Add cache on provider scope

Author: alexandrevilain

main.go

@@ -71,6 +71,7 @@ var (
 	lbProvider                  string
 	caCertsPath                 string
 	showVersion                 bool
+	scopeCacheMaxSize           int
 	logOptions                  = logs.NewOptions()
 )
 
@@ -137,6 +138,8 @@ func InitFlags(fs *pflag.FlagSet) {
 
 	fs.StringVar(&caCertsPath, "ca-certs", "", "The path to a PEM-encoded CA Certificate file to supply as default for each request.")
 
+	fs.IntVar(&scopeCacheMaxSize, "scope-cache-max-size", 10, "The maximum credentials count the operator should keep in cache. Setting this value to 0 means no cache.")
+
 	fs.BoolVar(&showVersion, "version", false, "Show current version and exit.")
 }
 
@@ -209,8 +212,10 @@ func main() {
 	// Initialize event recorder.
 	record.InitFromRecorder(mgr.GetEventRecorderFor("openstack-controller"))
 
+	scopeFactory := scope.NewScopeFactory(scopeCacheMaxSize)
+
 	setupChecks(mgr)
-	setupReconcilers(ctx, mgr, caCerts)
+	setupReconcilers(ctx, mgr, caCerts, scopeFactory)
 	setupWebhooks(mgr)
 
 	// +kubebuilder:scaffold:builder
@@ -233,12 +238,12 @@ func setupChecks(mgr ctrl.Manager) {
 	}
 }
 
-func setupReconcilers(ctx context.Context, mgr ctrl.Manager, caCerts []byte) {
+func setupReconcilers(ctx context.Context, mgr ctrl.Manager, caCerts []byte, scopeFactory scope.Factory) {
 	if err := (&controllers.OpenStackClusterReconciler{
 		Client:           mgr.GetClient(),
 		Recorder:         mgr.GetEventRecorderFor("openstackcluster-controller"),
 		WatchFilterValue: watchFilterValue,
-		ScopeFactory:     scope.ScopeFactory,
+		ScopeFactory:     scopeFactory,
 		CaCertificates:   caCerts,
 	}).SetupWithManager(ctx, mgr, concurrency(openStackClusterConcurrency)); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", "OpenStackCluster")
@@ -248,7 +253,7 @@ func setupReconcilers(ctx context.Context, mgr ctrl.Manager, caCerts []byte) {
 		Client:           mgr.GetClient(),
 		Recorder:         mgr.GetEventRecorderFor("openstackmachine-controller"),
 		WatchFilterValue: watchFilterValue,
-		ScopeFactory:     scope.ScopeFactory,
+		ScopeFactory:     scopeFactory,
 		CaCertificates:   caCerts,
 	}).SetupWithManager(ctx, mgr, concurrency(openStackMachineConcurrency)); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", "OpenStackMachine")

pkg/scope/mock.go

@@ -18,9 +18,11 @@ package scope
 
 import (
 	"context"
+	"time"
 
 	"github.com/go-logr/logr"
 	"github.com/golang/mock/gomock"
+	"github.com/gophercloud/gophercloud/openstack/identity/v3/tokens"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	infrav1 "sigs.k8s.io/cluster-api-provider-openstack/api/v1alpha7"
@@ -105,3 +107,7 @@ func (f *MockScopeFactory) Logger() logr.Logger {
 func (f *MockScopeFactory) ProjectID() string {
 	return f.projectID
 }
+
+func (f *MockScopeFactory) ExtractToken() (*tokens.Token, error) {
+	return &tokens.Token{ExpiresAt: time.Now().Add(24 * time.Hour)}, nil
+}

pkg/scope/provider.go

@@ -22,6 +22,7 @@ import (
 	"crypto/x509"
 	"fmt"
 	"net/http"
+	"time"
 
 	"github.com/go-logr/logr"
 	"github.com/gophercloud/gophercloud"
@@ -31,12 +32,14 @@ import (
 	"github.com/gophercloud/utils/openstack/clientconfig"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/cache"
 	"k8s.io/klog/v2"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/yaml"
 
 	infrav1 "sigs.k8s.io/cluster-api-provider-openstack/api/v1alpha7"
 	"sigs.k8s.io/cluster-api-provider-openstack/pkg/clients"
+	"sigs.k8s.io/cluster-api-provider-openstack/pkg/utils/hash"
 	"sigs.k8s.io/cluster-api-provider-openstack/version"
 )
 
@@ -45,9 +48,11 @@ const (
 	caSecretKey     = "cacert"
 )
 
-type providerScopeFactory struct{}
+type providerScopeFactory struct {
+	cache *cache.LRUExpireCache
+}
 
-func (providerScopeFactory) NewClientScopeFromMachine(ctx context.Context, ctrlClient client.Client, openStackMachine *infrav1.OpenStackMachine, defaultCACert []byte, logger logr.Logger) (Scope, error) {
+func (f *providerScopeFactory) NewClientScopeFromMachine(ctx context.Context, ctrlClient client.Client, openStackMachine *infrav1.OpenStackMachine, defaultCACert []byte, logger logr.Logger) (Scope, error) {
 	var cloud clientconfig.Cloud
 	var caCert []byte
 
@@ -63,10 +68,14 @@ func (providerScopeFactory) NewClientScopeFromMachine(ctx context.Context, ctrlC
 		caCert = defaultCACert
 	}
 
-	return NewProviderScope(cloud, caCert, logger)
+	if f.cache == nil {
+		return NewProviderScope(cloud, caCert, logger)
+	}
+
+	return NewCachedProviderScope(f.cache, cloud, caCert, logger)
 }
 
-func (providerScopeFactory) NewClientScopeFromCluster(ctx context.Context, ctrlClient client.Client, openStackCluster *infrav1.OpenStackCluster, defaultCACert []byte, logger logr.Logger) (Scope, error) {
+func (f *providerScopeFactory) NewClientScopeFromCluster(ctx context.Context, ctrlClient client.Client, openStackCluster *infrav1.OpenStackCluster, defaultCACert []byte, logger logr.Logger) (Scope, error) {
 	var cloud clientconfig.Cloud
 	var caCert []byte
 
@@ -82,7 +91,20 @@ func (providerScopeFactory) NewClientScopeFromCluster(ctx context.Context, ctrlC
 		caCert = defaultCACert
 	}
 
-	return NewProviderScope(cloud, caCert, logger)
+	if f.cache == nil {
+		return NewProviderScope(cloud, caCert, logger)
+	}
+
+	return NewCachedProviderScope(f.cache, cloud, caCert, logger)
+}
+
+func getScopeCacheKey(cloud clientconfig.Cloud) (string, error) {
+	key, err := hash.ComputeSpewHash(cloud)
+	if err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%d", key), nil
 }
 
 type providerScope struct {
@@ -106,6 +128,34 @@ func NewProviderScope(cloud clientconfig.Cloud, caCert []byte, logger logr.Logge
 	}, nil
 }
 
+func NewCachedProviderScope(cache *cache.LRUExpireCache, cloud clientconfig.Cloud, caCert []byte, logger logr.Logger) (Scope, error) {
+	key, err := getScopeCacheKey(cloud)
+	if err != nil {
+		return nil, fmt.Errorf("can't compute cloud config cache key: %w", err)
+	}
+
+	if scope, found := cache.Get(key); found {
+		logger.V(6).Info("Using scope from cache")
+		return scope.(Scope), nil
+	}
+
+	scope, err := NewProviderScope(cloud, caCert, logger)
+	if err != nil {
+		return nil, err
+	}
+
+	token, err := scope.ExtractToken()
+	if err != nil {
+		return nil, err
+	}
+
+	// compute the token expiration time
+	expiry := time.Until(token.ExpiresAt) / 2
+
+	cache.Add(key, scope, expiry)
+	return scope, nil
+}
+
 func (s *providerScope) Logger() logr.Logger {
 	return s.logger
 }
@@ -134,6 +184,14 @@ func (s *providerScope) NewLbClient() (clients.LbClient, error) {
 	return clients.NewLbClient(s.providerClient, s.providerClientOpts)
 }
 
+func (s *providerScope) ExtractToken() (*tokens.Token, error) {
+	client, err := openstack.NewIdentityV3(s.providerClient, gophercloud.EndpointOpts{})
+	if err != nil {
+		return nil, fmt.Errorf("can't create a new identity service client: %w", err)
+	}
+	return tokens.Get(client, s.providerClient.Token()).ExtractToken()
+}
+
 func NewProviderClient(cloud clientconfig.Cloud, caCert []byte, logger logr.Logger) (*gophercloud.ProviderClient, *clientconfig.ClientOpts, string, error) {
 	clientOpts := new(clientconfig.ClientOpts)
 	if cloud.AuthInfo != nil {

pkg/scope/scope.go

@@ -20,14 +20,24 @@ import (
 	"context"
 
 	"github.com/go-logr/logr"
+	"github.com/gophercloud/gophercloud/openstack/identity/v3/tokens"
+	"k8s.io/apimachinery/pkg/util/cache"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	infrav1 "sigs.k8s.io/cluster-api-provider-openstack/api/v1alpha7"
 	"sigs.k8s.io/cluster-api-provider-openstack/pkg/clients"
 )
 
-// ScopeFactory is the default scope factory. It generates service clients which make OpenStack API calls against a running cloud.
-var ScopeFactory Factory = providerScopeFactory{}
+// NewScopeFactory creates the default scope factory. It generates service clients which make OpenStack API calls against a running cloud.
+func NewScopeFactory(maxCacheSize int) Factory {
+	var c *cache.LRUExpireCache
+	if maxCacheSize > 0 {
+		c = cache.NewLRUExpireCache(maxCacheSize)
+	}
+	return &providerScopeFactory{
+		cache: c,
+	}
+}
 
 // Factory instantiates a new Scope using credentials from either a cluster or a machine.
 type Factory interface {
@@ -44,4 +54,5 @@ type Scope interface {
 	NewLbClient() (clients.LbClient, error)
 	Logger() logr.Logger
 	ProjectID() string
+	ExtractToken() (*tokens.Token, error)
 }