From 9bc2bbbedfe701c26d0ed06f8247538072f9eccf Mon Sep 17 00:00:00 2001
From: MoritzWeber <kontakt@moritz-weber.net>
Date: Thu, 18 Jul 2024 17:59:07 +0200
Subject: [PATCH] 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 | 11 ++--
 backend/tests/test_metrics.py             | 79 ++++++++++++++---------
 2 files changed, 54 insertions(+), 36 deletions(-)

diff --git a/backend/capellacollab/sessions/metrics.py b/backend/capellacollab/sessions/metrics.py
index ef430823b..960a2e551 100644
--- a/backend/capellacollab/sessions/metrics.py
+++ b/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
diff --git a/backend/tests/test_metrics.py b/backend/tests/test_metrics.py
index d0f69c2ae..49aeab99f 100644
--- a/backend/tests/test_metrics.py
+++ b/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]