will be sending multiple notifications to the user,
+    # in some cases with no good reason, and in other cases with a good reason.
+    # This becomes less of an issue if we focus on notifying the user
+    # only through build status checks.
+    for pr_id in failed_prs:
+        pull_request = job.project_repo.get_pull_request(pr_id)
+        notify_user(
+            job.settings, pull_request, exceptions.QueueBuildFailedMessage(
+                active_options=job.active_options,
+                frontend_url=job.bert_e.settings.frontend_url)
+        )
+
+
 @job_handler(QueuesJob)
 def handle_merge_queues(job):
     """Check merge queue and fast-forward development branches to the most
@@ -48,7 +69,12 @@ def handle_merge_queues(job):
     job.bert_e.update_queue_status(queues)
 
     if not queues.mergeable_prs:
-        raise exceptions.NothingToDo()
+        failed_prs = queues.failed_prs
+        if not failed_prs:
+            raise exceptions.NothingToDo()
+        else:
+            notify_queue_build_failed(failed_prs, job)
+            raise exceptions.QueueBuildFailed()
 
     merge_queues(queues.mergeable_queues)