UPSTREAM: <carry>: support preexisting http.Clients

Co-authored-by: Fabian von Feilitzsch <[email protected]>

Author: ncdc

pkg/client/apiutil/apimachinery.go

@@ -21,6 +21,7 @@ package apiutil
 
 import (
 	"fmt"
+	"net/http"
 	"reflect"
 	"sync"
 
@@ -122,6 +123,13 @@ func RESTClientForGVK(gvk schema.GroupVersionKind, isUnstructured bool, baseConf
 	return rest.RESTClientFor(createRestConfig(gvk, isUnstructured, baseConfig, codecs))
 }
 
+// RESTClientForGVKAndClient constructs a new rest.Interface capable of accessing the resource associated
+// wwith the give GroupVersionKind. The REST client will be configured to use provided http.Client, and the
+// negotiated serializer from baseConfig, if set.
+func RESTClientForGVKAndClient(gvk schema.GroupVersionKind, client *http.Client, isUnstructured bool, baseConfig *rest.Config, codecs serializer.CodecFactory) (rest.Interface, error) {
+	return rest.RESTClientForConfigAndClient(createRestConfig(gvk, isUnstructured, baseConfig, codecs), client)
+}
+
 // serializerWithDecodedGVK is a CodecFactory that overrides the DecoderToVersion of a WithoutConversionCodecFactory
 // in order to avoid clearing the GVK from the decoded object.
 //

pkg/client/client.go

@@ -19,6 +19,7 @@ package client
 import (
 	"context"
 	"fmt"
+	"net/http"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/api/meta"
@@ -57,6 +58,9 @@ type Options struct {
 	// Mapper, if provided, will be used to map GroupVersionKinds to Resources
 	Mapper meta.RESTMapper
 
+	// HTTPClient, if provided, will be used by all constructed clients to talk to the apiserver
+	HTTPClient *http.Client
+
 	// Opts is used to configure the warning handler responsible for
 	// surfacing and handling warnings messages sent by the API server.
 	Opts WarningHandlerOptions
@@ -81,6 +85,14 @@ func newClient(config *rest.Config, options Options) (*client, error) {
 		return nil, fmt.Errorf("must provide non-nil rest.Config to client.New")
 	}
 
+	if options.HTTPClient == nil {
+		httpClient, err := rest.HTTPClientFor(config)
+		if err != nil {
+			return nil, fmt.Errorf("error creating HTTPClient from config: %w", err)
+		}
+		options.HTTPClient = httpClient
+	}
+
 	if !options.Opts.SuppressWarnings {
 		// surface warnings
 		logger := log.Log.WithName("KubeAPIWarningLogger")
@@ -113,16 +125,17 @@ func newClient(config *rest.Config, options Options) (*client, error) {
 	}
 
 	clientcache := &clientCache{
-		config: config,
-		scheme: options.Scheme,
-		mapper: options.Mapper,
-		codecs: serializer.NewCodecFactory(options.Scheme),
+		config:     config,
+		httpClient: options.HTTPClient,
+		scheme:     options.Scheme,
+		mapper:     options.Mapper,
+		codecs:     serializer.NewCodecFactory(options.Scheme),
 
 		structuredResourceByType:   make(map[schema.GroupVersionKind]*resourceMeta),
 		unstructuredResourceByType: make(map[schema.GroupVersionKind]*resourceMeta),
 	}
 
-	rawMetaClient, err := metadata.NewForConfig(config)
+	rawMetaClient, err := metadata.NewForConfigAndClient(config, options.HTTPClient)
 	if err != nil {
 		return nil, fmt.Errorf("unable to construct metadata-only client for use as part of client: %w", err)
 	}

pkg/client/client_cache.go

@@ -17,6 +17,7 @@ limitations under the License.
 package client
 
 import (
+	"net/http"
 	"strings"
 	"sync"
 
@@ -35,6 +36,9 @@ type clientCache struct {
 	// config is the rest.Config to talk to an apiserver
 	config *rest.Config
 
+	// httpClient is the http.Client to talk to an apiserver
+	httpClient *http.Client
+
 	// scheme maps go structs to GroupVersionKinds
 	scheme *runtime.Scheme
 
@@ -59,7 +63,7 @@ func (c *clientCache) newResource(gvk schema.GroupVersionKind, isList, isUnstruc
 		gvk.Kind = gvk.Kind[:len(gvk.Kind)-4]
 	}
 
-	client, err := apiutil.RESTClientForGVK(gvk, isUnstructured, c.config, c.codecs)
+	client, err := apiutil.RESTClientForGVKAndClient(gvk, c.httpClient, isUnstructured, c.config, c.codecs)
 	if err != nil {
 		return nil, err
 	}