[loadbalancingexporter] Support the timeout period of k8s resolver li…

…st watch can be configured (open-telemetry#31904)

**Link to tracking Issue:** close
open-telemetry#31757

---------

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

.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 {