From 5dc909fd9358c3aa7a98ae7bc9d1ab6efe3f65d1 Mon Sep 17 00:00:00 2001
From: Tomy Guichard <tguichard@scaleway.com>
Date: Wed, 22 Jan 2025 15:56:25 +0100
Subject: [PATCH] fix: updateLoadBalancer only when all nodes are initialized

---
 scaleway/loadbalancers.go      | 24 +++++++++++
 scaleway/loadbalancers_test.go | 79 ++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)

diff --git a/scaleway/loadbalancers.go b/scaleway/loadbalancers.go
index 28d5656..fbf2ef0 100644
--- a/scaleway/loadbalancers.go
+++ b/scaleway/loadbalancers.go
@@ -28,6 +28,7 @@ import (
 
 	"golang.org/x/exp/slices"
 	v1 "k8s.io/api/core/v1"
+	"k8s.io/cloud-provider/api"
 	"k8s.io/klog/v2"
 
 	scwipam "github.com/scaleway/scaleway-sdk-go/api/ipam/v1"
@@ -582,6 +583,10 @@ func (l *loadbalancers) updateLoadBalancer(ctx context.Context, loadbalancer *sc
 		return fmt.Errorf("invalid value for annotation %s: expected boolean", serviceAnnotationLoadBalancerExternallyManaged)
 	}
 
+	if err := nodesInitialized(nodes); err != nil {
+		return err
+	}
+
 	nodes = filterNodes(service, nodes)
 	if l.pnID != "" {
 		respPN, err := l.api.ListLBPrivateNetworks(&scwlb.ZonedAPIListLBPrivateNetworksRequest{
@@ -1727,3 +1732,22 @@ func hasEqualLoadBalancerStaticIPs(service *v1.Service, lb *scwlb.LB) bool {
 
 	return true
 }
+
+// nodesInitialized verifies that all nodes are initialized before using them as LoadBalancer targets.
+func nodesInitialized(nodes []*v1.Node) error {
+	for _, node := range nodes {
+		// If node was created more than 3 minutes ago, we ignore it to
+		// avoid blocking callers indefinitely.
+		if time.Since(node.CreationTimestamp.Time) > 3*time.Minute {
+			continue
+		}
+
+		if slices.ContainsFunc(node.Spec.Taints, func(taint v1.Taint) bool {
+			return taint.Key == api.TaintExternalCloudProvider
+		}) {
+			return fmt.Errorf("node %s is not yet initialized", node.Name)
+		}
+	}
+
+	return nil
+}
diff --git a/scaleway/loadbalancers_test.go b/scaleway/loadbalancers_test.go
index 26d5a2e..ee8d2e4 100644
--- a/scaleway/loadbalancers_test.go
+++ b/scaleway/loadbalancers_test.go
@@ -27,6 +27,7 @@ import (
 	"github.com/scaleway/scaleway-sdk-go/scw"
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/cloud-provider/api"
 )
 
 func TestGetValueForPort(t *testing.T) {
@@ -1401,3 +1402,81 @@ func Test_hasEqualLoadBalancerStaticIPs(t *testing.T) {
 		})
 	}
 }
+
+func Test_nodesInitialized(t *testing.T) {
+	type args struct {
+		nodes []*v1.Node
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			name: "node initialized",
+			args: args{
+				nodes: []*v1.Node{
+					{
+						ObjectMeta: metav1.ObjectMeta{
+							Name: "test",
+						},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "node not initialized but created 5 minutes ago",
+			args: args{
+				nodes: []*v1.Node{
+					{
+						ObjectMeta: metav1.ObjectMeta{
+							Name:              "test",
+							CreationTimestamp: metav1.NewTime(time.Now().Add(-5 * time.Minute)),
+						},
+						Spec: v1.NodeSpec{
+							Taints: []v1.Taint{
+								{
+									Key:    api.TaintExternalCloudProvider,
+									Value:  "true",
+									Effect: v1.TaintEffectNoSchedule,
+								},
+							},
+						},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "node not initialized, created 10 seconds ago",
+			args: args{
+				nodes: []*v1.Node{
+					{
+						ObjectMeta: metav1.ObjectMeta{
+							Name:              "test",
+							CreationTimestamp: metav1.NewTime(time.Now().Add(-10 * time.Second)),
+						},
+						Spec: v1.NodeSpec{
+							Taints: []v1.Taint{
+								{
+									Key:    api.TaintExternalCloudProvider,
+									Value:  "true",
+									Effect: v1.TaintEffectNoSchedule,
+								},
+							},
+						},
+					},
+				},
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := nodesInitialized(tt.args.nodes); (err != nil) != tt.wantErr {
+				t.Errorf("nodesInitialized() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}