Merge pull request #85004 from deads2k/dynamic-agg-cert

dynamic reload cluster authentication info for aggregated API servers

Kubernetes-commit: 02af1dd62c4842e20e2ee7337edf032327b1c8ed

Godeps/Godeps.json

@@ -348,11 +348,11 @@
 		},
 		{
 			"ImportPath": "k8s.io/api",
-			"Rev": "37fc98278a4b"
+			"Rev": "40f4bbc2b486"
 		},
 		{
 			"ImportPath": "k8s.io/apimachinery",
-			"Rev": "d496f1036126"
+			"Rev": "3db02fd2eea7"
 		},
 		{
 			"ImportPath": "k8s.io/gengo",

go.mod

@@ -28,8 +28,8 @@ require (
 	golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45
 	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4
 	google.golang.org/appengine v1.5.0 // indirect
-	k8s.io/api v0.0.0-20191114100032-37fc98278a4b
+	k8s.io/api v0.0.0-20191114100036-40f4bbc2b486
-	k8s.io/apimachinery v0.0.0-20191114095527-d496f1036126
+	k8s.io/apimachinery v0.0.0-20191114095528-3db02fd2eea7
 	k8s.io/klog v1.0.0
 	k8s.io/utils v0.0.0-20191030222137-2b95a09bc58d
 	sigs.k8s.io/yaml v1.1.0
@@ -38,6 +38,6 @@ require (
 replace (
 	golang.org/x/sys => golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a
 	golang.org/x/tools => golang.org/x/tools v0.0.0-20190821162956-65e3620a7ae7
-	k8s.io/api => k8s.io/api v0.0.0-20191114100032-37fc98278a4b
+	k8s.io/api => k8s.io/api v0.0.0-20191114100036-40f4bbc2b486
-	k8s.io/apimachinery => k8s.io/apimachinery v0.0.0-20191114095527-d496f1036126
+	k8s.io/apimachinery => k8s.io/apimachinery v0.0.0-20191114095528-3db02fd2eea7
 )

go.sum

@@ -191,8 +191,8 @@ gopkg.in/yaml.v2 v2.2.4 h1:/eiJrUcujPVeJ3xlSWaiNi3uSVmDGBK1pDHUHAnao1I=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
-k8s.io/api v0.0.0-20191114100032-37fc98278a4b/go.mod h1:8svLRMiLwQReMTycutfjsaQ0ackWIf8HCT4UcixYLjI=
+k8s.io/api v0.0.0-20191114100036-40f4bbc2b486/go.mod h1:IM5ceavki8HjRhUlaRYP3oGw0J/hbXKiKiSqS5AR728=
-k8s.io/apimachinery v0.0.0-20191114095527-d496f1036126/go.mod h1:+6CX7hP4aLfX2sb91JYDMIp0VqDSog2kZu0BHe+lP+s=
+k8s.io/apimachinery v0.0.0-20191114095528-3db02fd2eea7/go.mod h1:+6CX7hP4aLfX2sb91JYDMIp0VqDSog2kZu0BHe+lP+s=
 k8s.io/gengo v0.0.0-20190128074634-0689ccc1d7d6/go.mod h1:ezvh/TsK7cY6rbqRK0oQQ8IAqLxYwwyPxAX1Pzy0ii0=
 k8s.io/klog v0.0.0-20181102134211-b9b56d5dfc92/go.mod h1:Gq+BEi5rUBO/HRz0bTSXDUcqjScdoY3a9IHpCEIOOfk=
 k8s.io/klog v0.3.0/go.mod h1:Gq+BEi5rUBO/HRz0bTSXDUcqjScdoY3a9IHpCEIOOfk=

util/cert/server_inspection.go

@@ -0,0 +1,97 @@
+/*
+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 cert
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"net/url"
+	"strings"
+)
+
+// GetClientCANames gets the CA names for client certs that a server accepts.  This is useful when inspecting the
+// state of particular servers.  apiHost is "host:port"
+func GetClientCANames(apiHost string) ([]string, error) {
+	// when we run this the second time, we know which one we are expecting
+	acceptableCAs := []string{}
+	tlsConfig := &tls.Config{
+		InsecureSkipVerify: true, // this is insecure to always get to the GetClientCertificate
+		GetClientCertificate: func(hello *tls.CertificateRequestInfo) (*tls.Certificate, error) {
+			acceptableCAs = []string{}
+			for _, curr := range hello.AcceptableCAs {
+				acceptableCAs = append(acceptableCAs, string(curr))
+			}
+			return &tls.Certificate{}, nil
+		},
+	}
+
+	conn, err := tls.Dial("tcp", apiHost, tlsConfig)
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	return acceptableCAs, nil
+}
+
+// GetClientCANamesForURL is GetClientCANames against a URL string like we use in kubeconfigs
+func GetClientCANamesForURL(kubeConfigURL string) ([]string, error) {
+	apiserverURL, err := url.Parse(kubeConfigURL)
+	if err != nil {
+		return nil, err
+	}
+	return GetClientCANames(apiserverURL.Host)
+}
+
+// GetServingCertificates returns the x509 certs used by a server as certificates and pem encoded bytes.
+// The serverName is optional for specifying a different name to get SNI certificates.  apiHost is "host:port"
+func GetServingCertificates(apiHost, serverName string) ([]*x509.Certificate, [][]byte, error) {
+	tlsConfig := &tls.Config{
+		InsecureSkipVerify: true, // this is insecure so that we always get connected
+	}
+	// if a name is specified for SNI, set it.
+	if len(serverName) > 0 {
+		tlsConfig.ServerName = serverName
+	}
+
+	conn, err := tls.Dial("tcp", apiHost, tlsConfig)
+	if err != nil {
+		return nil, nil, err
+	}
+	conn.Close()
+
+	peerCerts := conn.ConnectionState().PeerCertificates
+	peerCertBytes := [][]byte{}
+	for _, a := range peerCerts {
+		actualCert, err := EncodeCertificates(a)
+		if err != nil {
+			return nil, nil, err
+		}
+		peerCertBytes = append(peerCertBytes, []byte(strings.TrimSpace(string(actualCert))))
+	}
+
+	return peerCerts, peerCertBytes, err
+}
+
+// GetServingCertificatesForURL is GetServingCertificates against a URL string like we use in kubeconfigs
+func GetServingCertificatesForURL(kubeConfigURL, serverName string) ([]*x509.Certificate, [][]byte, error) {
+	apiserverURL, err := url.Parse(kubeConfigURL)
+	if err != nil {
+		return nil, nil, err
+	}
+	return GetServingCertificates(apiserverURL.Host, serverName)
+}