Add MERGE_FAILURE buildset result

We now report a distinct buildset result to the database if the upstream code
review system is unable to merge a change.  Previously it was reported as
MERGE_CONFLICT which makes it difficult to distinguish from merge conflicts.

Essentially, the two states we're interested in are when Zuul's merger is
unable to prepare a git checkout of the change (99% of the time, this is
a merge conflict).  This is the MERGE_CONFLICT result.

The second state is when Zuul asks Gerrit/Github/etc to submit/merge a change
and the remote system is unable (or refuses) to do so.  This is MERGE_FAILURE.

Change-Id: I47af242aeb19ae4b4aedde353fcc76ff82d90fbe

releasenotes/notes/merge-failure-result-28bf93bec49b2b09.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    A new buildset result ``MERGE_FAILURE`` is stored in the build
+    database in the case where a buildset is unable to be merged by
+    the upstream code review system.

tests/unit/test_circular_dependencies.py

@@ -667,6 +667,12 @@ class TestGerritCircularDependencies(ZuulTestCase):
         self.assertEqual(A.data["status"], "NEW")
         self.assertEqual(B.data["status"], "NEW")
 
+        buildsets = {bs.change: bs for bs in
+                     self.scheds.first.connections.connections[
+                         'database'].getBuildsets()}
+        self.assertEqual(buildsets[2].result, 'MERGE_FAILURE')
+        self.assertEqual(buildsets[1].result, 'FAILURE')
+
     def test_cycle_reporting_partial_failure(self):
         A = self.fake_gerrit.addFakeChange("org/project", "master", "A")
         B = self.fake_gerrit.addFakeChange("org/project1", "master", "B")

tests/unit/test_scheduler.py

@@ -5229,6 +5229,19 @@ For CI problems and help debugging, contact ci@example.org"""
         self.assertNotIn('logs.example.com', B.messages[0])
         self.assertNotIn('SKIPPED', B.messages[0])
 
+    def test_submit_failure(self):
+        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
+        A.fail_merge = True
+
+        A.addApproval('Code-Review', 2)
+        self.fake_gerrit.addEvent(A.addApproval('Approved', 1))
+        self.waitUntilSettled()
+
+        buildsets = list(
+            self.scheds.first.connections.connections[
+                'database'].getBuildsets())
+        self.assertEqual(buildsets[0].result, 'MERGE_FAILURE')
+
     @simple_layout('layouts/nonvoting-pipeline.yaml')
     def test_nonvoting_pipeline(self):
         "Test that a nonvoting pipeline (experimental) can still report"

web/src/containers/build/Misc.jsx

@@ -63,6 +63,11 @@ const RESULT_ICON_CONFIGS = {
     color: 'var(--pf-global--warning-color--100)',
     badgeColor: 'orange',
   },
+  MERGE_FAILURE: {
+    icon: ExclamationIcon,
+    color: 'var(--pf-global--warning-color--100)',
+    badgeColor: 'orange',
+  },
   NODE_FAILURE: {
     icon: ExclamationIcon,
     color: 'var(--pf-global--warning-color--100)',

web/src/containers/charts/Misc.jsx

@@ -45,6 +45,11 @@ const buildResultLegendData = [
         // PF orange-200
         symbol: { fill: '#EF9234' },
     },
+    {
+        name: 'MERGE_FAILURE',
+        // PF orange-200
+        symbol: { fill: '#EF9234' },
+    },
     {
         name: 'NODE_FAILURE',
         // PF orange-300

web/src/pages/Builds.jsx

@@ -83,6 +83,7 @@ class BuildsPage extends React.Component {
           'SKIPPED',
           'NODE_FAILURE',
           'MERGE_CONFLICT',
+          'MERGE_FAILURE',
           'CONFIG_ERROR',
           'TIMED_OUT',
           'CANCELED',

web/src/pages/Buildsets.jsx

@@ -71,6 +71,7 @@ class BuildsetsPage extends React.Component {
           'SUCCESS',
           'FAILURE',
           'MERGE_CONFLICT',
+          'MERGE_FAILURE',
           'DEQUEUED',
         ]
       },

zuul/manager/__init__.py

@@ -1546,10 +1546,13 @@ class PipelineManager(metaclass=ABCMeta):
 
         actions = self.pipeline.failure_actions
         for ri in reported_items:
-            ri.setReportedResult('FAILURE')
             self.sendReport(actions, ri)
-            self.sql.reportBuildsetEnd(ri.current_build_set,
-                                       'failure', final=True)
+            if ri is not item:
+                # Don't override the reported sql result for the item
+                # that "really" failed.
+                ri.setReportedResult('FAILURE')
+                self.sql.reportBuildsetEnd(ri.current_build_set,
+                                           'failure', final=True)
 
     def processQueue(self):
         # Do whatever needs to be done for each change in the queue
@@ -1787,16 +1790,25 @@ class PipelineManager(metaclass=ABCMeta):
 
     def reportItem(self, item):
         log = get_annotated_logger(self.log, item.event)
+        action = None
         if not item.reported:
-            # _reportItem() returns True if it failed to report.
+            action, reported = self._reportItem(item)
             item.updateAttributes(self.current_context,
-                                  reported=not self._reportItem(item))
+                                  reported=reported)
         if self.changes_merge:
             succeeded = item.didAllJobsSucceed() and not item.isBundleFailing()
             merged = item.reported
             source = item.change.project.source
             if merged:
                 merged = source.isMerged(item.change, item.change.branch)
+            if action:
+                if action == 'success' and not merged:
+                    log.debug("Overriding result for %s to merge failure",
+                              item.change)
+                    action = 'merge-failure'
+                    item.setReportedResult('MERGE_FAILURE')
+                self.sql.reportBuildsetEnd(item.current_build_set,
+                                           action, final=True)
             change_queue = item.queue
             if not (succeeded and merged):
                 if (not item.current_build_set.job_graph or
@@ -1816,6 +1828,8 @@ class PipelineManager(metaclass=ABCMeta):
                 raise exceptions.MergeFailure(
                     "Change %s failed to merge" % item.change)
             else:
+                self.sql.reportBuildsetEnd(item.current_build_set,
+                                           action, final=True)
                 log.info("Reported change %s status: all-succeeded: %s, "
                          "merged: %s", item.change, succeeded, merged)
                 change_queue.increaseWindowSize()
@@ -1825,6 +1839,9 @@ class PipelineManager(metaclass=ABCMeta):
                 zuul_driver = self.sched.connections.drivers['zuul']
                 tenant = self.pipeline.tenant
                 zuul_driver.onChangeMerged(tenant, item.change, source)
+        elif action:
+            self.sql.reportBuildsetEnd(item.current_build_set,
+                                       action, final=True)
 
     def _reportItem(self, item):
         log = get_annotated_logger(self.log, item.event)
@@ -1922,8 +1939,7 @@ class PipelineManager(metaclass=ABCMeta):
             ret = self.sendReport(actions, item)
             if ret:
                 log.error("Reporting item %s received: %s", item, ret)
-        self.sql.reportBuildsetEnd(item.current_build_set, action, final=True)
-        return ret
+        return action, (not ret)
 
     def reportStats(self, item, added=False):
         if not self.sched.statsd:

zuul/reporter/__init__.py

@@ -123,6 +123,7 @@ class BaseReporter(object, metaclass=abc.ABCMeta):
             'success': self._formatItemReportSuccess,
             'failure': self._formatItemReportFailure,
             'merge-conflict': self._formatItemReportMergeConflict,
+            'merge-failure': self._formatItemReportMergeFailure,
             'no-jobs': self._formatItemReportNoJobs,
             'disabled': self._formatItemReportDisabled,
             'dequeue': self._formatItemReportDequeue,
@@ -198,6 +199,9 @@ class BaseReporter(object, metaclass=abc.ABCMeta):
     def _formatItemReportMergeConflict(self, item, with_jobs=True):
         return item.pipeline.merge_conflict_message
 
+    def _formatItemReportMergeFailure(self, item, with_jobs=True):
+        return 'This change was not merged by the code review system.\n'
+
     def _formatItemReportNoJobs(self, item, with_jobs=True):
         status_url = get_default(self.connection.sched.config,
                                  'web', 'status_url', '')