From 32a26a455f8515c2dc4620a02b49b4b96c58975b Mon Sep 17 00:00:00 2001
From: Catherine Fang <yinghongfang@google.com>
Date: Wed, 10 Jan 2024 09:36:54 -0500
Subject: [PATCH] Fix OOM issue and "http2: stream closed" issue by returning
 empty ListCustomMetrics

---
 custom-metrics-stackdriver-adapter/Makefile           |  2 +-
 custom-metrics-stackdriver-adapter/adapter.go         |  6 +++++-
 .../pkg/adapter/provider/provider.go                  | 11 +++++++++--
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/custom-metrics-stackdriver-adapter/Makefile b/custom-metrics-stackdriver-adapter/Makefile
index f8318ab66..8a0373d2b 100644
--- a/custom-metrics-stackdriver-adapter/Makefile
+++ b/custom-metrics-stackdriver-adapter/Makefile
@@ -3,7 +3,7 @@ GOOS?=linux
 OUT_DIR?=build
 PACKAGE=github.com/GoogleCloudPlatform/k8s-stackdriver/custom-metrics-stackdriver-adapter
 PREFIX?=staging-k8s.gcr.io
-TAG = v0.13.1
+TAG = v0.14.0
 PKG := $(shell find pkg/* -type f)
 
 .PHONY: build docker push test clean
diff --git a/custom-metrics-stackdriver-adapter/adapter.go b/custom-metrics-stackdriver-adapter/adapter.go
index e72f70db6..e9afd9ac5 100644
--- a/custom-metrics-stackdriver-adapter/adapter.go
+++ b/custom-metrics-stackdriver-adapter/adapter.go
@@ -110,7 +110,7 @@ func (sa *StackdriverAdapter) makeProviderOrDie(o *stackdriverAdapterServerOptio
 	conf.GenericConfig.EnableMetrics = true
 
 	translator := translator.NewTranslator(stackdriverService, gceConf, rateInterval, alignmentPeriod, mapper, o.UseNewResourceModel, o.EnableDistributionSupport)
-	return adapter.NewStackdriverProvider(client, mapper, gceConf, stackdriverService, translator, rateInterval, o.UseNewResourceModel, o.FallbackForContainerMetrics), translator
+	return adapter.NewStackdriverProvider(client, mapper, gceConf, stackdriverService, translator, rateInterval, o.UseNewResourceModel, o.FallbackForContainerMetrics, o.SupportListCustomMetrics), translator
 }
 
 func (sa *StackdriverAdapter) withCoreMetrics(translator *translator.Translator) error {
@@ -154,6 +154,7 @@ func main() {
 		FallbackForContainerMetrics: false,
 		EnableCoreMetricsAPI:        false,
 		EnableDistributionSupport:   false,
+		SupportListCustomMetrics:    false,
 	}
 
 	flags.BoolVar(&serverOptions.UseNewResourceModel, "use-new-resource-model", serverOptions.UseNewResourceModel,
@@ -166,6 +167,8 @@ func main() {
 		"If true, fallbacks to k8s_container resource when given metric is not present on k8s_pod. At most one container with given metric is allowed for each pod.")
 	flags.BoolVar(&serverOptions.EnableCoreMetricsAPI, "enable-core-metrics-api", serverOptions.EnableCoreMetricsAPI,
 		"Experimental, do not use. Whether to enable Core Metrics API.")
+	flags.BoolVar(&serverOptions.SupportListCustomMetrics, "support-list-custom-metrics", serverOptions.SupportListCustomMetrics,
+		"whether to enable External Metrics API")
 	flags.StringVar(&serverOptions.MetricsAddress, "metrics-address", "",
 		"Endpoint with port on which Prometheus metrics server should be enabled. Example: localhost:8080. If there is no flag, Prometheus metric server is disabled and monitoring metrics are not collected.")
 	flags.StringVar(&serverOptions.StackdriverEndpoint, "stackdriver-endpoint", "",
@@ -175,6 +178,7 @@ func main() {
 
 	flags.Parse(os.Args)
 
+	klog.Info("serverOptions: ", serverOptions)
 	if !serverOptions.UseNewResourceModel && serverOptions.FallbackForContainerMetrics {
 		klog.Fatalf("Container metrics work only with new resource model")
 	}
diff --git a/custom-metrics-stackdriver-adapter/pkg/adapter/provider/provider.go b/custom-metrics-stackdriver-adapter/pkg/adapter/provider/provider.go
index c3fcf52e3..f54157f45 100644
--- a/custom-metrics-stackdriver-adapter/pkg/adapter/provider/provider.go
+++ b/custom-metrics-stackdriver-adapter/pkg/adapter/provider/provider.go
@@ -59,10 +59,11 @@ type StackdriverProvider struct {
 	metricsCacheSet             bool
 	metricsCache                []provider.CustomMetricInfo
 	fallbackForContainerMetrics bool
+	supportListCustomMetrics    bool
 }
 
 // NewStackdriverProvider creates a StackdriverProvider
-func NewStackdriverProvider(kubeClient *corev1.CoreV1Client, mapper apimeta.RESTMapper, gceConf *config.GceConfig, stackdriverService *stackdriver.Service, translator *translator.Translator, rateInterval time.Duration, useNewResourceModel bool, fallbackForContainerMetrics bool) provider.MetricsProvider {
+func NewStackdriverProvider(kubeClient *corev1.CoreV1Client, mapper apimeta.RESTMapper, gceConf *config.GceConfig, stackdriverService *stackdriver.Service, translator *translator.Translator, rateInterval time.Duration, useNewResourceModel bool, fallbackForContainerMetrics bool, supportListCustomMetrics bool) provider.MetricsProvider {
 	return &StackdriverProvider{
 		kubeClient:                  kubeClient,
 		stackdriverService:          stackdriverService,
@@ -71,6 +72,7 @@ func NewStackdriverProvider(kubeClient *corev1.CoreV1Client, mapper apimeta.REST
 		translator:                  translator,
 		useNewResourceModel:         useNewResourceModel,
 		fallbackForContainerMetrics: fallbackForContainerMetrics,
+		supportListCustomMetrics:    supportListCustomMetricsm,
 	}
 }
 
@@ -309,8 +311,13 @@ func (p *StackdriverProvider) getNamespacedMetricBySelector(groupResource schema
 }
 
 // ListAllMetrics returns all custom metrics available from Stackdriver.
-// List only pod metrics
 func (p *StackdriverProvider) ListAllMetrics() []provider.CustomMetricInfo {
+	// This can reduce memory usage significantly and ListAllMetrics is not in HPA.
+	if !p.supportListCustomMetric {
+		return []provider.CustomMetricInfo{}
+	}
+
+	// List only pod metrics
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	if !p.metricsCacheSet {