Warn user when dynamic layout ignores zuul config

Zuul loads configuration files in a distinct order and currently only
warns to the zuul log if some files got ignored. This can be confusing
to the user so plumb this warning through to the buildset which then
gets reported to a change.

Change-Id: I68f729c83cf6c16fd1f490a60b269401236ef6d9

tests/fixtures/config/split-config/git/common-config/zuul.d/org-project.yaml

@@ -1,3 +1,8 @@
+- project:
+    check:
+      jobs:
+        - project-test1
+
 - project:
     name: org/project
     check:

tests/unit/test_configloader.py

@@ -433,17 +433,25 @@ class TestSplitConfig(ZuulTestCase):
                                                files=file_dict)
             self.fake_gerrit.addEvent(A.getPatchsetCreatedEvent(1))
             self.waitUntilSettled()
+            return A
 
         log_fixture = self.useFixture(
             fixtures.FakeLogger(level=logging.WARNING))
 
         log_fixture._output.truncate(0)
-        add_file("common-config", "zuul.yaml")
-        self.assertIn("Multiple configuration", log_fixture.output)
+        A = add_file("common-config", "zuul.yaml")
+        self.assertIn("Configuration in common-config/zuul.d/jobs.yaml@master "
+                      "ignored because project-branch is already configured",
+                      log_fixture.output)
+        self.assertIn("Configuration in common-config/zuul.d/jobs.yaml@master "
+                      "ignored because project-branch is already configured",
+                      A.messages[0])
 
         log_fixture._output.truncate(0)
         add_file("org/project1", ".zuul.yaml")
-        self.assertIn("Multiple configuration", log_fixture.output)
+        self.assertIn("Configuration in org/project1/.zuul.d/gate.yaml@master "
+                      "ignored because project-branch is already configured",
+                      log_fixture.output)
 
 
 class TestConfigConflict(ZuulTestCase):

zuul/configloader.py

@@ -2260,8 +2260,9 @@ class ConfigLoader(object):
         return new_abide
 
     def _loadDynamicProjectData(self, config, project,
-                                files, trusted, tenant, loading_errors,
+                                files, trusted, item, loading_errors,
                                 pcontext):
+        tenant = item.pipeline.tenant
         tpc = tenant.project_configs[project.canonical_name]
         if trusted:
             branches = ['master']
@@ -2318,7 +2319,12 @@ class ConfigLoader(object):
                         conf_root not in tpc.extra_config_dirs):
                         if loaded and loaded != conf_root:
                             self.log.warning(
-                                "Multiple configuration in %s" %
+                                "Configuration in %s ignored because "
+                                "project-branch is already configured",
+                                source_context)
+                            item.warning(
+                                "Configuration in %s ignored because "
+                                "project-branch is already configured" %
                                 source_context)
                             continue
                         loaded = conf_root
@@ -2336,9 +2342,10 @@ class ConfigLoader(object):
                     config.extend(self.tenant_parser.parseConfig(
                         tenant, incdata, loading_errors, pcontext))
 
-    def createDynamicLayout(self, tenant, files, ansible_manager,
+    def createDynamicLayout(self, item, files, ansible_manager,
                             include_config_projects=False,
                             zuul_event_id=None):
+        tenant = item.pipeline.tenant
         log = get_annotated_logger(self.log, zuul_event_id)
         pcontext = ParseContext(self.connections, self.scheduler,
                                 tenant, ansible_manager)
@@ -2347,12 +2354,12 @@ class ConfigLoader(object):
             config = model.ParsedConfig()
             for project in tenant.config_projects:
                 self._loadDynamicProjectData(config, project, files, True,
-                                             tenant, loading_errors, pcontext)
+                                             item, loading_errors, pcontext)
         else:
             config = tenant.config_projects_config.copy()
 
         for project in tenant.untrusted_projects:
-            self._loadDynamicProjectData(config, project, files, False, tenant,
+            self._loadDynamicProjectData(config, project, files, False, item,
                                          loading_errors, pcontext)
 
         layout = model.Layout(tenant)

zuul/manager/__init__.py

@@ -568,7 +568,7 @@ class PipelineManager(metaclass=ABCMeta):
             if trusted_updates:
                 log.debug("Loading dynamic layout (phase 1)")
                 trusted_layout = loader.createDynamicLayout(
-                    item.pipeline.tenant,
+                    item,
                     build_set.files,
                     self.sched.ansible_manager,
                     include_config_projects=True,
@@ -580,7 +580,7 @@ class PipelineManager(metaclass=ABCMeta):
             if untrusted_updates:
                 log.debug("Loading dynamic layout (phase 2)")
                 untrusted_layout = loader.createDynamicLayout(
-                    item.pipeline.tenant,
+                    item,
                     build_set.files,
                     self.sched.ansible_manager,
                     include_config_projects=False,