Provide --cluster-name flag to the OpenStack external CCM

Signed-off-by: Marko Mudrinić <mudrinic.mare@gmail.com>

addons/ccm-openstack/ccm-openstack.yaml

@@ -192,6 +192,9 @@ spec:
             - --cloud-provider=openstack
             - --use-service-account-credentials=true
             - --bind-address=127.0.0.1
+            {{ if .CCMClusterName }}
+            - --cluster-name={{ .CCMClusterName }}
+            {{ end }}
 {{ if .Config.CABundle }}
           env:
 {{ caBundleEnvVar | indent 12 }}

pkg/addons/applier.go

@@ -58,6 +58,7 @@ type templateData struct {
 	Config                              *kubeoneapi.KubeOneCluster
 	Certificates                        map[string]string
 	Credentials                         map[string]string
+	CCMClusterName                      string
 	CSIMigration                        bool
 	CSIMigrationFeatureGates            string
 	MachineControllerCredentialsEnvVars string
@@ -155,6 +156,7 @@ func newAddonsApplier(s *state.State) (*applier, error) {
 			"KubernetesCA":                 mcCertsMap[resources.KubernetesCACertName],
 		},
 		Credentials:                         creds,
+		CCMClusterName:                      s.LiveCluster.CCMClusterName,
 		CSIMigration:                        csiMigration,
 		CSIMigrationFeatureGates:            csiMigrationFeatureGates,
 		MachineControllerCredentialsEnvVars: string(credsEnvVars),

pkg/state/cluster.go

@@ -35,6 +35,7 @@ type Cluster struct {
 	StaticWorkers           []Host
 	ExpectedVersion         *semver.Version
 	EncryptionConfiguration *EncryptionConfiguration
+	CCMClusterName          string
 	CCMStatus               *CCMStatus
 	Lock                    sync.Mutex
 }

pkg/tasks/probes.go

@@ -183,6 +183,14 @@ func runProbes(s *state.State) error {
 		s.Cluster.ContainerRuntime.Docker = &kubeoneapi.ContainerRuntimeDocker{}
 	}
 
+	clusterName, cnErr := detectClusterName(s)
+	if cnErr != nil {
+		return errors.Wrap(cnErr, "failed to detect the name of OpenStack cluster")
+	}
+	s.LiveCluster.Lock.Lock()
+	s.LiveCluster.CCMClusterName = clusterName
+	s.LiveCluster.Lock.Unlock()
+
 	return nil
 }
 
@@ -636,3 +644,74 @@ func detectCCMMigrationStatus(s *state.State) (*state.CCMStatus, error) {
 
 	return status, nil
 }
+
+// detectClusterName is used to detect the value that should be passed to the
+// external CCM via the --cluster-name flag.
+//
+// This function is currently used for OpenStack clusters, because we initially
+// didn't set this flag, in which case it defaults to `kubernetes`.
+//
+// Not setting the flag can cause issues if there are multiple clusters in the
+// same tenant. For example, Load Balancers with the same name in different
+// clusters will share the same Octavia LB.
+//
+// Changing the --cluster-name causes the CCM to lose all references to the
+// Load Balancers on OpenStack, because the cluster name is used as part of
+// the reference to the LB. Therefore, we need this function to ensure the
+// backwards compatibility.
+//
+// The function works in the following way:
+//   * if the cluster is not provisioned, or if the cluster is not an OpenStack
+//     cluster, return the KubeOne cluster name
+//   * if it's an existing OpenStack cluster:
+//      * if cluster is running in-tree cloud provider: return the KubeOne
+//        cluster name because the in-tree provider already has the
+//        --cluster-name flag set
+//      * if cluster is running external cloud provider: check if there is
+//        `--cluster-name` flag on the OpenStack CCM. If there is, read the
+//        value and return it, otherwise don't set the OpenStack cluster name,
+//        in which case it defaults to `kubernetes`
+//   * if cluster is migrated to external CCM, return the KubeOne cluster name
+//
+// If an operator wants to change the --cluster-name flag on OpenStack external
+// CCM, they need to edit the CCM DaemonSet manually. KubeOne will
+// automatically pick up the provided value when reconciling the cluster.
+func detectClusterName(s *state.State) (string, error) {
+	if !s.LiveCluster.IsProvisioned() ||
+		s.LiveCluster.CCMStatus == nil ||
+		s.Cluster.CloudProvider.Openstack == nil {
+		return s.Cluster.Name, nil
+	}
+
+	if s.LiveCluster.CCMStatus.InTreeCloudProviderEnabled && !s.LiveCluster.CCMStatus.ExternalCCMDeployed {
+		return s.Cluster.Name, nil
+	}
+
+	pods := corev1.PodList{}
+	err := s.DynamicClient.List(s.Context, &pods, &dynclient.ListOptions{
+		Namespace: metav1.NamespaceSystem,
+		LabelSelector: labels.SelectorFromSet(map[string]string{
+			k8sAppLabel: "openstack-cloud-controller-manager",
+		}),
+	})
+	if err != nil {
+		return "", err
+	}
+	if len(pods.Items) == 0 || len(pods.Items[0].Spec.Containers) == 0 {
+		return "", errors.New("unable to detect OpenStack CCM pod/container")
+	}
+	for _, container := range pods.Items[0].Spec.Containers {
+		if container.Name != "openstack-cloud-controller-manager" {
+			continue
+		}
+		for _, flag := range container.Command {
+			if strings.HasPrefix(flag, "--cluster-name") {
+				return strings.Split(flag, "=")[1], nil
+			}
+		}
+	}
+
+	// If we got here, the cluster is running external CCM, but we didn't
+	// find the --cluster-name flag, therefore assume default value.
+	return "", nil
+}