WTF-539 Add missing vendored dependencies back

vendor/k8s.io/client-go/transport/cache.go

@@ -0,0 +1,117 @@
+/*
+Copyright 2015 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 transport
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"sync"
+	"time"
+
+	utilnet "k8s.io/apimachinery/pkg/util/net"
+)
+
+// TlsTransportCache caches TLS http.RoundTrippers different configurations. The
+// same RoundTripper will be returned for configs with identical TLS options If
+// the config has no custom TLS options, http.DefaultTransport is returned.
+type tlsTransportCache struct {
+	mu         sync.Mutex
+	transports map[tlsCacheKey]*http.Transport
+}
+
+const idleConnsPerHost = 25
+
+var tlsCache = &tlsTransportCache{transports: make(map[tlsCacheKey]*http.Transport)}
+
+type tlsCacheKey struct {
+	insecure   bool
+	caData     string
+	certData   string
+	keyData    string
+	getCert    string
+	serverName string
+	dial       string
+}
+
+func (t tlsCacheKey) String() string {
+	keyText := "<none>"
+	if len(t.keyData) > 0 {
+		keyText = "<redacted>"
+	}
+	return fmt.Sprintf("insecure:%v, caData:%#v, certData:%#v, keyData:%s, getCert: %s, serverName:%s, dial:%s", t.insecure, t.caData, t.certData, keyText, t.getCert, t.serverName, t.dial)
+}
+
+func (c *tlsTransportCache) get(config *Config) (http.RoundTripper, error) {
+	key, err := tlsConfigKey(config)
+	if err != nil {
+		return nil, err
+	}
+
+	// Ensure we only create a single transport for the given TLS options
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// See if we already have a custom transport for this config
+	if t, ok := c.transports[key]; ok {
+		return t, nil
+	}
+
+	// Get the TLS options for this client config
+	tlsConfig, err := TLSConfigFor(config)
+	if err != nil {
+		return nil, err
+	}
+	// The options didn't require a custom TLS config
+	if tlsConfig == nil && config.Dial == nil {
+		return http.DefaultTransport, nil
+	}
+
+	dial := config.Dial
+	if dial == nil {
+		dial = (&net.Dialer{
+			Timeout:   30 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).DialContext
+	}
+	// Cache a single transport for these options
+	c.transports[key] = utilnet.SetTransportDefaults(&http.Transport{
+		Proxy:               http.ProxyFromEnvironment,
+		TLSHandshakeTimeout: 10 * time.Second,
+		TLSClientConfig:     tlsConfig,
+		MaxIdleConnsPerHost: idleConnsPerHost,
+		DialContext:         dial,
+	})
+	return c.transports[key], nil
+}
+
+// tlsConfigKey returns a unique key for tls.Config objects returned from TLSConfigFor
+func tlsConfigKey(c *Config) (tlsCacheKey, error) {
+	// Make sure ca/key/cert content is loaded
+	if err := loadTLSFiles(c); err != nil {
+		return tlsCacheKey{}, err
+	}
+	return tlsCacheKey{
+		insecure:   c.TLS.Insecure,
+		caData:     string(c.TLS.CAData),
+		certData:   string(c.TLS.CertData),
+		keyData:    string(c.TLS.KeyData),
+		getCert:    fmt.Sprintf("%p", c.TLS.GetCert),
+		serverName: c.TLS.ServerName,
+		dial:       fmt.Sprintf("%p", c.Dial),
+	}, nil
+}