Add global caching restmapper

Signed-off-by: Darren Shepherd <darren@acorn.io>

pkg/mapper/mapper.go

@@ -0,0 +1,210 @@
+package mapper
+
+import (
+	"strings"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/restmapper"
+)
+
+var (
+	gvrCache    = map[schema.GroupVersionResource][]schema.GroupVersionKind{}
+	gvrGvrCache = map[schema.GroupVersionResource][]schema.GroupVersionResource{}
+	gkCache     = map[gkKey][]*meta.RESTMapping{}
+	nameCache   = map[string]string{}
+	cacheLock   sync.RWMutex
+)
+
+type gkKey struct {
+	versions string
+	gk       schema.GroupKind
+}
+
+func New(cfg *rest.Config) (meta.RESTMapper, error) {
+	disc, err := discovery.NewDiscoveryClientForConfig(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	return &RESTMapperGlobalCache{
+		disc: disc,
+	}, nil
+}
+
+type RESTMapperGlobalCache struct {
+	disc discovery.DiscoveryInterface
+	api  []*restmapper.APIGroupResources
+}
+
+func (m *RESTMapperGlobalCache) withClient(f func(m meta.RESTMapper) error) error {
+	cacheLock.Lock()
+	defer cacheLock.Unlock()
+
+	shouldRetry := true
+	if len(m.api) == 0 {
+		shouldRetry = false
+		api, err := restmapper.GetAPIGroupResources(m.disc)
+		if err != nil {
+			return err
+		}
+		m.api = api
+	}
+
+	mapper := restmapper.NewDiscoveryRESTMapper(m.api)
+	if err := f(mapper); err == nil {
+		return nil
+	} else {
+		if !shouldRetry {
+			return err
+		}
+	}
+
+	api, err := restmapper.GetAPIGroupResources(m.disc)
+	if err != nil {
+		return err
+	}
+	m.api = api
+
+	return f(restmapper.NewDiscoveryRESTMapper(m.api))
+}
+
+func (m *RESTMapperGlobalCache) KindFor(resource schema.GroupVersionResource) (schema.GroupVersionKind, error) {
+	gvk, err := m.KindsFor(resource)
+	if err != nil {
+		return schema.GroupVersionKind{}, nil
+	}
+	return gvk[0], nil
+}
+
+func (m *RESTMapperGlobalCache) KindsFor(resource schema.GroupVersionResource) ([]schema.GroupVersionKind, error) {
+	cacheLock.RLock()
+	gvks, ok := gvrCache[resource]
+	cacheLock.RUnlock()
+
+	if ok {
+		return gvks, nil
+	}
+
+	logrus.Debugf("RESTMapperGlobalCache cache miss for %v", resource)
+
+	var err error
+	err = m.withClient(func(m meta.RESTMapper) error {
+		gvks, err = m.KindsFor(resource)
+		return err
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	cacheLock.Lock()
+	gvrCache[resource] = gvks
+	cacheLock.Unlock()
+
+	return gvks, nil
+}
+
+func (m *RESTMapperGlobalCache) ResourceFor(input schema.GroupVersionResource) (schema.GroupVersionResource, error) {
+	gvrs, err := m.ResourcesFor(input)
+	if err != nil {
+		return schema.GroupVersionResource{}, err
+	}
+	return gvrs[0], nil
+}
+
+func (m *RESTMapperGlobalCache) ResourcesFor(input schema.GroupVersionResource) ([]schema.GroupVersionResource, error) {
+	cacheLock.RLock()
+	gvrs, ok := gvrGvrCache[input]
+	cacheLock.RUnlock()
+
+	if ok {
+		return gvrs, nil
+	}
+
+	logrus.Debugf("RESTMapperGlobalCache cache miss for %v", input)
+
+	var err error
+	err = m.withClient(func(m meta.RESTMapper) error {
+		gvrs, err = m.ResourcesFor(input)
+		return err
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	cacheLock.Lock()
+	gvrGvrCache[input] = gvrs
+	cacheLock.Unlock()
+
+	return gvrs, nil
+}
+
+func (m *RESTMapperGlobalCache) RESTMapping(gk schema.GroupKind, versions ...string) (*meta.RESTMapping, error) {
+	mappings, err := m.RESTMappings(gk, versions...)
+	if err != nil {
+		return nil, err
+	}
+	return mappings[0], nil
+}
+
+func (m *RESTMapperGlobalCache) RESTMappings(gk schema.GroupKind, versions ...string) ([]*meta.RESTMapping, error) {
+	key := gkKey{
+		versions: strings.Join(versions, "|"),
+		gk:       gk,
+	}
+	cacheLock.RLock()
+	mappings, ok := gkCache[key]
+	cacheLock.RUnlock()
+
+	if ok {
+		return mappings, nil
+	}
+
+	logrus.Debugf("RESTMapperGlobalCache cache miss for %v, %v", gk, versions)
+
+	var err error
+	err = m.withClient(func(m meta.RESTMapper) error {
+		mappings, err = m.RESTMappings(gk)
+		return err
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	cacheLock.Lock()
+	gkCache[key] = mappings
+	cacheLock.Unlock()
+
+	return mappings, nil
+}
+
+func (m *RESTMapperGlobalCache) ResourceSingularizer(resource string) (string, error) {
+	cacheLock.RLock()
+	singular, ok := nameCache[resource]
+	cacheLock.RUnlock()
+
+	if ok {
+		return singular, nil
+	}
+
+	logrus.Debugf("RESTMapperGlobalCache cache miss for %s", resource)
+
+	var err error
+	err = m.withClient(func(m meta.RESTMapper) error {
+		singular, err = m.ResourceSingularizer(resource)
+		return err
+	})
+	if err != nil {
+		return "", err
+	}
+
+	cacheLock.Lock()
+	nameCache[resource] = singular
+	cacheLock.Unlock()
+
+	return singular, nil
+}

pkg/runtime/clients.go

@@ -3,6 +3,7 @@ package runtime
 import (
 	"time"
 
+	"github.com/acorn-io/baaah/pkg/mapper"
 	"github.com/acorn-io/baaah/pkg/runtime/multi"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/rest"
@@ -71,8 +72,14 @@ func NewRuntimeWithConfigs(defaultConfig Config, apiGroupConfigs map[string]Conf
 }
 
 func getClients(cfg Config, scheme *runtime.Scheme) (uncachedClient client.WithWatch, cachedClient client.Client, theCache cache.Cache, err error) {
+	mapper, err := mapper.New(cfg.Rest)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
 	uncachedClient, err = client.NewWithWatch(cfg.Rest, client.Options{
 		Scheme: scheme,
+		Mapper: mapper,
 	})
 	if err != nil {
 		return nil, nil, nil, err
@@ -84,6 +91,7 @@ func getClients(cfg Config, scheme *runtime.Scheme) (uncachedClient client.WithW
 	}
 
 	theCache, err = cache.New(cfg.Rest, cache.Options{
+		Mapper:     mapper,
 		Scheme:     scheme,
 		Namespaces: namespaces,
 	})
@@ -93,6 +101,7 @@ func getClients(cfg Config, scheme *runtime.Scheme) (uncachedClient client.WithW
 
 	cachedClient, err = client.New(cfg.Rest, client.Options{
 		Scheme: scheme,
+		Mapper: mapper,
 		Cache: &client.CacheOptions{
 			Reader: theCache,
 		},