17041 FIX apt: Show correct value if metrics if there are no updates

If there were no updates pending the metrics showed 'n/a' as the value.
This has now been fixed and they will show 0 as the value.

SUP-21419

Change-Id: I0596e980c54d487327c8a7eec7dd20feb656d9bc

.werks/17041.md

@@ -0,0 +1,15 @@
+[//]: # (werk v2)
+# apt: Show correct value if metrics if there are no updates
+
+key        | value
+---------- | ---
+date       | 2024-12-02T14:15:07+00:00
+version    | 2.3.0p22
+class      | fix
+edition    | cre
+component  | checks
+level      | 1
+compatible | yes
+
+If there were no updates pending the metrics showed 'n/a' as the value.
+This has now been fixed and they will show 0 as the value.

cmk/plugins/collection/agent_based/apt.py

@@ -243,6 +243,8 @@ def check_apt(params: Mapping[str, Any], section: Section) -> CheckResult:
 
     if section.n_updates == 0:
         yield Result(state=State.OK, summary=NOTHING_PENDING_FOR_INSTALLATION)
+        yield Metric(name="normal_updates", value=0)
+        yield Metric(name="security_updates", value=0)
         return
 
     yield Result(

tests/unit/cmk/plugins/collection/agent_based/test_apt.py

@@ -257,7 +257,11 @@ def test_apt_discovery() -> None:
         pytest.param(
             DEFAULT_PARAMS,
             Section([], [], []),
-            [Result(state=State.OK, summary="No updates pending for installation")],
+            [
+                Result(state=State.OK, summary="No updates pending for installation"),
+                Metric("normal_updates", 0.0),
+                Metric("security_updates", 0.0),
+            ],
             id="Nothing pending for installation.",
         ),
         pytest.param(