apiserver: use fixtures for self-signed certs in test server

Kubernetes-commit: 7deccb5b7a7c5224d3d90e1391dd22b2d1f1b9b9

util/cert/cert.go

@@ -27,9 +27,12 @@ import (
 	"encoding/pem"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"math"
 	"math/big"
 	"net"
+	"path"
+	"strings"
 	"time"
 )
 
@@ -136,8 +139,38 @@ func MakeEllipticPrivateKeyPEM() ([]byte, error) {
 
 // GenerateSelfSignedCertKey creates a self-signed certificate and key for the given host.
 // Host may be an IP or a DNS name
-// You may also specify additional subject alt names (either ip or dns names) for the certificate
+// You may also specify additional subject alt names (either ip or dns names) for the certificate.
 func GenerateSelfSignedCertKey(host string, alternateIPs []net.IP, alternateDNS []string) ([]byte, []byte, error) {
+	return GenerateSelfSignedCertKeyWithFixtures(host, alternateIPs, alternateDNS, "")
+}
+
+// GenerateSelfSignedCertKeyWithFixtures creates a self-signed certificate and key for the given host.
+// Host may be an IP or a DNS name. You may also specify additional subject alt names (either ip or dns names)
+// for the certificate.
+//
+// If fixtureDirectory is non-empty, it is a directory path which can contain pre-generated certs. The format is:
+// <host>_<ip>-<ip>_<alternateDNS>-<alternateDNS>.crt
+// <host>_<ip>-<ip>_<alternateDNS>-<alternateDNS>.key
+// Certs/keys not existing in that directory are created.
+func GenerateSelfSignedCertKeyWithFixtures(host string, alternateIPs []net.IP, alternateDNS []string, fixtureDirectory string) ([]byte, []byte, error) {
+	validFrom := time.Now().Add(-time.Hour) // valid an hour earlier to avoid flakes due to clock skew
+	maxAge := time.Hour * 24 * 365          // one year self-signed certs
+
+	baseName := fmt.Sprintf("%s_%s_%s", host, strings.Join(ipsToStrings(alternateIPs), "-"), strings.Join(alternateDNS, "-"))
+	certFixturePath := path.Join(fixtureDirectory, baseName+".crt")
+	keyFixturePath := path.Join(fixtureDirectory, baseName+".key")
+	if len(fixtureDirectory) > 0 {
+		cert, err := ioutil.ReadFile(certFixturePath)
+		if err == nil {
+			key, err := ioutil.ReadFile(keyFixturePath)
+			if err == nil {
+				return cert, key, nil
+			}
+			return nil, nil, fmt.Errorf("cert %s can be read, but key %s cannot: %v", certFixturePath, keyFixturePath, err)
+		}
+		maxAge = 100 * time.Hour * 24 * 365 // 100 years fixtures
+	}
+
 	caKey, err := rsa.GenerateKey(cryptorand.Reader, 2048)
 	if err != nil {
 		return nil, nil, err
@@ -148,8 +181,8 @@ func GenerateSelfSignedCertKey(host string, alternateIPs []net.IP, alternateDNS
 		Subject: pkix.Name{
 			CommonName: fmt.Sprintf("%s-ca@%d", host, time.Now().Unix()),
 		},
-		NotBefore: time.Now(),
+		NotBefore: validFrom,
-		NotAfter:  time.Now().Add(time.Hour * 24 * 365),
+		NotAfter:  validFrom.Add(maxAge),
 
 		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
 		BasicConstraintsValid: true,
@@ -176,8 +209,8 @@ func GenerateSelfSignedCertKey(host string, alternateIPs []net.IP, alternateDNS
 		Subject: pkix.Name{
 			CommonName: fmt.Sprintf("%s@%d", host, time.Now().Unix()),
 		},
-		NotBefore: time.Now(),
+		NotBefore: validFrom,
-		NotAfter:  time.Now().Add(time.Hour * 24 * 365),
+		NotAfter:  validFrom.Add(maxAge),
 
 		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
 		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
@@ -213,6 +246,15 @@ func GenerateSelfSignedCertKey(host string, alternateIPs []net.IP, alternateDNS
 		return nil, nil, err
 	}
 
+	if len(fixtureDirectory) > 0 {
+		if err := ioutil.WriteFile(certFixturePath, certBuffer.Bytes(), 0644); err != nil {
+			return nil, nil, fmt.Errorf("failed to write cert fixture to %s: %v", certFixturePath, err)
+		}
+		if err := ioutil.WriteFile(keyFixturePath, keyBuffer.Bytes(), 0644); err != nil {
+			return nil, nil, fmt.Errorf("failed to write key fixture to %s: %v", certFixturePath, err)
+		}
+	}
+
 	return certBuffer.Bytes(), keyBuffer.Bytes(), nil
 }
 
@@ -243,3 +285,11 @@ func FormatCert(c *x509.Certificate) string {
 	}
 	return res
 }
+
+func ipsToStrings(ips []net.IP) []string {
+	ss := make([]string, 0, len(ips))
+	for _, ip := range ips {
+		ss = append(ss, ip.String())
+	}
+	return ss
+}