Cache kubernetes API resource discovery (resolves #170) (#176)

VERSION

@@ -1 +1 @@
-0.3.3
+0.4.0

cmd/argocd-application-controller/main.go

@@ -2,8 +2,10 @@ package main
 
 import (
 	"context"
+	"flag"
 	"fmt"
 	"os"
+	"strconv"
 	"time"
 
 	argocd "github.com/argoproj/argo-cd"
@@ -39,6 +41,7 @@ func newCommand() *cobra.Command {
 		repoServerAddress string
 		workers           int
 		logLevel          string
+		glogLevel         int
 	)
 	var command = cobra.Command{
 		Use:   cliName,
@@ -48,6 +51,11 @@ func newCommand() *cobra.Command {
 			errors.CheckError(err)
 			log.SetLevel(level)
 
+			// Set the glog level for the k8s go-client
+			flag.CommandLine.Parse([]string{})
+			flag.Lookup("logtostderr").Value.Set("true")
+			flag.Lookup("v").Value.Set(strconv.Itoa(glogLevel))
+
 			config, err := clientConfig.ClientConfig()
 			errors.CheckError(err)
 
@@ -94,6 +102,7 @@ func newCommand() *cobra.Command {
 	command.Flags().StringVar(&repoServerAddress, "repo-server", "localhost:8081", "Repo server address.")
 	command.Flags().IntVar(&workers, "workers", 1, "Number of application workers")
 	command.Flags().StringVar(&logLevel, "loglevel", "info", "Set the logging level. One of: debug|info|warn|error")
+	command.Flags().IntVar(&glogLevel, "gloglevel", 0, "Set the glog logging level")
 	return &command
 }
 

util/kube/kube.go

@@ -10,7 +10,9 @@ import (
 	"os"
 	"os/exec"
 	"sync"
+	"time"
 
+	"github.com/argoproj/argo-cd/util/cache"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 	"k8s.io/apimachinery/pkg/api/equality"
@@ -41,9 +43,15 @@ const (
 	DeploymentKind = "Deployment"
 )
 
+const (
+	apiResourceCacheDuration = 10 * time.Minute
+)
+
 var (
-	// location to use for generating temporary files, such as the ca.crt needed by kubectl
+	// location to use for generating temporary files, such as the kubeconfig needed by kubectl
 	kubectlTempDir string
+	// apiResourceCache is a in-memory cache of api resources supported by a k8s server
+	apiResourceCache = cache.NewInMemoryCache(apiResourceCacheDuration)
 )
 
 func init() {
@@ -84,19 +92,33 @@ func MustToUnstructured(obj interface{}) *unstructured.Unstructured {
 	return uObj
 }
 
-// ListAPIResources discovers all API resources supported by the Kube API sererver
-func ListAPIResources(disco discovery.DiscoveryInterface) ([]metav1.APIResource, error) {
-	apiResources := make([]metav1.APIResource, 0)
-	resList, err := disco.ServerResources()
+// GetCachedServerResources discovers API resources supported by a Kube API server.
+// Caches the results for apiResourceCacheDuration (per host)
+func GetCachedServerResources(host string, disco discovery.DiscoveryInterface) ([]*metav1.APIResourceList, error) {
+	var resList []*metav1.APIResourceList
+	cacheKey := fmt.Sprintf("apires|%s", host)
+	err := apiResourceCache.Get(cacheKey, &resList)
+	if err == nil {
+		log.Debugf("cache hit: %s", cacheKey)
+		return resList, nil
+	}
+	if err == cache.ErrCacheMiss {
+		log.Infof("cache miss: %s", cacheKey)
+	} else {
+		log.Warnf("cache error %s: %v", cacheKey, err)
+	}
+	resList, err = disco.ServerResources()
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
-	for _, resGroup := range resList {
-		for _, apiRes := range resGroup.APIResources {
-			apiResources = append(apiResources, apiRes)
-		}
+	err = apiResourceCache.Set(&cache.Item{
+		Key:    cacheKey,
+		Object: resList,
+	})
+	if err != nil {
+		log.Warnf("Failed to cache %s: %v", cacheKey, err)
 	}
-	return apiResources, nil
+	return resList, nil
 }
 
 // GetLiveResource returns the corresponding live resource from a unstructured object
@@ -124,7 +146,7 @@ func WatchResourcesWithLabel(ctx context.Context, config *rest.Config, namespace
 	if err != nil {
 		return nil, err
 	}
-	serverResources, err := disco.ServerResources()
+	serverResources, err := GetCachedServerResources(config.Host, disco)
 	if err != nil {
 		return nil, err
 	}
@@ -185,7 +207,7 @@ func GetResourcesWithLabel(config *rest.Config, namespace string, labelName stri
 	if err != nil {
 		return nil, err
 	}
-	resources, err := disco.ServerResources()
+	resources, err := GetCachedServerResources(config.Host, disco)
 	if err != nil {
 		return nil, err
 	}
@@ -251,7 +273,7 @@ func DeleteResourceWithLabel(config *rest.Config, namespace string, labelName st
 	if err != nil {
 		return err
 	}
-	resources, err := disco.ServerResources()
+	resources, err := GetCachedServerResources(config.Host, disco)
 	if err != nil {
 		return err
 	}

util/kube/kube_test.go

@@ -62,14 +62,32 @@ func resourceList() []*metav1.APIResourceList {
 	}
 }
 
-func TestListAPIResources(t *testing.T) {
+func TestGetCachedServerResources(t *testing.T) {
 	kubeclientset := fake.NewSimpleClientset(test.DemoService(), test.DemoDeployment())
 	fakeDiscovery, ok := kubeclientset.Discovery().(*fakediscovery.FakeDiscovery)
 	assert.True(t, ok)
 	fakeDiscovery.Fake.Resources = resourceList()
-	apiRes, err := ListAPIResources(fakeDiscovery)
+	resList, err := GetCachedServerResources("host", fakeDiscovery)
+	count := 0
+	for _, resGroup := range resList {
+		for _ = range resGroup.APIResources {
+			count++
+		}
+	}
 	assert.Nil(t, err)
-	assert.Equal(t, 11, len(apiRes))
+	assert.Equal(t, 11, count)
+
+	// set resources to empty list and make sure we get the cached result
+	fakeDiscovery.Fake.Resources = []*metav1.APIResourceList{}
+	resList, err = GetCachedServerResources("host", fakeDiscovery)
+	count = 0
+	for _, resGroup := range resList {
+		for _ = range resGroup.APIResources {
+			count++
+		}
+	}
+	assert.Nil(t, err)
+	assert.Equal(t, 11, count)
 }
 
 func TestGetLiveResource(t *testing.T) {