add default labels

Author: olegy89

serverscom/loadbalancers.go

@@ -19,6 +19,9 @@ const (
 	loadBalancerLocationIdAnnotation    = "servers.com/load-balancer-location-id"
 	loadBalancerProxyProtocolAnnotation = "servers.com/proxy-protocol"
 	loadBalancerClusterAnnotation       = "servers.com/cluster-id"
+
+	loadBalancerServiceUUIDLabel = "k8s.servers.com/service-id"
+	loadBalancerClusterNameLabel = "k8s.servers.com/cluster-name"
 )
 
 type loadBalancers struct {
@@ -71,6 +74,11 @@ func (l *loadBalancers) EnsureLoadBalancer(ctx context.Context, clusterName stri
 	// empty value for cluster id still returns nil
 	lbClusterID := l.extractLBClusterID(service)
 
+	defaultLabels := map[string]string{
+		loadBalancerServiceUUIDLabel: string(service.UID),
+		loadBalancerClusterNameLabel: sanitizeLabelValue(clusterName),
+	}
+
 	if loadBalancer == nil {
 		locationID, err := l.extractLocationID(service)
 		if err != nil {
@@ -83,6 +91,7 @@ func (l *loadBalancers) EnsureLoadBalancer(ctx context.Context, clusterName stri
 		input.LocationID = locationID
 		input.Name = l.GetLoadBalancerName(ctx, clusterName, service)
 		input.ClusterID = lbClusterID
+		input.Labels = defaultLabels
 
 		loadBalancer, err = l.client.LoadBalancers.CreateL4LoadBalancer(ctx, input)
 		if err != nil {
@@ -95,6 +104,7 @@ func (l *loadBalancers) EnsureLoadBalancer(ctx context.Context, clusterName stri
 	} else {
 		name := l.GetLoadBalancerName(ctx, clusterName, service)
 
+		mergedLabels := mergeDefaultLabels(loadBalancer.Labels, defaultLabels)
 		input := cli.L4LoadBalancerUpdateInput{}
 		input.VHostZones = vhostZones
 		input.UpstreamZones = upstreamZones
@@ -104,6 +114,7 @@ func (l *loadBalancers) EnsureLoadBalancer(ctx context.Context, clusterName stri
 			input.SharedCluster = new(bool)
 			*input.SharedCluster = true
 		}
+		input.Labels = mergedLabels
 
 		loadBalancer, err = l.client.LoadBalancers.UpdateL4LoadBalancer(ctx, loadBalancer.ID, input)
 		if err != nil {
@@ -128,13 +139,19 @@ func (l *loadBalancers) UpdateLoadBalancer(ctx context.Context, clusterName stri
 	if err != nil {
 		return err
 	}
+	defaultLabels := map[string]string{
+		loadBalancerServiceUUIDLabel: string(service.UID),
+		loadBalancerClusterNameLabel: sanitizeLabelValue(clusterName),
+	}
+	mergedLabels := mergeDefaultLabels(loadBalancer.Labels, defaultLabels)
 
 	name := l.GetLoadBalancerName(ctx, clusterName, service)
 
 	input := cli.L4LoadBalancerUpdateInput{}
 	input.VHostZones = vhostZones
 	input.UpstreamZones = upstreamZones
 	input.Name = &name
+	input.Labels = mergedLabels
 
 	_, err = l.client.LoadBalancers.UpdateL4LoadBalancer(ctx, loadBalancer.ID, input)
 	if err != nil {

serverscom/utils.go

@@ -2,10 +2,14 @@ package serverscom
 
 import (
 	"fmt"
-	"k8s.io/klog/v2"
 	"regexp"
+	"sort"
 	"strings"
 
+	"k8s.io/klog/v2"
+
+	"maps"
+
 	cli "github.com/serverscom/serverscom-go-client/pkg"
 	v1 "k8s.io/api/core/v1"
 )
@@ -134,3 +138,108 @@ func anyMatch(str string, matches ...*string) bool {
 
 	return false
 }
+
+// sanitizeLabelValue sanitazes label value according to:
+// https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set
+//
+// rules:
+// must be 63 characters or less (can be empty),
+// unless empty, must begin and end with an alphanumeric character ([a-z0-9A-Z]),
+// could contain dashes (-), underscores (_), dots (.), and alphanumerics between.
+//
+// returns empty string if no valid chars found
+func sanitizeLabelValue(value string) string {
+	if len(value) == 0 {
+		return value
+	}
+
+	runes := []rune(value)
+
+	// replace any invalid char to '-'
+	for i, r := range runes {
+		if !isValidLabelChar(r) {
+			runes[i] = '-'
+		}
+	}
+
+	start := 0
+	for start < len(runes) && !isAlphaNumeric(runes[start]) {
+		start++
+	}
+
+	if start == len(runes) {
+		return ""
+	}
+
+	end := len(runes) - 1
+	for end >= 0 && !isAlphaNumeric(runes[end]) {
+		end--
+	}
+
+	runes = runes[start : end+1]
+
+	if len(runes) > 63 {
+		runes = runes[:63]
+
+		// check that after truncate we still have valid chars in the end
+		if !isAlphaNumeric(runes[len(runes)-1]) {
+			lastValid := len(runes) - 1
+			for lastValid >= 0 && !isAlphaNumeric(runes[lastValid]) {
+				lastValid--
+			}
+
+			if lastValid >= 0 {
+				runes = runes[:lastValid+1]
+			} else {
+				return ""
+			}
+		}
+	}
+
+	return string(runes)
+}
+
+func isValidLabelChar(r rune) bool {
+	return isAlphaNumeric(r) || r == '-' || r == '_' || r == '.'
+}
+
+func isAlphaNumeric(r rune) bool {
+	return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9')
+}
+
+// mergeDefaultLabels merge existing labels with default ones.
+// To ensure that we can add default labels, existing labels will sorted by keys and truncated to 64 - count of default labels.
+// 64 - max supported labels for resource.
+func mergeDefaultLabels(existing, defaultLabels map[string]string) map[string]string {
+	if defaultLabels == nil {
+		return existing
+	}
+	if existing == nil {
+		return defaultLabels
+	}
+	// max labels - count of default labels
+	truncateTo := 64 - len(defaultLabels)
+
+	for k := range defaultLabels {
+		delete(existing, k)
+	}
+
+	if len(existing) > truncateTo {
+		keys := make([]string, 0, len(existing))
+		for k := range existing {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+
+		truncated := make(map[string]string, 64)
+		for i := range truncateTo {
+			k := keys[i]
+			truncated[k] = existing[k]
+		}
+		existing = truncated
+	}
+
+	maps.Copy(existing, defaultLabels)
+
+	return existing
+}