configobserver: add minimumkubeletversion

Signed-off-by: Peter Hunt <[email protected]>

pkg/operator/configobservation/configobservercontroller/observe_config_controller.go

@@ -157,6 +157,7 @@ func NewConfigObserver(operatorClient v1helpers.StaticPodOperatorClient, kubeInf
 					),
 				},
 			),
+			node.NewMinimumKubeletVersionObserver(featureGateAccessor),
 			proxy.NewProxyObserveFunc([]string{"targetconfigcontroller", "proxy"}),
 			images.ObserveInternalRegistryHostname,
 			images.ObserveExternalRegistryHostnames,

pkg/operator/configobservation/node/listers.go

@@ -0,0 +1,9 @@
+package node
+
+import (
+	configlistersv1 "github.com/openshift/client-go/config/listers/config/v1"
+)
+
+type NodeLister interface {
+	NodeLister() configlistersv1.NodeLister
+}

pkg/operator/configobservation/node/listers_test.go

@@ -0,0 +1,24 @@
+package node
+
+import (
+	"k8s.io/client-go/tools/cache"
+
+	configlistersv1 "github.com/openshift/client-go/config/listers/config/v1"
+	"github.com/openshift/library-go/pkg/operator/resourcesynccontroller"
+)
+
+type testLister struct {
+	nodeLister configlistersv1.NodeLister
+}
+
+func (l testLister) NodeLister() configlistersv1.NodeLister {
+	return l.nodeLister
+}
+
+func (l testLister) ResourceSyncer() resourcesynccontroller.ResourceSyncer {
+	return nil
+}
+
+func (l testLister) PreRunHasSynced() []cache.InformerSynced {
+	return nil
+}

pkg/operator/configobservation/node/observe_minimum_kubelet_version.go

@@ -0,0 +1,73 @@
+package node
+
+import (
+	configv1 "github.com/openshift/api/config/v1"
+	"github.com/openshift/api/features"
+	"github.com/openshift/library-go/pkg/operator/configobserver"
+	"github.com/openshift/library-go/pkg/operator/configobserver/featuregates"
+	"github.com/openshift/library-go/pkg/operator/events"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/klog/v2"
+)
+
+var minimumKubeletVersionConfigPath = "minimumKubeletVersion"
+
+type minimumKubeletVersionObserver struct {
+	featureGateAccessor featuregates.FeatureGateAccess
+}
+
+func NewMinimumKubeletVersionObserver(featureGateAccessor featuregates.FeatureGateAccess) configobserver.ObserveConfigFunc {
+	return (&minimumKubeletVersionObserver{
+		featureGateAccessor: featureGateAccessor,
+	}).ObserveMinimumKubeletVersion
+}
+
+// ObserveKubeletMinimumVersion watches the node configuration and generates the minimumKubeletVersion
+func (o *minimumKubeletVersionObserver) ObserveMinimumKubeletVersion(genericListers configobserver.Listers, _ events.Recorder, existingConfig map[string]interface{}) (ret map[string]interface{}, errs []error) {
+	if !o.featureGateAccessor.AreInitialFeatureGatesObserved() {
+		// if we haven't observed featuregates yet, return the existing
+		return existingConfig, nil
+	}
+
+	featureGates, err := o.featureGateAccessor.CurrentFeatureGates()
+	if err != nil {
+		return existingConfig, append(errs, err)
+	}
+
+	if !featureGates.Enabled(features.FeatureGateMinimumKubeletVersion) {
+		return existingConfig, nil
+	}
+
+	defer func() {
+		// Prune the observed config so that it only contains minimumKubeletVersion field.
+		ret = configobserver.Pruned(ret, []string{minimumKubeletVersionConfigPath})
+	}()
+	nodeLister := genericListers.(NodeLister)
+	configNode, err := nodeLister.NodeLister().Get("cluster")
+	// we got an error so without the node object we are not able to determine minimumKubeletVersion
+	if err != nil {
+		// if config/v1/node/cluster object is not found, that can be treated as a non-error case, but raise a warning
+		if apierrors.IsNotFound(err) {
+			klog.Warningf("ObserveMinimumKubeletVersion: nodes.%s/cluster not found", configv1.GroupName)
+		} else {
+			errs = append(errs, err)
+		}
+		return existingConfig, errs
+	}
+
+	if configNode.Spec.MinimumKubeletVersion == "" {
+		// in case minimum kubelet version is not set on cluster
+		// return empty set of configs, this helps to unset the config
+		// values related to the minimumKubeletVersion.
+		// Also, ensures that this observer doesn't break cluster upgrades/downgrades
+		return map[string]interface{}{}, errs
+	}
+
+	ret = map[string]interface{}{}
+	if err := unstructured.SetNestedField(ret, configNode.Spec.MinimumKubeletVersion, minimumKubeletVersionConfigPath); err != nil {
+		errs = append(errs, err)
+	}
+
+	return ret, errs
+}

pkg/operator/configobservation/node/observe_minimum_kubelet_version_test.go

@@ -0,0 +1,99 @@
+package node
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	configv1 "github.com/openshift/api/config/v1"
+	"github.com/openshift/api/features"
+	configlistersv1 "github.com/openshift/client-go/config/listers/config/v1"
+	"github.com/openshift/library-go/pkg/operator/configobserver/featuregates"
+	"github.com/openshift/library-go/pkg/operator/events"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/tools/cache"
+	clocktesting "k8s.io/utils/clock/testing"
+)
+
+func TestObserveKubeletMinimumVersion(t *testing.T) {
+	type Test struct {
+		name                   string
+		existingConfig         map[string]interface{}
+		expectedObservedConfig map[string]interface{}
+		minimumKubeletVersion  string
+		featureOn              bool
+	}
+	tests := []Test{
+		{
+			name:                   "feature off",
+			existingConfig:         map[string]interface{}{},
+			expectedObservedConfig: map[string]interface{}{},
+			minimumKubeletVersion:  "1.30.0",
+			featureOn:              false,
+		},
+		{
+			name:                   "empty minimumKubeletVersion",
+			expectedObservedConfig: map[string]interface{}{},
+			minimumKubeletVersion:  "",
+			featureOn:              true,
+		},
+		{
+			name: "set minimumKubeletVersion",
+			expectedObservedConfig: map[string]interface{}{
+				"minimumKubeletVersion": string("1.30.0"),
+			},
+			minimumKubeletVersion: "1.30.0",
+			featureOn:             true,
+		},
+		{
+			name: "existing minimumKubeletVersion",
+			expectedObservedConfig: map[string]interface{}{
+				"minimumKubeletVersion": string("1.30.0"),
+			},
+			existingConfig: map[string]interface{}{
+				"minimumKubeletVersion": string("1.29.0"),
+			},
+			minimumKubeletVersion: "1.30.0",
+			featureOn:             true,
+		},
+		{
+			name:                   "existing minimumKubeletVersion unset",
+			expectedObservedConfig: map[string]interface{}{},
+			existingConfig: map[string]interface{}{
+				"minimumKubeletVersion": string("1.29.0"),
+			},
+			minimumKubeletVersion: "",
+			featureOn:             true,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			// test data
+			eventRecorder := events.NewInMemoryRecorder("", clocktesting.NewFakePassiveClock(time.Now()))
+			configNodeIndexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{})
+			configNodeIndexer.Add(&configv1.Node{
+				ObjectMeta: metav1.ObjectMeta{Name: "cluster"},
+				Spec:       configv1.NodeSpec{MinimumKubeletVersion: test.minimumKubeletVersion},
+			})
+			listers := testLister{
+				nodeLister: configlistersv1.NewNodeLister(configNodeIndexer),
+			}
+
+			fg := featuregates.NewHardcodedFeatureGateAccess([]configv1.FeatureGateName{features.FeatureGateMinimumKubeletVersion}, []configv1.FeatureGateName{})
+			if !test.featureOn {
+				fg = featuregates.NewHardcodedFeatureGateAccess([]configv1.FeatureGateName{}, []configv1.FeatureGateName{features.FeatureGateMinimumKubeletVersion})
+			}
+
+			// act
+			actualObservedConfig, errs := NewMinimumKubeletVersionObserver(fg)(listers, eventRecorder, test.existingConfig)
+
+			// validate
+			if len(errs) > 0 {
+				t.Fatal(errs)
+			}
+			if diff := cmp.Diff(test.expectedObservedConfig, actualObservedConfig); diff != "" {
+				t.Fatalf("unexpected configuration, diff = %v", diff)
+			}
+		})
+	}
+}