Drain OpenStack loadbalancers

Author: zetaab

cloudmock/gce/mock_gce_cloud.go

@@ -181,6 +181,10 @@ func (c *MockGCECloud) DeleteInstance(i *cloudinstances.CloudInstance) error {
 	//	return recreateCloudInstance(c, i)
 }
 
+func (c *MockGCECloud) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	return nil
+}
+
 // DetachInstance is not implemented yet. It needs to cause a cloud instance to no longer be counted against the group's size limits.
 func (c *MockGCECloud) DetachInstance(i *cloudinstances.CloudInstance) error {
 	return nil

pkg/instancegroups/instancegroups.go

@@ -646,6 +646,10 @@ func (c *RollingUpdateCluster) drainNode(u *cloudinstances.CloudInstance) error
 		return fmt.Errorf("error excluding node from load balancer: %v", err)
 	}
 
+	if err := c.Cloud.DeregisterInstance(u); err != nil {
+		return fmt.Errorf("error deregistering instance %q, node %q: %v", u.ID, u.Node.Name, err)
+	}
+
 	if err := drain.RunNodeDrain(helper, u.Node.Name); err != nil {
 		if apierrors.IsNotFound(err) {
 			return nil

pkg/kubeconfig/create_kubecfg_test.go

@@ -74,6 +74,10 @@ func (f fakeStatusCloud) DetachInstance(instance *cloudinstances.CloudInstance)
 	panic("not implemented")
 }
 
+func (f fakeStatusCloud) DeregisterInstance(instance *cloudinstances.CloudInstance) error {
+	panic("not implemented")
+}
+
 func (f fakeStatusCloud) GetCloudGroups(cluster *kops.Cluster, instancegroups []*kops.InstanceGroup, warnUnmatched bool, nodes []v1.Node) (map[string]*cloudinstances.CloudInstanceGroup, error) {
 	panic("not implemented")
 }

pkg/model/openstackmodel/servergroup.go

@@ -329,6 +329,7 @@ func (b *ServerGroupModelBuilder) Build(c *fi.ModelBuilderContext) error {
 				InterfaceName: fi.String(ifName),
 				ProtocolPort:  fi.Int(443),
 				Lifecycle:     b.Lifecycle,
+				Weight:        fi.Int(1),
 			}
 
 			c.AddTask(associateTask)

pkg/model/openstackmodel/tests/servergroup/multizone-setup-3-masters-3-nodes-without-bastion-with-API-loadbalancer.yaml

@@ -769,6 +769,7 @@ ServerGroup:
   Name: cluster-master-a
   Policies:
   - anti-affinity
+Weight: 1
 ---
 ID: null
 InterfaceName: cluster
@@ -802,6 +803,7 @@ ServerGroup:
   Name: cluster-master-b
   Policies:
   - anti-affinity
+Weight: 1
 ---
 ID: null
 InterfaceName: cluster
@@ -835,6 +837,7 @@ ServerGroup:
   Name: cluster-master-c
   Policies:
   - anti-affinity
+Weight: 1
 ---
 AdditionalSecurityGroups: null
 ID: null

upup/pkg/fi/cloud.go

@@ -33,6 +33,9 @@ type Cloud interface {
 	// DeleteInstance deletes a cloud instance.
 	DeleteInstance(instance *cloudinstances.CloudInstance) error
 
+	// // DeregisterInstance drains a cloud instance and loadbalancers.
+	DeregisterInstance(instance *cloudinstances.CloudInstance) error
+
 	// DeleteGroup deletes the cloud resources that make up a CloudInstanceGroup, including the instances.
 	DeleteGroup(group *cloudinstances.CloudInstanceGroup) error
 

upup/pkg/fi/cloudup/awsup/aws_cloud.go

@@ -541,6 +541,12 @@ func (c *awsCloudImplementation) DeleteInstance(i *cloudinstances.CloudInstance)
 	return deleteInstance(c, i)
 }
 
+// DeregisterInstance drains a cloud instance and loadbalancers.
+func (c *awsCloudImplementation) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	klog.V(8).Info("AWS DeregisterInstance not implemented")
+	return nil
+}
+
 func deleteInstance(c AWSCloud, i *cloudinstances.CloudInstance) error {
 	id := i.ID
 	if id == "" {

upup/pkg/fi/cloudup/awsup/mock_aws_cloud.go

@@ -96,6 +96,10 @@ func (c *MockAWSCloud) DeleteInstance(i *cloudinstances.CloudInstance) error {
 	return deleteInstance(c, i)
 }
 
+func (c *MockAWSCloud) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	return nil
+}
+
 func (c *MockAWSCloud) DetachInstance(i *cloudinstances.CloudInstance) error {
 	return detachInstance(c, i)
 }

upup/pkg/fi/cloudup/azure/azure_cloud.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 
 	"github.com/Azure/go-autorest/autorest/azure/auth"
+	"k8s.io/klog/v2"
 	"k8s.io/kops/dnsprovider/pkg/dnsprovider"
 	"k8s.io/kops/pkg/apis/kops"
 	"k8s.io/kops/pkg/cloudinstances"
@@ -144,6 +145,12 @@ func (c *azureCloudImplementation) DeleteInstance(i *cloudinstances.CloudInstanc
 	return errors.New("DeleteInstance not implemented on azureCloud")
 }
 
+// DeregisterInstance drains a cloud instance and loadbalancers.
+func (c *azureCloudImplementation) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	klog.V(8).Info("Azure DeregisterInstance not implemented")
+	return nil
+}
+
 func (c *azureCloudImplementation) DeleteGroup(g *cloudinstances.CloudInstanceGroup) error {
 	return errors.New("DeleteGroup not implemented on azureCloud")
 }

upup/pkg/fi/cloudup/azuretasks/testing.go

@@ -131,6 +131,10 @@ func (c *MockAzureCloud) DeleteInstance(i *cloudinstances.CloudInstance) error {
 	return errors.New("DeleteInstance not implemented on azureCloud")
 }
 
+func (c *MockAzureCloud) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	return nil
+}
+
 // DeleteGroup deletes the group.
 func (c *MockAzureCloud) DeleteGroup(g *cloudinstances.CloudInstanceGroup) error {
 	return errors.New("DeleteGroup not implemented on azureCloud")

upup/pkg/fi/cloudup/do/cloud.go

@@ -136,6 +136,12 @@ func (c *doCloudImplementation) DeleteGroup(g *cloudinstances.CloudInstanceGroup
 	return fmt.Errorf("digital ocean cloud provider does not support deleting cloud groups at this time")
 }
 
+// DeregisterInstance drains a cloud instance and loadbalancers.
+func (c *doCloudImplementation) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	klog.V(8).Info("DO DeregisterInstance not implemented")
+	return nil
+}
+
 func (c *doCloudImplementation) DeleteInstance(i *cloudinstances.CloudInstance) error {
 	dropletID, err := strconv.Atoi(i.ID)
 	if err != nil {

upup/pkg/fi/cloudup/do/mock_do_cloud.go

@@ -69,6 +69,10 @@ func (c *doCloudMockImplementation) DeleteInstance(instance *cloudinstances.Clou
 	return errors.New("not tested")
 }
 
+func (c *doCloudMockImplementation) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	return nil
+}
+
 // DetachInstance is not implemented yet. It needs to cause a cloud instance to no longer be counted against the group's size limits.
 func (c *doCloudMockImplementation) DetachInstance(i *cloudinstances.CloudInstance) error {
 	return fmt.Errorf("digital ocean cloud provider does not support surging")

upup/pkg/fi/cloudup/gce/instancegroups.go

@@ -51,6 +51,11 @@ func (c *gceCloudImplementation) DeleteInstance(i *cloudinstances.CloudInstance)
 	return recreateCloudInstance(c, i)
 }
 
+func (c *gceCloudImplementation) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	klog.V(8).Info("GCE DeregisterInstance not implemented")
+	return nil
+}
+
 // DetachInstance is not implemented yet. It needs to cause a cloud instance to no longer be counted against the group's size limits.
 func (c *gceCloudImplementation) DetachInstance(i *cloudinstances.CloudInstance) error {
 	klog.V(8).Info("gce cloud provider DetachInstance not implemented yet")

upup/pkg/fi/cloudup/openstack/BUILD.bazel

@@ -252,8 +252,11 @@ type OpenstackCloud interface {
 	// ListDNSRecordsets will list the DNS recordsets for the given zone id
 	ListDNSRecordsets(zoneID string, opt recordsets.ListOptsBuilder) ([]recordsets.RecordSet, error)
 	GetLB(loadbalancerID string) (*loadbalancers.LoadBalancer, error)
+	GetLBStats(loadbalancerID string) (*loadbalancers.Stats, error)
 	CreateLB(opt loadbalancers.CreateOptsBuilder) (*loadbalancers.LoadBalancer, error)
 	ListLBs(opt loadbalancers.ListOptsBuilder) ([]loadbalancers.LoadBalancer, error)
+	UpdateMemberInPool(poolID string, memberID string, opts v2pools.UpdateMemberOptsBuilder) (*v2pools.Member, error)
+	ListPoolMembers(poolID string, opts v2pools.ListMembersOpts) ([]v2pools.Member, error)
 
 	// DeleteLB will delete loadbalancer
 	DeleteLB(lbID string, opt loadbalancers.DeleteOpts) error

upup/pkg/fi/cloudup/openstack/cloud.go

@@ -17,15 +17,19 @@ limitations under the License.
 package openstack
 
 import (
+	"context"
 	"fmt"
 	"time"
 
 	"github.com/gophercloud/gophercloud/openstack/compute/v2/flavors"
 
 	"github.com/gophercloud/gophercloud"
 	"github.com/gophercloud/gophercloud/openstack/compute/v2/servers"
+	"github.com/gophercloud/gophercloud/openstack/loadbalancer/v2/loadbalancers"
+	v2pools "github.com/gophercloud/gophercloud/openstack/loadbalancer/v2/pools"
 	"github.com/gophercloud/gophercloud/openstack/networking/v2/ports"
 	"github.com/mitchellh/mapstructure"
+	"golang.org/x/sync/errgroup"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/klog/v2"
 	"k8s.io/kops/pkg/cloudinstances"
@@ -170,6 +174,99 @@ func deleteInstanceWithID(c OpenstackCloud, instanceID string) error {
 	}
 }
 
+// DeregisterInstance drains a cloud instance and loadbalancers.
+func (c *openstackCloud) DeregisterInstance(i *cloudinstances.CloudInstance) error {
+	return deregisterInstance(c, i.ID)
+}
+
+// deregisterInstance will drain all the loadbalancers attached to instance
+func deregisterInstance(c OpenstackCloud, instanceID string) error {
+	instance, err := c.GetInstance(instanceID)
+	if err != nil {
+		return err
+	}
+
+	// Kubernetes creates loadbalancers that member name matches to instance name
+	// However, kOps uses different name format in API LB which is <cluster>-<ig>
+	instanceName := instance.Name
+	kopsName := ""
+	ig, igok := instance.Metadata[TagKopsInstanceGroup]
+	clusterName, clusterok := instance.Metadata[TagClusterName]
+	if igok && clusterok {
+		kopsName = fmt.Sprintf("%s-%s", clusterName, ig)
+	}
+
+	lbs, err := c.ListLBs(loadbalancers.ListOpts{})
+	if err != nil {
+		return err
+	}
+	ctx := context.Background()
+	eg, _ := errgroup.WithContext(ctx)
+	for i := range lbs {
+		func(lb loadbalancers.LoadBalancer) {
+			eg.Go(func() error {
+				return drainSingleLB(c, lb, instanceName, kopsName)
+			})
+		}(lbs[i])
+	}
+
+	if err := eg.Wait(); err != nil {
+		return fmt.Errorf("failed to deregister instance from load balancers: %v", err)
+	}
+
+	return nil
+}
+
+// drainSingleLB will drain single loadbalancer that is attached to instance
+func drainSingleLB(c OpenstackCloud, lb loadbalancers.LoadBalancer, instanceName string, kopsName string) error {
+	oldStats, err := c.GetLBStats(lb.ID)
+	if err != nil {
+		return err
+	}
+
+	draining := false
+	pools, err := c.ListPools(v2pools.ListOpts{
+		LoadbalancerID: lb.ID,
+	})
+	if err != nil {
+		return err
+	}
+	for _, pool := range pools {
+		members, err := c.ListPoolMembers(pool.ID, v2pools.ListMembersOpts{})
+		if err != nil {
+			return err
+		}
+		for _, member := range members {
+			if member.Name == instanceName || (member.Name == kopsName && len(kopsName) > 0) {
+				// https://docs.openstack.org/api-ref/load-balancer/v2/?expanded=update-a-member-detail
+				// Setting the member weight to 0 means that the member will not receive new requests but will finish any existing connections.
+				// This “drains” the backend member of active connections.
+				_, err := c.UpdateMemberInPool(pool.ID, member.ID, v2pools.UpdateMemberOpts{
+					Weight: fi.Int(0),
+				})
+				if err != nil {
+					return err
+				}
+				draining = true
+				break
+			}
+		}
+	}
+
+	if draining {
+		// TODO: should we do somekind of loop here and check that connections are really drained?
+		time.Sleep(20 * time.Second)
+
+		newStats, err := c.GetLBStats(lb.ID)
+		if err != nil {
+			return err
+		}
+
+		klog.Infof("Loadbalancer %s connections before draining %d and after %d", lb.Name, oldStats.ActiveConnections, newStats.ActiveConnections)
+	}
+	return nil
+}
+
 // DetachInstance is not implemented yet. It needs to cause a cloud instance to no longer be counted against the group's size limits.
 func (c *openstackCloud) DetachInstance(i *cloudinstances.CloudInstance) error {
 	return detachInstance(c, i)