Remove the apiserver-boot dependency for generate certificate.

[medinatiger]

We should remove the need to run apiserver-boot to generate certificate for running ext api server. The logs of apiserver-boot shows the required openssl commands to do the job.

[medinatiger]

Thanks the idea from @mrIncompetent
//import "k8s.io/client-go/util/cert/triple"
caKeyPair, err := triple.NewCA("root-ca.example.com")
if err != nil {
return fmt.Errorf("failed to create root-ca: %v", err)
}

apiserverKeypair, err := triple.NewServerKeyPair(caKeyPair, "apiserver.example.com", "kubernetes", "default", "cluster.local", []string{"10.10.10.1"}, []string{"some-other-hostname"})
if err != nil {
return fmt.Errorf("failed to create apiserver key pair: %v", err)
}

//to get it pem encoded as byte slice:
// import "k8s.io/client-go/util/cert"
b1 := cert.EncodePrivateKeyPEM(apiserverKeypair.Key)
b2 := cert.EncodeCertPEM(apiserverKeypair.Cert)

[rsdcastro]

This issue was moved to kubernetes-sigs/cluster-api#36