fix: Tolerate Pods without labels in metrics

Some Pods may not have labels, for example the Pods created by our CLI
during the restore process.

The deployed sessions collector should not fail when it hits such a Pod.
Instead, it should just ignore it.

backend/capellacollab/sessions/metrics.py

@@ -33,10 +33,13 @@ def collect(self) -> t.Iterable[prometheus_client.core.Metric]:
         )
         operator = operators.get_operator()
         pods = operator.get_pods(label_selector=None)
-        statuses = sorted(
-            (pod.metadata.labels.get("workload", ""), pod.status.phase.lower())
-            for pod in pods
-        )
+        statuses = []
+        for pod in pods:
+            labels = pod.metadata.labels
+            if labels is None or "workload" not in labels:
+                continue
+
+            statuses.append((labels["workload"], pod.status.phase.lower()))
         for labels, g in itertools.groupby(statuses):
             metric.add_metric(labels, len(list(g)))
         yield metric

backend/tests/test_metrics.py

@@ -1,9 +1,11 @@
 # SPDX-FileCopyrightText: Copyright DB InfraGO AG and contributors
 # SPDX-License-Identifier: Apache-2.0
 
+import pytest
 from fastapi import testclient
+from kubernetes import client as k8s_client
 
-from capellacollab.sessions import metrics, operators
+from capellacollab.sessions import metrics
 
 
 def test_metrics_endpoint(client: testclient.TestClient):
@@ -13,7 +15,7 @@ def test_metrics_endpoint(client: testclient.TestClient):
     assert "# HELP " in response.text
 
 
-def test_database_sessions_metric(db):
+def test_database_sessions_metric_empty():
     collector = metrics.DatabaseSessionsCollector()
 
     data = list(collector.collect())
@@ -22,10 +24,50 @@ def test_database_sessions_metric(db):
     assert data[0].samples
 
 
-def test_kubernetes_sessions_metric(monkeypatch):
-    monkeypatch.setattr(operators, "get_operator", MockOperator)
-    collector = metrics.DeployedSessionsCollector()
+def test_kubernetes_sessions_metric(monkeypatch: pytest.MonkeyPatch):
+    def mock_list_namespaced_pod(
+        self, namespace: str, label_selector: str
+    ) -> k8s_client.V1PodList:
+        return k8s_client.V1PodList(
+            items=[
+                k8s_client.V1Pod(
+                    metadata=k8s_client.V1ObjectMeta(),
+                    status=k8s_client.V1PodStatus(phase="running"),
+                ),
+                k8s_client.V1Pod(
+                    metadata=k8s_client.V1ObjectMeta(
+                        labels={"workload": "job"}
+                    ),
+                    status=k8s_client.V1PodStatus(phase="pending"),
+                ),
+                k8s_client.V1Pod(
+                    metadata=k8s_client.V1ObjectMeta(
+                        labels={"workload": "job"}
+                    ),
+                    status=k8s_client.V1PodStatus(phase="running"),
+                ),
+                k8s_client.V1Pod(
+                    metadata=k8s_client.V1ObjectMeta(
+                        labels={"workload": "session"}
+                    ),
+                    status=k8s_client.V1PodStatus(phase="running"),
+                ),
+                k8s_client.V1Pod(
+                    metadata=k8s_client.V1ObjectMeta(
+                        labels={"workload": "session"}
+                    ),
+                    status=k8s_client.V1PodStatus(phase="running"),
+                ),
+            ]
+        )
+
+    monkeypatch.setattr(
+        k8s_client.CoreV1Api,
+        "list_namespaced_pod",
+        mock_list_namespaced_pod,
+    )
 
+    collector = metrics.DeployedSessionsCollector()
     data = list(collector.collect())
 
     samples = {
@@ -38,30 +80,3 @@ def test_kubernetes_sessions_metric(monkeypatch):
         ("job", "pending"): 1,
         ("session", "running"): 2,
     }
-
-
-class MockOperator:
-    def get_pods(self, label_selector):
-        return [
-            attrdict(
-                metadata=attrdict(labels=dict(workload="job")),
-                status=attrdict(phase="running"),
-            ),
-            attrdict(
-                metadata=attrdict(labels=dict(workload="job")),
-                status=attrdict(phase="pending"),
-            ),
-            attrdict(
-                metadata=attrdict(labels=dict(workload="session")),
-                status=attrdict(phase="running"),
-            ),
-            attrdict(
-                metadata=attrdict(labels=dict(workload="session")),
-                status=attrdict(phase="running"),
-            ),
-        ]
-
-
-class attrdict(dict):
-    def __getattr__(self, name):
-        return self[name]