[loadbalancingexporter] Support the timeout period of k8s resolver list watch can be configured (#31904)

**Link to tracking Issue:** close
#31757

---------

Signed-off-by: Jared Tan <[email protected]>

Author: JaredTan95

.chloggen/support_timeout_configurable_for_k8s_resolver.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: loadbalancingexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Support the timeout period of k8s resolver list watch can be configured.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [31757]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

exporter/loadbalancingexporter/README.md

@@ -70,6 +70,7 @@ Refer to [config.yaml](./testdata/config.yaml) for detailed examples on using th
 * The `k8s` node accepts the following optional properties:
   * `service` Kubernetes service to resolve, e.g. `lb-svc.lb-ns`. If no namespace is specified, an attempt will be made to infer the namespace for this collector, and if this fails it will fall back to the `default` namespace.
   * `ports` port to be used for exporting the traces to the addresses resolved from `service`. If `ports` is not specified, the default port 4317 is used. When multiple ports are specified, two backends are added to the load balancer as if they were at different pods.
+  * `timeout` resolver timeout in go-Duration format, e.g. `5s`, `1d`, `30m`. If not specified, `1s` will be used.
 * The `awsCloudMap` node accepts the following properties:
   * `namespace` The CloudMap namespace where the service is register, e.g. `cloudmap`. If no `namespace` is specified, this will fail to start the Load Balancer exporter.
   * `serviceName` The name of the service that you specified when you registered the instance, e.g. `otelcollectors`.  If no `serviceName` is specified, this will fail to start the Load Balancer exporter.

exporter/loadbalancingexporter/config.go

@@ -54,8 +54,9 @@ type DNSResolver struct {
 
 // K8sSvcResolver defines the configuration for the DNS resolver
 type K8sSvcResolver struct {
-	Service string  `mapstructure:"service"`
-	Ports   []int32 `mapstructure:"ports"`
+	Service string        `mapstructure:"service"`
+	Ports   []int32       `mapstructure:"ports"`
+	Timeout time.Duration `mapstructure:"timeout"`
 }
 
 type AWSCloudMapResolver struct {

exporter/loadbalancingexporter/loadbalancer.go

@@ -85,7 +85,7 @@ func newLoadBalancer(params exporter.CreateSettings, cfg component.Config, facto
 		if err != nil {
 			return nil, err
 		}
-		res, err = newK8sResolver(clt, k8sLogger, oCfg.Resolver.K8sSvc.Service, oCfg.Resolver.K8sSvc.Ports)
+		res, err = newK8sResolver(clt, k8sLogger, oCfg.Resolver.K8sSvc.Service, oCfg.Resolver.K8sSvc.Ports, oCfg.Resolver.K8sSvc.Timeout)
 		if err != nil {
 			return nil, err
 		}

exporter/loadbalancingexporter/resolver_k8s.go

@@ -13,6 +13,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 
 	"go.opencensus.io/stats"
 	"go.opencensus.io/tag"
@@ -37,6 +38,10 @@ var (
 	k8sResolverSuccessFalseMutators = []tag.Mutator{k8sResolverMutator, successFalseMutator}
 )
 
+const (
+	defaultListWatchTimeout = 1 * time.Second
+)
+
 type k8sResolver struct {
 	logger  *zap.Logger
 	svcName string
@@ -48,6 +53,8 @@ type k8sResolver struct {
 	epsListWatcher cache.ListerWatcher
 	endpointsStore *sync.Map
 
+	lwTimeout time.Duration
+
 	endpoints         []string
 	onChangeCallbacks []func([]string)
 
@@ -60,12 +67,16 @@ type k8sResolver struct {
 func newK8sResolver(clt kubernetes.Interface,
 	logger *zap.Logger,
 	service string,
-	ports []int32) (*k8sResolver, error) {
+	ports []int32, timeout time.Duration) (*k8sResolver, error) {
 
 	if len(service) == 0 {
 		return nil, errNoSvc
 	}
 
+	if timeout == 0 {
+		timeout = defaultListWatchTimeout
+	}
+
 	nAddr := strings.SplitN(service, ".", 2)
 	name, namespace := nAddr[0], "default"
 	if len(nAddr) > 1 {
@@ -84,12 +95,12 @@ func newK8sResolver(clt kubernetes.Interface,
 	epsListWatcher := &cache.ListWatch{
 		ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
 			options.FieldSelector = epsSelector
-			options.TimeoutSeconds = ptr.To[int64](1)
+			options.TimeoutSeconds = ptr.To[int64](int64(timeout.Seconds()))
 			return clt.CoreV1().Endpoints(namespace).List(context.Background(), options)
 		},
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			options.FieldSelector = epsSelector
-			options.TimeoutSeconds = ptr.To[int64](1)
+			options.TimeoutSeconds = ptr.To[int64](int64(timeout.Seconds()))
 			return clt.CoreV1().Endpoints(namespace).Watch(context.Background(), options)
 		},
 	}
@@ -106,6 +117,7 @@ func newK8sResolver(clt kubernetes.Interface,
 		epsListWatcher: epsListWatcher,
 		handler:        h,
 		stopCh:         make(chan struct{}),
+		lwTimeout:      timeout,
 	}
 	h.callback = r.resolve
 
@@ -134,7 +146,8 @@ func (r *k8sResolver) start(_ context.Context) error {
 	r.logger.Debug("K8s service resolver started",
 		zap.String("service", r.svcName),
 		zap.String("namespace", r.svcNs),
-		zap.Int32s("ports", r.port))
+		zap.Int32s("ports", r.port),
+		zap.Duration("timeout", r.lwTimeout))
 	return nil
 }
 

exporter/loadbalancingexporter/resolver_k8s_test.go

@@ -56,7 +56,7 @@ func TestK8sResolve(t *testing.T) {
 		}
 
 		cl := fake.NewSimpleClientset(endpoint)
-		res, err := newK8sResolver(cl, zap.NewNop(), service, ports)
+		res, err := newK8sResolver(cl, zap.NewNop(), service, ports, defaultListWatchTimeout)
 		require.NoError(t, err)
 
 		require.NoError(t, res.start(context.Background()))
@@ -241,7 +241,7 @@ func Test_newK8sResolver(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := newK8sResolver(fake.NewSimpleClientset(), tt.args.logger, tt.args.service, tt.args.ports)
+			got, err := newK8sResolver(fake.NewSimpleClientset(), tt.args.logger, tt.args.service, tt.args.ports, defaultListWatchTimeout)
 			if tt.wantErr != nil {
 				require.Error(t, err, tt.wantErr)
 			} else {