support config lb backend nodes count for service;

Signed-off-by: gangqiangwang <gangqiangwang@yunify.com>;

docs/configure.md

@@ -155,7 +155,13 @@ spec:
   - `Cluster`: 如果`service`中不显式指定 `externalTrafficPolicy` 字段的值，则默认为`Cluster`；这种模式下，可以通过给服务添加相关注解来指定LB监听器backend的添加规则
 
 `Cluster`模式下，目前支持的 `service` 注解有：
-- 使用指定Label的Worker节点作为后端服务器， `service.beta.kubernetes.io/qingcloud-lb-backend-label`，可以指定多个Label，多个Label以逗号分隔。例如：`key1=value1,key2=value2`，多个Label之间是And关系。同时，在需要成为后端服务器的Worker节点打上`key1=value1,key2=value2`的Label；只有服务指定的所有Label的key和value都和Worker节点匹配时，Worker节点会被选为服务的后端服务器；没有此注解则添加所有Worker节点为backend；通过注解过滤节点后，如果没有满足条件的节点，为了避免服务中断，会添加所有Worker节点为后端服务器；
+> 以下各种过滤节点的方式不能结合使用，如果指定了多个，则会按照以下注解的说明顺序选用第一个匹配到的注解，并按照该方法过滤节点；
+- 使用指定Label的Worker节点作为后端服务器， `service.beta.kubernetes.io/qingcloud-lb-backend-label`，可以指定多个Label，多个Label以逗号分隔。例如：`key1=value1,key2=value2`，多个Label之间是And关系。同时，在需要成为后端服务器的Worker节点打上`key1=value1,key2=value2`的Label；只有服务指定的所有Label的key和value都和Worker节点匹配时，Worker节点会被选为服务的后端服务器；特殊情况说明：
+  - 没有此注解则添加所有Worker节点为backend；
+  - 通过注解过滤节点后，如果没有满足条件的节点，为了避免服务中断，会添加所有Worker节点为后端服务器；
+- 使用指定数量的Worker节点作为后端服务器，`service.beta.kubernetes.io/qingcloud-lb-backend-count`，通过此注解指定该服务使用的lb backend节点数量；如果服务添加了该注解，就认为用户想使用该特性；如果指定的数量为0或者不在可用节点数量的范围内，则使用默认值：集群所有节点的1/3；如果集群中节点状态发生变化，但是当前服务的lb后端数量就是用户指定的数量，并且已添加的所有lb后端节点在集群中都是ready状态的，则不会更新lb的backend；默认值特殊情况说明：
+  - 如果集群总worker节点数少于3个，则添加所有worker节点为backend，不再按照比例计算节点数；
+  - 如果集群总worker节点数多于3个，若按照比例计算后少于3个，则设置为3个;
 
 > 本章节所说的"所有Worker节点"特指所有 `Ready` 状态的Worker节点；
 
@@ -184,6 +190,7 @@ spec:
 ```
 
 #### Cluster模式
+##### 使用指定Label的Worker节点作为后端服务器
 将服务的`externalTrafficPolicy`指定为`Cluster`，并在服务的注解`service.beta.kubernetes.io/qingcloud-lb-backend-label`中指定要添加为backend的worker节点的label:
 
 ```yaml
@@ -232,6 +239,28 @@ status:
   ...
 ```
 
+##### 使用指定数量的Worker节点作为后端服务器
+
+```yaml
+kind: Service
+apiVersion: v1
+metadata:
+  name:  reuse-lb
+  annotations:
+    service.beta.kubernetes.io/qingcloud-load-balancer-eip-strategy: "reuse-lb"
+    service.beta.kubernetes.io/qingcloud-load-balancer-id: "lb-oglqftju"
+    service.beta.kubernetes.io/qingcloud-lb-backend-count: "3"
+spec:
+  externalTrafficPolicy: Cluster
+  selector:
+    app:  mylbapp
+  type:  LoadBalancer
+  ports:
+  - name:  http
+    port:  8090
+    protocol: TCP
+    targetPort:  80
+```
 
 ## 配置内网负载均衡器
 ### 已知问题

pkg/qingcloud/annotations.go

@@ -80,10 +80,14 @@ const (
 	ServiceAnnotationListenerServerCertificate = "service.beta.kubernetes.io/qingcloud-lb-listener-cert"
 	// port:protocol, such as "443:https,80:http"
 	ServiceAnnotationListenerProtocol = "service.beta.kubernetes.io/qingcloud-lb-listener-protocol"
+	// port:timeout, such as "443:50", the value must in range 10 ～ 86400
+	ServiceAnnotationListenerTimeout = "service.beta.kubernetes.io/qingcloud-lb-listener-timeout"
 
 	// 5. Configure backend
 	// backend label, such as "key1=value1,key2=value2"
 	ServiceAnnotationBackendLabel = "service.beta.kubernetes.io/qingcloud-lb-backend-label"
+	// backend count limit, if value is 0 or greater than cluster ready worker, will use default value : 1/3 of cluster ready worker
+	ServiceAnnotationBackendCount = "service.beta.kubernetes.io/qingcloud-lb-backend-count"
 )
 
 type LoadBalancerConfig struct {
@@ -105,7 +109,9 @@ type LoadBalancerConfig struct {
 	Protocol           *string
 
 	//backend
-	BackendLabel string
+	BackendLabel       string
+	BackendCountConfig string
+	BackendCountResult int
 
 	//It's just for defining names, nothing more.
 	NetworkType      string
@@ -171,6 +177,13 @@ func (qc *QingCloud) ParseServiceLBConfig(cluster string, service *v1.Service) (
 	if backendLabel, ok := annotation[ServiceAnnotationBackendLabel]; ok {
 		config.BackendLabel = backendLabel
 	}
+	if backendCount, ok := annotation[ServiceAnnotationBackendCount]; ok {
+		_, err := strconv.Atoi(backendCount)
+		if err != nil {
+			return nil, fmt.Errorf("please spec a valid value of loadBalancer backend count")
+		}
+		config.BackendCountConfig = backendCount
+	}
 
 	networkType := annotation[ServiceAnnotationLoadBalancerNetworkType]
 	if config.VxNetID == nil && qc.Config.DefaultVxNetForLB != "" {

pkg/qingcloud/loadbalancer_test.go

@@ -400,7 +400,7 @@ func TestDiffListeners(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		toDelete, toAdd := diffListeners(tc.listeners, tc.conf, tc.ports)
+		toDelete, toAdd, _ := diffListeners(tc.listeners, tc.conf, tc.ports)
 		// fmt.Printf("delete=%s, add=%s", spew.Sdump(toDelete), spew.Sdump(toAdd))
 		if !reflect.DeepEqual(toDelete, tc.toDelete) || !reflect.DeepEqual(toAdd, tc.toAdd) {
 			t.Fail()

pkg/qingcloud/loadbalancer_utils.go

@@ -1,7 +1,9 @@
 package qingcloud
 
 import (
+	"crypto/rand"
 	"fmt"
+	"math/big"
 	"strconv"
 	"strings"
 
@@ -152,7 +154,7 @@ func getProtocol(annotationConf map[int]string, port int) *string {
 	}
 }
 
-func diffListeners(listeners []*apis.LoadBalancerListener, conf *LoadBalancerConfig, ports []v1.ServicePort) (toDelete []*string, toAdd []v1.ServicePort) {
+func diffListeners(listeners []*apis.LoadBalancerListener, conf *LoadBalancerConfig, ports []v1.ServicePort) (toDelete []*string, toAdd []v1.ServicePort, toKeep []*apis.LoadBalancerListener) {
 	svcNodePort := make(map[string]int)
 	for _, listener := range listeners {
 		if len(listener.Status.LoadBalancerBackends) > 0 {
@@ -197,6 +199,8 @@ func diffListeners(listeners []*apis.LoadBalancerListener, conf *LoadBalancerCon
 		}
 		if delete {
 			toDelete = append(toDelete, listener.Status.LoadBalancerListenerID)
+		} else {
+			toKeep = append(toKeep, listener)
 		}
 	}
 
@@ -521,3 +525,18 @@ func equalProtocol(listener *apis.LoadBalancerListener, conf *LoadBalancerConfig
 	}
 	return false
 }
+
+func getRandomNodes(nodes []*v1.Node, count int) (result []*v1.Node) {
+	resultMap := make(map[int64]bool)
+	length := int64(len(nodes))
+
+	for i := 0; i < count; {
+		r, _ := rand.Int(rand.Reader, big.NewInt(length))
+		if !resultMap[r.Int64()] {
+			result = append(result, nodes[r.Int64()])
+			resultMap[r.Int64()] = true
+			i++
+		}
+	}
+	return
+}

pkg/qingcloud/qingcloud.go

@@ -11,6 +11,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"strconv"
 
 	"github.com/davecgh/go-spew/spew"
 	yaml "gopkg.in/yaml.v2"
@@ -27,8 +28,9 @@ import (
 )
 
 const (
-	ProviderName = "qingcloud"
-	QYConfigPath = "/etc/qingcloud/config.yaml"
+	ProviderName        = "qingcloud"
+	QYConfigPath        = "/etc/qingcloud/config.yaml"
+	DefaultBackendCount = 3
 )
 
 type Config struct {
@@ -232,7 +234,7 @@ func (qc *QingCloud) EnsureLoadBalancer(ctx context.Context, _ string, service *
 		klog.Infof("The loadbalancer %s has the following listeners %s", *lb.Status.LoadBalancerID, spew.Sdump(listenerIDs))
 		if len(listenerIDs) <= 0 {
 			klog.Infof("creating listeners for loadbalancers %s, service ports %s", *lb.Status.LoadBalancerID, spew.Sdump(service.Spec.Ports))
-			if err = qc.createListenersAndBackends(conf, lb, service.Spec.Ports, nodes); err != nil {
+			if err = qc.createListenersAndBackends(conf, lb, service.Spec.Ports, nodes, service); err != nil {
 				klog.Errorf("createListenersAndBackends for loadbalancer %s error: %v", *lb.Status.LoadBalancerID, err)
 				return nil, err
 			}
@@ -244,7 +246,7 @@ func (qc *QingCloud) EnsureLoadBalancer(ctx context.Context, _ string, service *
 			}
 
 			//update listerner
-			toDelete, toAdd := diffListeners(listeners, conf, service.Spec.Ports)
+			toDelete, toAdd, toKeep := diffListeners(listeners, conf, service.Spec.Ports)
 			if len(toDelete) > 0 {
 				klog.Infof("listeners %s will be deleted for lb %s", spew.Sdump(toDelete), *lb.Status.LoadBalancerID)
 				err = qc.Client.DeleteListener(toDelete)
@@ -256,38 +258,37 @@ func (qc *QingCloud) EnsureLoadBalancer(ctx context.Context, _ string, service *
 
 			if len(toAdd) > 0 {
 				klog.Infof("listeners  %s will be added for lb %s", spew.Sdump(toAdd), *lb.Status.LoadBalancerID)
-				err = qc.createListenersAndBackends(conf, lb, toAdd, nodes)
+				err = qc.createListenersAndBackends(conf, lb, toAdd, nodes, service)
 				if err != nil {
 					return nil, err
 				}
 				modify = true
 			}
 
 			//update backend; for example, service annotation for backend label changed
-			if len(toAdd) == 0 && len(toDelete) == 0 {
-				for _, listener := range listeners {
-					toDelete, toAdd := diffBackend(listener, nodes)
-
-					if len(toDelete) > 0 {
-						klog.Infof("backends %s will be deleted for listener %s(%s) of lb %s",
-							spew.Sdump(toDelete), *listener.Spec.LoadBalancerListenerName, *listener.Spec.LoadBalancerListenerID, *lb.Status.LoadBalancerID)
-						err = qc.Client.DeleteBackends(toDelete)
-						if err != nil {
-							return nil, err
-						}
-						modify = true
+			for _, listener := range toKeep {
+				// toDelete, toAdd := diffBackend(listener, nodes)
+				toDelete, toAdd := qc.diffBackend(listener, nodes, conf, service)
+
+				if len(toDelete) > 0 {
+					klog.Infof("backends %s will be deleted for listener %s(%s) of lb %s",
+						spew.Sdump(toDelete), *listener.Spec.LoadBalancerListenerName, *listener.Spec.LoadBalancerListenerID, *lb.Status.LoadBalancerID)
+					err = qc.Client.DeleteBackends(toDelete)
+					if err != nil {
+						return nil, err
 					}
+					modify = true
+				}
 
-					toAddBackends := generateLoadBalancerBackends(toAdd, listener, service.Spec.Ports)
-					if len(toAddBackends) > 0 {
-						klog.Infof("backends %s will be added for listener %s(%s) of lb %s",
-							spew.Sdump(toAddBackends), *listener.Spec.LoadBalancerListenerName, *listener.Spec.LoadBalancerListenerID, *lb.Status.LoadBalancerID)
-						_, err = qc.Client.CreateBackends(toAddBackends)
-						if err != nil {
-							return nil, err
-						}
-						modify = true
+				toAddBackends := generateLoadBalancerBackends(toAdd, listener, service.Spec.Ports)
+				if len(toAddBackends) > 0 {
+					klog.Infof("backends %s will be added for listener %s(%s) of lb %s",
+						spew.Sdump(toAddBackends), *listener.Spec.LoadBalancerListenerName, *listener.Spec.LoadBalancerListenerID, *lb.Status.LoadBalancerID)
+					_, err = qc.Client.CreateBackends(toAddBackends)
+					if err != nil {
+						return nil, err
 					}
+					modify = true
 				}
 			}
 
@@ -316,6 +317,7 @@ func (qc *QingCloud) EnsureLoadBalancer(ctx context.Context, _ string, service *
 		//1.2 prepare sg
 		//default sg set by Client auto
 		//1.3 create lb
+		klog.Infof("creating loadbalance for service %s/%s", service.Namespace, service.Name)
 		lb, err = qc.Client.CreateLB(&apis.LoadBalancer{
 			Spec: apis.LoadBalancerSpec{
 				LoadBalancerName: &conf.LoadBalancerName,
@@ -331,7 +333,7 @@ func (qc *QingCloud) EnsureLoadBalancer(ctx context.Context, _ string, service *
 		}
 
 		//create listener
-		if err = qc.createListenersAndBackends(conf, lb, service.Spec.Ports, nodes); err != nil {
+		if err = qc.createListenersAndBackends(conf, lb, service.Spec.Ports, nodes, service); err != nil {
 			return nil, err
 		}
 	} else {
@@ -382,7 +384,8 @@ func (qc *QingCloud) UpdateLoadBalancer(ctx context.Context, _ string, service *
 	}
 
 	for _, listener := range listeners {
-		toDelete, toAdd := diffBackend(listener, nodes)
+		// toDelete, toAdd := diffBackend(listener, nodes)
+		toDelete, toAdd := qc.diffBackend(listener, nodes, conf, service)
 
 		if len(toDelete) > 0 {
 			klog.Infof("backends %s will be deleted for listener %s(%s) of lb %s",
@@ -414,7 +417,7 @@ func (qc *QingCloud) UpdateLoadBalancer(ctx context.Context, _ string, service *
 	return qc.Client.UpdateLB(lb.Status.LoadBalancerID)
 }
 
-func (qc *QingCloud) createListenersAndBackends(conf *LoadBalancerConfig, status *apis.LoadBalancer, ports []v1.ServicePort, nodes []*v1.Node) error {
+func (qc *QingCloud) createListenersAndBackends(conf *LoadBalancerConfig, status *apis.LoadBalancer, ports []v1.ServicePort, nodes []*v1.Node, svc *v1.Service) error {
 	listeners, err := generateLoadBalancerListeners(conf, status, ports)
 	if err != nil {
 		klog.Errorf("generateLoadBalancerListeners for loadbalancer %s error: %v", *status.Status.LoadBalancerID, err)
@@ -426,7 +429,19 @@ func (qc *QingCloud) createListenersAndBackends(conf *LoadBalancerConfig, status
 		return err
 	}
 
-	//create backend
+	// filter backend nodes by count
+	if svc.Spec.ExternalTrafficPolicy == v1.ServiceExternalTrafficPolicyTypeCluster && conf.BackendCountConfig != "" {
+		klog.Infof("service %s/%s has lb backend count annotation, try to get %d random nodes as backend", svc.Namespace, svc.Name, conf.BackendCountResult)
+		nodes = getRandomNodes(nodes, conf.BackendCountResult)
+
+		var resultNames []string
+		for _, node := range nodes {
+			resultNames = append(resultNames, node.Name)
+		}
+		klog.Infof("get random nodes result for service %s/%s: %v", svc.Namespace, svc.Name, resultNames)
+	}
+
+	// create backend
 	for _, listener := range listeners {
 		backends := generateLoadBalancerBackends(nodes, listener, ports)
 		_, err = qc.Client.CreateBackends(backends)
@@ -515,7 +530,7 @@ func (qc *QingCloud) filterNodes(ctx context.Context, svc *v1.Service, nodes []*
 			}
 		}
 	} else {
-		if lbconfog.BackendLabel != "" {
+		if lbconfog.BackendLabel != "" { // filter by node label
 			klog.Infof("filter nodes for service %s/%s by backend label: %s", svc.Namespace, svc.Name, lbconfog.BackendLabel)
 
 			// filter by label
@@ -543,6 +558,28 @@ func (qc *QingCloud) filterNodes(ctx context.Context, svc *v1.Service, nodes []*
 				klog.Infof("there are no available nodes for service %s/%s, use all nodes!", svc.Namespace, svc.Name)
 				newNodes = nodes
 			}
+			// clear lb backend count config
+			lbconfog.BackendCountConfig = ""
+		} else if lbconfog.BackendCountConfig != "" { //filter by backend count config
+			var backendCountResult int
+
+			backendCountConfig, _ := strconv.Atoi(lbconfog.BackendCountConfig)
+			if backendCountConfig > 0 && backendCountConfig <= len(nodes) {
+				backendCountResult = backendCountConfig
+			} else {
+				//invalid count config, use default value (1/3 of all nodes)
+				if len(nodes) <= 3 {
+					backendCountResult = len(nodes)
+				} else {
+					backendCountResult = len(nodes) / 3
+					if backendCountResult < 3 {
+						backendCountResult = DefaultBackendCount
+					}
+				}
+			}
+
+			lbconfog.BackendCountResult = backendCountResult
+			newNodes = nodes
 		} else {
 			// no need to filter
 			newNodes = nodes

pkg/qingcloud/qingcloud_utils.go

@@ -4,9 +4,11 @@ import (
 	"fmt"
 
 	"github.com/davecgh/go-spew/spew"
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/klog/v2"
 
 	"github.com/yunify/qingcloud-cloud-controller-manager/pkg/apis"
+	"github.com/yunify/qingcloud-cloud-controller-manager/pkg/util"
 )
 
 func (qc *QingCloud) prepareEip(eipSource *string) (eip *apis.EIP, err error) {
@@ -143,3 +145,40 @@ func (qc *QingCloud) updateLBEip(config *LoadBalancerConfig, lb *apis.LoadBalanc
 
 	return nil
 }
+
+func (qc *QingCloud) diffBackend(listener *apis.LoadBalancerListener, nodes []*v1.Node, conf *LoadBalancerConfig, svc *v1.Service) (toDelete []*string, toAdd []*v1.Node) {
+	var backendLeftID []*string
+	for _, backend := range listener.Status.LoadBalancerBackends {
+		if !nodesHasBackend(*backend.Spec.LoadBalancerBackendName, nodes) {
+			toDelete = append(toDelete, backend.Status.LoadBalancerBackendID)
+		} else {
+			backendLeftID = append(backendLeftID, backend.Status.LoadBalancerBackendID)
+		}
+	}
+
+	// filter backend nodes by count
+	if svc.Spec.ExternalTrafficPolicy == v1.ServiceExternalTrafficPolicyTypeCluster && conf.BackendCountConfig != "" {
+		backendLeftCount := len(listener.Status.LoadBalancerBackends) - len(toDelete)
+		if backendLeftCount > conf.BackendCountResult {
+			// delete some
+			toDelete = append(toDelete, util.GetRandomItems(backendLeftID, backendLeftCount-conf.BackendCountResult)...)
+		} else {
+			// add some
+			var nodeLeft []*v1.Node
+			for _, node := range nodes {
+				if !backendsHasNode(node, listener.Status.LoadBalancerBackends) {
+					nodeLeft = append(nodeLeft, node)
+				}
+			}
+			toAdd = append(toAdd, getRandomNodes(nodeLeft, conf.BackendCountResult-backendLeftCount)...)
+		}
+	} else {
+		for _, node := range nodes {
+			if !backendsHasNode(node, listener.Status.LoadBalancerBackends) {
+				toAdd = append(toAdd, node)
+			}
+		}
+	}
+
+	return
+}