Set resource limits and requests for Tempo

charmcraft.yaml

@@ -141,8 +141,19 @@ config:
         Note that for a tempo deployment as a whole to be consistent, each role 
         (except the optional 'metrics-generator') needs to be assigned to at least one worker node. If this condition
         is not met, the coordinator charm will set blocked status and the deployment will shut down.
-
-
+    cpu_limit:
+      description: |
+        K8s cpu resource limit, e.g. "1" or "500m". Default is unset (no limit). This value is used
+        for the "limits" portion of the resource requirements.
+        See https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
+      type: string
+    memory_limit:
+      description: |
+        K8s memory resource limit, e.g. "1Gi". Default is unset (no limit). This value is used
+        for the "limits" portion of the resource requirements.
+        See https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
+      type: string
+
 # build info
 
 bases:

requirements.txt

@@ -1,8 +1,11 @@
-ops>=2.15
-cosl>=0.0.23
+ops >= 2.15
+cosl>=0.0.24
 
 # Charm relation interfaces
 pydantic>=2
 
 # lib/charms/tempo_k8s/v1/charm_tracing.py
-opentelemetry-exporter-otlp-proto-http==1.21.0
+opentelemetry-exporter-otlp-proto-http==1.21.0
+
+lightkube>=0.15.4
+lightkube-models==1.24.1.4

src/charm.py

@@ -8,7 +8,7 @@
 Integrate it with a `tempo-k8s` coordinator unit to start.
 """
 import logging
-from typing import Optional
+from typing import Optional, Dict
 
 from cosl.coordinated_workers.worker import CONFIG_FILE, Worker
 from ops import CollectStatusEvent
@@ -59,6 +59,8 @@ def __init__(self, *args):
             pebble_layer=self.generate_worker_layer,
             endpoints={"cluster": "tempo-cluster"},  # type: ignore
             readiness_check_endpoint=self.readiness_check_endpoint,
+            resources_requests=self.get_resources_requests,
+            container_name="tempo",
         )
         self.framework.observe(self.on.collect_unit_status, self._on_collect_status)
 
@@ -120,6 +122,10 @@ def _on_collect_status(self, e: CollectStatusEvent):
                 )
             )
 
+    def get_resources_requests(self, _) -> Dict[str, str]:
+        """Returns a dictionary for the "requests" portion of the resources requirements."""
+        return {"cpu": "50m", "memory": "200Mi"}
+
 
 if __name__ == "__main__":  # pragma: nocover
     main(TempoWorkerK8SOperatorCharm)

tests/scenario/conftest.py

@@ -3,6 +3,8 @@
 
 import pytest
 from scenario import Context, ExecOutput
+from ops import ActiveStatus
+from unittest.mock import patch
 
 from charm import TempoWorkerK8SOperatorCharm
 
@@ -18,8 +20,19 @@ def _urlopen_patch(url: str, resp, tls: bool = False):
 
 
 @pytest.fixture
-def ctx():
-    return Context(TempoWorkerK8SOperatorCharm)
+def worker_charm():
+    with patch.multiple(
+        "cosl.coordinated_workers.worker.KubernetesComputeResourcesPatch",
+        _namespace="test-namespace",
+        _patch=lambda _: None,
+        get_status=lambda _: ActiveStatus(""),
+    ):
+        yield TempoWorkerK8SOperatorCharm
+
+
+@pytest.fixture
+def ctx(worker_charm):
+    return Context(charm_type=worker_charm)
 
 
 TEMPO_VERSION_EXEC_OUTPUT = ExecOutput(stdout="1.31")

tests/scenario/test_status.py

@@ -9,13 +9,20 @@
 from ops import BlockedStatus
 from scenario import Context, State, Container, Relation, Mount
 
-from charm import TempoWorkerK8SOperatorCharm
 from tests.scenario.conftest import _urlopen_patch
+import json
+from unittest.mock import MagicMock
+
+from cosl.coordinated_workers.interface import ClusterRequirer
+from scenario import ExecOutput
+
+from tests.scenario.conftest import TEMPO_VERSION_EXEC_OUTPUT
+from tests.scenario.helpers import set_role
 
 
 @pytest.fixture
-def ctx():
-    return Context(TempoWorkerK8SOperatorCharm)
+def ctx(worker_charm):
+    return Context(worker_charm)
 
 
 @contextmanager
@@ -133,3 +140,77 @@ def test_status_check_ready(ctx, tmp_path):
         state_out = ctx.run("update_status", state)
     # THEN the charm sets waiting: Starting...
     assert state_out.unit_status == ActiveStatus("(all roles) ready.")
+
+
+@endpoint_ready
+@patch.object(ClusterRequirer, "get_worker_config", MagicMock(return_value={"config": "config"}))
+@patch(
+    "cosl.coordinated_workers.worker.KubernetesComputeResourcesPatch.get_status",
+    MagicMock(return_value=BlockedStatus("`juju trust` this application")),
+)
+def test_patch_k8s_failed(ctx):
+
+    tempo_container = Container(
+        "tempo",
+        can_connect=True,
+        exec_mock={
+            ("/bin/tempo", "-version"): TEMPO_VERSION_EXEC_OUTPUT,
+            ("update-ca-certificates", "--fresh"): ExecOutput(),
+        },
+    )
+    state_out = ctx.run(
+        "config_changed",
+        state=set_role(
+            State(
+                containers=[tempo_container],
+                relations=[
+                    Relation(
+                        "tempo-cluster",
+                        remote_app_data={
+                            "tempo_config": json.dumps({"alive": "beef"}),
+                        },
+                    )
+                ],
+            ),
+            "all",
+        ),
+    )
+
+    assert state_out.unit_status == BlockedStatus("`juju trust` this application")
+
+
+@endpoint_ready
+@patch.object(ClusterRequirer, "get_worker_config", MagicMock(return_value={"config": "config"}))
+@patch(
+    "cosl.coordinated_workers.worker.KubernetesComputeResourcesPatch.get_status",
+    MagicMock(return_value=WaitingStatus("")),
+)
+def test_patch_k8s_waiting(ctx):
+
+    tempo_container = Container(
+        "tempo",
+        can_connect=True,
+        exec_mock={
+            ("/bin/tempo", "-version"): TEMPO_VERSION_EXEC_OUTPUT,
+            ("update-ca-certificates", "--fresh"): ExecOutput(),
+        },
+    )
+    state_out = ctx.run(
+        "config_changed",
+        state=set_role(
+            State(
+                containers=[tempo_container],
+                relations=[
+                    Relation(
+                        "tempo-cluster",
+                        remote_app_data={
+                            "tempo_config": json.dumps({"alive": "beef"}),
+                        },
+                    )
+                ],
+            ),
+            "all",
+        ),
+    )
+
+    assert state_out.unit_status == WaitingStatus("")

tests/unit/test_charm.py

@@ -12,9 +12,16 @@
 
 ops.testing.SIMULATE_CAN_CONNECT = True
 
+k8s_resource_multipatch = patch.multiple(
+    "cosl.coordinated_workers.worker.KubernetesComputeResourcesPatch",
+    _namespace="test-namespace",
+    _patch=lambda _: None,
+)
+
 
 @patch("cosl.coordinated_workers.worker.Worker.running_version", lambda *_: "1.2.3")
 @patch("cosl.coordinated_workers.worker.Worker.restart", lambda *_: True)
+@k8s_resource_multipatch
 class TestCharm(unittest.TestCase):
     def setUp(self, *unused):
         self.harness = Harness(TempoWorkerK8SOperatorCharm)