1 files changed, 285 insertions, 0 deletions
diff --git a/vendor/sigs.k8s.io/controller-runtime/pkg/client/apiutil/dynamicrestmapper.go b/vendor/sigs.k8s.io/controller-runtime/pkg/client/apiutil/dynamicrestmapper.go
new file mode 100644
index 000000000..56a00371f
--- /dev/null
+++ b/vendor/sigs.k8s.io/controller-runtime/pkg/client/apiutil/dynamicrestmapper.go
@@ -0,0 +1,285 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apiutil
+
+import (
+	"errors"
+	"sync"
+
+	"golang.org/x/time/rate"
+	"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"
+)
+
+// dynamicRESTMapper is a RESTMapper that dynamically discovers resource
+// types at runtime.
+type dynamicRESTMapper struct {
+	mu           sync.RWMutex // protects the following fields
+	staticMapper meta.RESTMapper
+	limiter      *rate.Limiter
+	newMapper    func() (meta.RESTMapper, error)
+
+	lazy bool
+	// Used for lazy init.
+	initOnce sync.Once
+}
+
+// DynamicRESTMapperOption is a functional option on the dynamicRESTMapper.
+type DynamicRESTMapperOption func(*dynamicRESTMapper) error
+
+// WithLimiter sets the RESTMapper's underlying limiter to lim.
+func WithLimiter(lim *rate.Limiter) DynamicRESTMapperOption {
+	return func(drm *dynamicRESTMapper) error {
+		drm.limiter = lim
+		return nil
+	}
+}
+
+// WithLazyDiscovery prevents the RESTMapper from discovering REST mappings
+// until an API call is made.
+var WithLazyDiscovery DynamicRESTMapperOption = func(drm *dynamicRESTMapper) error {
+	drm.lazy = true
+	return nil
+}
+
+// WithCustomMapper supports setting a custom RESTMapper refresher instead of
+// the default method, which uses a discovery client.
+//
+// This exists mainly for testing, but can be useful if you need tighter control
+// over how discovery is performed, which discovery endpoints are queried, etc.
+func WithCustomMapper(newMapper func() (meta.RESTMapper, error)) DynamicRESTMapperOption {
+	return func(drm *dynamicRESTMapper) error {
+		drm.newMapper = newMapper
+		return nil
+	}
+}
+
+// NewDynamicRESTMapper returns a dynamic RESTMapper for cfg. The dynamic
+// RESTMapper dynamically discovers resource types at runtime. opts
+// configure the RESTMapper.
+func NewDynamicRESTMapper(cfg *rest.Config, opts ...DynamicRESTMapperOption) (meta.RESTMapper, error) {
+	client, err := discovery.NewDiscoveryClientForConfig(cfg)
+	if err != nil {
+		return nil, err
+	}
+	drm := &dynamicRESTMapper{
+		limiter: rate.NewLimiter(rate.Limit(defaultRefillRate), defaultLimitSize),
+		newMapper: func() (meta.RESTMapper, error) {
+			groupResources, err := restmapper.GetAPIGroupResources(client)
+			if err != nil {
+				return nil, err
+			}
+			return restmapper.NewDiscoveryRESTMapper(groupResources), nil
+		},
+	}
+	for _, opt := range opts {
+		if err = opt(drm); err != nil {
+			return nil, err
+		}
+	}
+	if !drm.lazy {
+		if err := drm.setStaticMapper(); err != nil {
+			return nil, err
+		}
+	}
+	return drm, nil
+}
+
+var (
+	// defaultRefilRate is the default rate at which potential calls are
+	// added back to the "bucket" of allowed calls.
+	defaultRefillRate = 5
+	// defaultLimitSize is the default starting/max number of potential calls
+	// per second.  Once a call is used, it's added back to the bucket at a rate
+	// of defaultRefillRate per second.
+	defaultLimitSize = 5
+)
+
+// setStaticMapper sets drm's staticMapper by querying its client, regardless
+// of reload backoff.
+func (drm *dynamicRESTMapper) setStaticMapper() error {
+	newMapper, err := drm.newMapper()
+	if err != nil {
+		return err
+	}
+	drm.staticMapper = newMapper
+	return nil
+}
+
+// init initializes drm only once if drm is lazy.
+func (drm *dynamicRESTMapper) init() (err error) {
+	drm.initOnce.Do(func() {
+		if drm.lazy {
+			err = drm.setStaticMapper()
+		}
+	})
+	return err
+}
+
+// checkAndReload attempts to call the given callback, which is assumed to be dependent
+// on the data in the restmapper.
+//
+// If the callback returns an error that matches the given error, it will attempt to reload
+// the RESTMapper's data and re-call the callback once that's occurred.
+// If the callback returns any other error, the function will return immediately regardless.
+//
+// It will take care of ensuring that reloads are rate-limited and that extraneous calls
+// aren't made. If a reload would exceed the limiters rate, it returns the error return by
+// the callback.
+// It's thread-safe, and worries about thread-safety for the callback (so the callback does
+// not need to attempt to lock the restmapper).
+func (drm *dynamicRESTMapper) checkAndReload(needsReloadErr error, checkNeedsReload func() error) error {
+	// first, check the common path -- data is fresh enough
+	// (use an IIFE for the lock's defer)
+	err := func() error {
+		drm.mu.RLock()
+		defer drm.mu.RUnlock()
+
+		return checkNeedsReload()
+	}()
+
+	// NB(directxman12): `Is` and `As` have a confusing relationship --
+	// `Is` is like `== or does this implement .Is`, whereas `As` says
+	// `can I type-assert into`
+	needsReload := errors.As(err, &needsReloadErr)
+	if !needsReload {
+		return err
+	}
+
+	// if the data wasn't fresh, we'll need to try and update it, so grab the lock...
+	drm.mu.Lock()
+	defer drm.mu.Unlock()
+
+	// ... and double-check that we didn't reload in the meantime
+	err = checkNeedsReload()
+	needsReload = errors.As(err, &needsReloadErr)
+	if !needsReload {
+		return err
+	}
+
+	// we're still stale, so grab a rate-limit token if we can...
+	if !drm.limiter.Allow() {
+		// return error from static mapper here, we have refreshed often enough (exceeding rate of provided limiter)
+		// so that client's can handle this the same way as a "normal" NoResourceMatchError / NoKindMatchError
+		return err
+	}
+
+	// ...reload...
+	if err := drm.setStaticMapper(); err != nil {
+		return err
+	}
+
+	// ...and return the results of the closure regardless
+	return checkNeedsReload()
+}
+
+// TODO: wrap reload errors on NoKindMatchError with go 1.13 errors.
+
+func (drm *dynamicRESTMapper) KindFor(resource schema.GroupVersionResource) (schema.GroupVersionKind, error) {
+	if err := drm.init(); err != nil {
+		return schema.GroupVersionKind{}, err
+	}
+	var gvk schema.GroupVersionKind
+	err := drm.checkAndReload(&meta.NoResourceMatchError{}, func() error {
+		var err error
+		gvk, err = drm.staticMapper.KindFor(resource)
+		return err
+	})
+	return gvk, err
+}
+
+func (drm *dynamicRESTMapper) KindsFor(resource schema.GroupVersionResource) ([]schema.GroupVersionKind, error) {
+	if err := drm.init(); err != nil {
+		return nil, err
+	}
+	var gvks []schema.GroupVersionKind
+	err := drm.checkAndReload(&meta.NoResourceMatchError{}, func() error {
+		var err error
+		gvks, err = drm.staticMapper.KindsFor(resource)
+		return err
+	})
+	return gvks, err
+}
+
+func (drm *dynamicRESTMapper) ResourceFor(input schema.GroupVersionResource) (schema.GroupVersionResource, error) {
+	if err := drm.init(); err != nil {
+		return schema.GroupVersionResource{}, err
+	}
+
+	var gvr schema.GroupVersionResource
+	err := drm.checkAndReload(&meta.NoResourceMatchError{}, func() error {
+		var err error
+		gvr, err = drm.staticMapper.ResourceFor(input)
+		return err
+	})
+	return gvr, err
+}
+
+func (drm *dynamicRESTMapper) ResourcesFor(input schema.GroupVersionResource) ([]schema.GroupVersionResource, error) {
+	if err := drm.init(); err != nil {
+		return nil, err
+	}
+	var gvrs []schema.GroupVersionResource
+	err := drm.checkAndReload(&meta.NoResourceMatchError{}, func() error {
+		var err error
+		gvrs, err = drm.staticMapper.ResourcesFor(input)
+		return err
+	})
+	return gvrs, err
+}
+
+func (drm *dynamicRESTMapper) RESTMapping(gk schema.GroupKind, versions ...string) (*meta.RESTMapping, error) {
+	if err := drm.init(); err != nil {
+		return nil, err
+	}
+	var mapping *meta.RESTMapping
+	err := drm.checkAndReload(&meta.NoKindMatchError{}, func() error {
+		var err error
+		mapping, err = drm.staticMapper.RESTMapping(gk, versions...)
+		return err
+	})
+	return mapping, err
+}
+
+func (drm *dynamicRESTMapper) RESTMappings(gk schema.GroupKind, versions ...string) ([]*meta.RESTMapping, error) {
+	if err := drm.init(); err != nil {
+		return nil, err
+	}
+	var mappings []*meta.RESTMapping
+	err := drm.checkAndReload(&meta.NoKindMatchError{}, func() error {
+		var err error
+		mappings, err = drm.staticMapper.RESTMappings(gk, versions...)
+		return err
+	})
+	return mappings, err
+}
+
+func (drm *dynamicRESTMapper) ResourceSingularizer(resource string) (string, error) {
+	if err := drm.init(); err != nil {
+		return "", err
+	}
+	var singular string
+	err := drm.checkAndReload(&meta.NoResourceMatchError{}, func() error {
+		var err error
+		singular, err = drm.staticMapper.ResourceSingularizer(resource)
+		return err
+	})
+	return singular, err
+}