Revise scs-0214-v2: remove nonsensical regulation (#1163)

Closes #1152

Also: retire k8s_version_policy_test.py

Signed-off-by: Matthias Büchse <matthias.buechse@alasca.cloud>

Author: mbuechse

Standards/scs-0214-v2-k8s-node-distribution.md

@@ -69,9 +69,7 @@ to provide a fault-tolerant and available Kubernetes cluster infrastructure.
 
 The control plane nodes MUST be distributed over multiple physical machines.
 Kubernetes provides [best-practices][k8s-zones] on this topic, which are also RECOMMENDED by SCS.
-
-At least one control plane instance MUST be run in each "failure zone" used for the cluster,
-more instances per "failure zone" are possible to provide fault-tolerance inside a zone.
+In particular, the control plane nodes SHOULD be distributed over multiple failure zones.
 
 Worker nodes are RECOMMENDED to be distributed over multiple zones. This policy makes
 it OPTIONAL to provide a worker node in each "failure zone", meaning that worker nodes

Standards/scs-0214-w1-k8s-node-distribution-implementation-testing.md

@@ -20,11 +20,12 @@ Node distribution metadata is provided through the usage of the labels
 ## Automated tests
 
 Currently, automated testing is not readily possible because we cannot access information about
-the underlying host of a node (as opposed to its region and zone). Therefore, the test will only output
-a tentative result.
+the underlying host of a node (as opposed to its region and zone). Besides, access to
+control-plane nodes is problematic outside of a kubeadm-based setup.
 
-The current implementation can be found in the script [`k8s_node_distribution_check.py`](https://github.com/SovereignCloudStack/standards/blob/main/Tests/kaas/k8s-node-distribution/k8s_node_distribution_check.py).
+Therefore, no automated tests are performed at this time.
 
 ## Manual tests
 
-None.
+Cloud-service providers must confirm that control plane nodes are indeed distributed over
+multiple physical machines.

…8s-node-distribution/check_nodes_test.py …distribution_RETIRED/check_nodes_test.pyTests/kaas/k8s-node-distribution/check_nodes_test.py renamed to Tests/kaas/scs_0214_node_distribution_RETIRED/check_nodes_test.py Tests/kaas/k8s-node-distribution/check_nodes_test.py renamed to Tests/kaas/scs_0214_node_distribution_RETIRED/check_nodes_test.py

@@ -27,12 +27,10 @@ scripts:
     section: light
     description: Must fulfill all requirements of scs-0210-v2.
     url: https://docs.scs.community/standards/scs-0210-v2-k8s-version-policy#decision
-- executable: ./kaas/k8s-node-distribution/k8s_node_distribution_check.py
-  args: -k {kubeconfig}
-  testcases:
+- testcases:
   - id: node-distribution-check
-    section: light
-    description: Must fulfill all requirements of scs-0214-v2.
+    description: >-
+      Manual check: Must fulfill all requirements of scs-0214-v2.
     url: https://docs.scs.community/standards/scs-0214-v2-k8s-node-distribution#decision
 - executable: ./kaas/sonobuoy_handler/run_sonobuoy.py
   args: run -k {kubeconfig} --scs-sonobuoy-config kaas/scs-sonobuoy-config-v1.yaml -r {subject_root}/sono-results-0219 -c 'kaas-networking-check' -a '--e2e-focus "NetworkPolicy"' --execution-mode {execution_mode}
@@ -60,7 +58,7 @@ modules:
     name: Kubernetes node distribution and availability
     url: https://docs.scs.community/standards/scs-0214-v2-k8s-node-distribution
     targets:
-      main:
+      preview:
       - node-distribution-check
   - id: scs-0219-v1
     name: KaaS networking