fix: add pebble log targets and checks to testing plan (#1111)

Issue: adding a layer with checks or log-targets isn't reflected
in the plan you obtain when testing through get_plan()

solution: make it reflect

ops/testing.py

@@ -2936,18 +2936,32 @@ def _render_services(self) -> Dict[str, pebble.Service]:
         for key in sorted(self._layers.keys()):
             layer = self._layers[key]
             for name, service in layer.services.items():
-                # TODO: (jam) 2021-04-07 have a way to merge existing services
+                # TODO: merge existing services https://github.com/canonical/operator/issues/1112
                 services[name] = service
         return services
 
+    def _render_checks(self) -> Dict[str, pebble.Check]:
+        checks: Dict[str, pebble.Check] = {}
+        for key in sorted(self._layers.keys()):
+            layer = self._layers[key]
+            for name, check in layer.checks.items():
+                checks[name] = check
+        return checks
+
+    def _render_log_targets(self) -> Dict[str, pebble.LogTarget]:
+        log_targets: Dict[str, pebble.LogTarget] = {}
+        for key in sorted(self._layers.keys()):
+            layer = self._layers[key]
+            for name, log_target in layer.log_targets.items():
+                log_targets[name] = log_target
+        return log_targets
+
     def get_plan(self) -> pebble.Plan:
         self._check_connection()
         plan = pebble.Plan('{}')
-        services = self._render_services()
-        if not services:
-            return plan
-        for name in sorted(services.keys()):
-            plan.services[name] = services[name]
+        plan.services.update(self._render_services())
+        plan.checks.update(self._render_checks())
+        plan.log_targets.update(self._render_log_targets())
         return plan
 
     def get_services(self, names: Optional[List[str]] = None) -> List[pebble.ServiceInfo]:

test/test_testing.py

@@ -2798,6 +2798,39 @@ def test_get_pebble_container_plan(self):
         harness_plan = harness.get_container_pebble_plan('foo')
         self.assertEqual(harness_plan.to_yaml(), plan.to_yaml())
 
+    def test_add_layer_with_log_targets_to_plan(self):
+        layer_yaml = '''\
+        services:
+         foo:
+          override: replace
+          command: echo foo
+
+        checks:
+         bar:
+          http:
+           https://example.com/
+
+        log-targets:
+         baz:
+          override: replace
+          type: loki
+          location: https://example.com:3100/loki/api/v1/push
+        '''
+        harness = ops.testing.Harness(ops.CharmBase, meta=yaml.safe_dump(
+            {'name': 'foo', "containers": {"consumer": {"type": "oci-image"}}}))
+        harness.begin()
+        harness.set_can_connect('consumer', True)
+
+        container = harness.charm.unit.containers["consumer"]
+        layer = pebble.Layer(layer_yaml)
+        container.add_layer('foo', layer)
+
+        plan = container.get_plan()
+
+        self.assertIsNotNone(plan.services.get('foo'))
+        self.assertIsNotNone(plan.checks.get('bar'))
+        self.assertIsNotNone(plan.log_targets.get('baz'))
+
     def test_get_pebble_container_plan_unknown(self):
         harness = ops.testing.Harness(ops.CharmBase, meta='''
             name: test-app