Use a delegation model for configmap migration

This ensures only one observer impl is ever used at a time for etcd discovery

pkg/operator/configobservation/configobservercontroller/observe_config_controller.go

@@ -115,7 +115,7 @@ func NewConfigObserver(
 				// static path at which we expect to find the encryption config secret
 				"/etc/kubernetes/static-pod-resources/secrets/encryption-config/encryption-config",
 			),
-			etcdendpoints.ObserveStorageURLs,
+			etcdendpoints.BackwardsCompatibleObserveStorageURLs,
 			cloudprovider.NewCloudProviderObserver(
 				"openshift-kube-apiserver",
 				[]string{"apiServerArguments", "cloud-provider"},

pkg/operator/configobservation/etcdendpoints/observe_etcd_endpoints.go

@@ -12,14 +12,24 @@ import (
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 
 	"github.com/openshift/cluster-kube-apiserver-operator/pkg/operator/configobservation"
-	endpointobserver "github.com/openshift/cluster-kube-apiserver-operator/pkg/operator/configobservation/etcd"
+	endpointsobserver "github.com/openshift/cluster-kube-apiserver-operator/pkg/operator/configobservation/etcd"
 )
 
 const (
 	etcdEndpointNamespace = "openshift-etcd"
 	etcdEndpointName      = "etcd-endpoints"
 )
 
+func BackwardsCompatibleObserveStorageURLs(genericListers configobserver.Listers, recorder events.Recorder, currentConfig map[string]interface{}) (map[string]interface{}, []error) {
+	listers := genericListers.(configobservation.Listers)
+	if _, err := listers.ConfigmapLister.ConfigMaps(etcdEndpointNamespace).Get(etcdEndpointName); err == nil {
+		return ObserveStorageURLs(genericListers, recorder, currentConfig)
+	} else if !errors.IsNotFound(err) {
+		return nil, []error{err}
+	}
+	return endpointsobserver.ObserveStorageURLs(genericListers, recorder, currentConfig)
+}
+
 // ObserveStorageURLs observes the storage config URLs. If there is a problem observing the current storage config URLs,
 // then the previously observed storage config URLs will be re-used.
 func ObserveStorageURLs(genericListers configobserver.Listers, recorder events.Recorder, currentConfig map[string]interface{}) (map[string]interface{}, []error) {
@@ -42,20 +52,19 @@ func ObserveStorageURLs(genericListers configobserver.Listers, recorder events.R
 	etcdEndpoints, err := listers.ConfigmapLister.ConfigMaps(etcdEndpointNamespace).Get(etcdEndpointName)
 	if errors.IsNotFound(err) {
 		recorder.Warningf("ObserveStorageFailed", "Required %s/%s configmap not found", etcdEndpointNamespace, etcdEndpointName)
-
-		// Fall back to the old endpoint resource
-		return endpointobserver.ObserveStorageURLs(genericListers, recorder, currentConfig)
+		return previouslyObservedConfig, append(errs, fmt.Errorf("configmaps/%s.%s: not found", etcdEndpointName, etcdEndpointNamespace))
 	}
 	if err != nil {
-		recorder.Warningf("ObserveStorageFailed", "Error getting %s/%s endpoint: %v", etcdEndpointNamespace, etcdEndpointName, err)
+		recorder.Warningf("ObserveStorageFailed", "Error getting %s/%s configmap: %v", etcdEndpointNamespace, etcdEndpointName, err)
 		return previouslyObservedConfig, append(errs, err)
 	}
 
 	// note: etcd bootstrap should never be added to the in-cluster kube-apiserver
 	// this can result in some early pods crashlooping, but ensures that we never contact the bootstrap machine from
 	// the in-cluster kube-apiserver so we can safely teardown out of order.
 
-	for address := range etcdEndpoints.Data {
+	for k := range etcdEndpoints.Data {
+		address := etcdEndpoints.Data[k]
 		ip := net.ParseIP(address)
 		if ip == nil {
 			ipErr := fmt.Errorf("configmaps/%s in the %s namespace: %v is not a valid IP address", etcdEndpointName, etcdEndpointNamespace, address)
@@ -76,7 +85,7 @@ func ObserveStorageURLs(genericListers configobserver.Listers, recorder events.R
 	}
 
 	if len(etcdURLs) == 0 {
-		emptyURLErr := fmt.Errorf("endpoints %s/%s: no etcd endpoint addresses found", etcdEndpointNamespace, etcdEndpointName)
+		emptyURLErr := fmt.Errorf("configmaps %s/%s: no etcd endpoint addresses found", etcdEndpointNamespace, etcdEndpointName)
 		recorder.Warning("ObserveStorageFailed", emptyURLErr.Error())
 		errs = append(errs, emptyURLErr)
 	}

pkg/operator/configobservation/etcdendpoints/observe_etcd_endpoints_test.go

@@ -1,6 +1,7 @@
 package etcdendpoints
 
 import (
+	"encoding/base64"
 	"reflect"
 	"testing"
 
@@ -15,8 +16,6 @@ import (
 	"github.com/openshift/cluster-kube-apiserver-operator/pkg/operator/configobservation"
 )
 
-const clusterFQDN = "foo.bar"
-
 func TestObserveStorageURLs(t *testing.T) {
 	tests := []struct {
 		name          string
@@ -203,6 +202,6 @@ func withBootstrap(ip string) func(*v1.ConfigMap) {
 
 func withAddress(ip string) func(*v1.ConfigMap) {
 	return func(endpoints *v1.ConfigMap) {
-		endpoints.Data[ip] = ""
+		endpoints.Data[base64.StdEncoding.WithPadding(base64.NoPadding).EncodeToString([]byte(ip))] = ip
 	}
 }