fix: Allowlist deprecated features that are removed between k8s versions

Author: michaelasp

config/jobs/kubernetes/sig-testing/compatibility-versions-e2e.yaml

@@ -208,6 +208,10 @@ periodics:
       env:
       - name: RUNTIME_CONFIG
         value: '{"api/beta":"true", "api/ga":"true"}'
+      # List of features that are not in scope of emulation version and have been removed. These can pass since they are not subject to the same policies as
+      # feature gates that exist in components such as KCM.
+      - name: REMOVED_FEATURE_LIST
+        value: "LegacySidecarContainers"
       # we need privileged mode in order to do docker in docker
       securityContext:
         privileged: true
@@ -260,6 +264,10 @@ periodics:
         value: '{"api/beta":"true", "api/ga":"true"}'
       - name: VERSION_DELTA
         value: "2"
+      # List of features that are not in scope of emulation version and have been removed. These can pass since they are not subject to the same policies as
+      # feature gates that exist in components such as KCM.
+      - name: REMOVED_FEATURE_LIST
+        value: "LegacySidecarContainers"
       # we need privileged mode in order to do docker in docker
       securityContext:
         privileged: true

experiment/compatibility-versions/validate-compatibility-versions-feature-gates.sh

@@ -34,6 +34,9 @@ echo "Validating features for emulated_version=${emulated_version}, current_vers
 rm -f "${results_file}"
 touch "${results_file}"
 
+# Obtain the list of features that have been removed fully and are not in scope of emulation version(e.g kubelet)
+REMOVED_FEATURE_LIST=${REMOVED_FEATURE_LIST:-''}
+
 # Parse /metrics -> actual_features[featureName] = 0 or 1
 declare -A actual_features
 declare -A actual_stages
@@ -149,7 +152,7 @@ while IFS= read -r unversioned_feature_entry; do
 done < <(echo "$unversioned_feature_stream")
 
 # For each "expected" feature (versioned):
-# - If missing from /metrics => fail unless stage==ALPHA or lock==true
+# - If missing from /metrics => fail unless stage==ALPHA or lock==true or is a deprecated feature that is listed as properly removed.
 # - If present & stage!=ALPHA => compare numeric value
 for feature_name in "${!expected_stage[@]}"; do
   stage="${expected_stage[$feature_name]}"
@@ -168,6 +171,12 @@ for feature_name in "${!expected_stage[@]}"; do
       continue
     fi
 
+    # Deprecated feature that was removed, these can continue. These can only be features that are not in the 
+    # scope of compatibility version(e.g kuebelet).
+    if [[  "$REMOVED_FEATURE_LIST" == *"$feature_name"* ]]; then
+      continue
+    fi
+
     echo "FAIL: expected feature gate '$feature_name' not found in metrics (stage=${stage}, lockToDefault=${locked})" \
     >> "${results_file}"
     continue
@@ -198,6 +207,11 @@ for unversioned_feature_name in "${!expected_unversioned_stage[@]}"; do
     if [[ "$unversioned_locked" == "true" ]]; then
       continue
     fi
+    # Deprecated feature that was removed, these can continue. These can only be features that are not in the 
+    # scope of compatibility version(e.g kuebelet).
+    if [[  "$REMOVED_FEATURE_LIST" == *"$feature_name"* ]]; then
+      continue
+    fi
     echo "FAIL: expected unversioned feature gate '$unversioned_feature_name' not found in metrics (lockToDefault=${unversioned_locked})" \
     >> "${results_file}"
     continue