Create an X509 certificate with local IP addresses in Golang.

x509-ip.go

/*
template := x509.Certificate{
	...
}
*/

addrs, err := net.InterfaceAddrs()

if err != nil {
	panic(err)
}

for _, addr := range addrs {
	var ip net.IP

	switch v := addr.(type) {
	case *net.IPNet:
		ip = v.IP
	case *net.IPAddr:
		ip = v.IP
	default:
		continue
	}

	template.IPAddresses = append(template.IPAddresses, ip)
	template.DNSNames = append(template.DNSNames, ip.String())
}

/*
der, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
*/