Merge pull request #36068 from sttts/sttts-old-self-signed-cn

Automatic merge from submit-queue

Restore old apiserver cert CN

This patch got lost during rebase of https://github.com/kubernetes/kubernetes/pull/35109:

- set `host@<unix-timestamp>` as CN in self-signed apiserver certs
- skip non-domain CN in getNamedCertificateMap

pkg/util/cert/cert.go

@@ -138,7 +138,7 @@ func GenerateSelfSignedCertKey(host string, alternateIPs []net.IP, alternateDNS
 	template := x509.Certificate{
 		SerialNumber: big.NewInt(1),
 		Subject: pkix.Name{
-			CommonName: host,
+			CommonName: fmt.Sprintf("%s@%d", host, time.Now().Unix()),
 		},
 		NotBefore: time.Now(),
 		NotAfter:  time.Now().Add(time.Hour * 24 * 365),