19449 Kubernetes: New supported versions policy

CMK-33724

Change-Id: I1b1194de1d1c1801fcb457a0414c831a37de5ea9

Author: relrod

.werks/19449.md

@@ -0,0 +1,35 @@
+[//]: # (werk v3)
+# Kubernetes: New supported versions policy
+
+key        | value
+---------- | ---
+date       | 2026-04-16T18:02:27.547689+00:00
+version    | 2.5.0p1
+class      | feature
+edition    | community
+component  | checks
+level      | 2
+compatible | no
+
+With this Werk, we introduce a new support policy for Kubernetes monitoring:
+starting with Checkmk 2.5.0, **4 Kubernetes versions are officially supported
+at any given time**.
+
+## Supported versions in Checkmk 2.5.0
+
+**1.30, 1.31, 1.32, 1.33**
+
+When support for Kubernetes 1.34 is announced in a later Werk, official support
+for 1.30 will end (upstream maintenance for 1.30 already ended in June 2025).
+
+## What this means for you
+
+If you are monitoring clusters running Kubernetes versions outside the
+supported range, consider upgrading those clusters. Monitoring may still work
+on older versions, and we will try to keep compatibility within reason, but we
+will not officially support or fix issues specific to unsupported versions.
+
+## Going forward
+
+Each time official support for a new Kubernetes version is added, a Werk will
+list the currently supported versions.

packages/cmk-plugins/cmk/plugins/kube/api_server.py

@@ -53,7 +53,7 @@
 
 LOGGER = logging.getLogger()
 VERSION_MATCH_RE = re.compile(r"\s*v?([0-9]+(?:\.[0-9]+)*).*")
-SUPPORTED_VERSIONS = [(1, 26), (1, 27), (1, 28), (1, 29), (1, 30), (1, 31), (1, 32), (1, 33)]
+SUPPORTED_VERSIONS = [(1, 30), (1, 31), (1, 32), (1, 33)]
 # PM decision: LOWEST_FUNCTIONING_VERSION is incremented, if an issue is reported by a customer.
 # Otherwise, we try not change anything in monitoring (despite lack of support).
 LOWEST_FUNCTIONING_VERSION = (1, 21)

packages/cmk-plugins/cmk/plugins/kube/special_agents/agent_kube.py

@@ -10,7 +10,7 @@
 Checkmk special agent for monitoring Kubernetes clusters.
 This agent is required for monitoring data provided by the Kubernetes API and the Checkmk collectors,
 which can optionally be deployed within a cluster.
-The agent requires Kubernetes version v1.26 or higher.
+The agent requires Kubernetes version v1.30 or higher.
 Moreover, read access to the Kubernetes API endpoints monitored by Checkmk must be provided.
 """
 

packages/cmk-plugins/tests/cmk/plugins/kube/utils_kubernetes/test_api_server.py

@@ -39,9 +39,7 @@ def _core_api() -> CoreAPI:
 
 
 CALL_API = "cmk.plugins.kube.api_server.send_request"
-SUPPORTED_VERSION_STR = (
-    "Supported versions are v1.26, v1.27, v1.28, v1.29, v1.30, v1.31, v1.32, v1.33."
-)
+SUPPORTED_VERSION_STR = "Supported versions are v1.30, v1.31, v1.32, v1.33."
 
 
 def test_raw_api_get_healthz_ok(core_api: CoreAPI) -> None:
@@ -303,11 +301,11 @@ def test_decompose_git_version(
             ],
         ),
         (
-            api.KubernetesVersion(git_version=api.GitVersion("v1.26.2"), major=1, minor=26),
+            api.KubernetesVersion(git_version=api.GitVersion("v1.30.2"), major=1, minor=30),
             [],
         ),
         (
-            api.KubernetesVersion(git_version=api.GitVersion("v1.27.0"), major=1, minor=27),
+            api.KubernetesVersion(git_version=api.GitVersion("v1.31.0"), major=1, minor=31),
             [],
         ),
         (