get cert from acme / letsencrypto auto cert manager

getacme.go

// get cert from acme / letsencrypto auto cert manager
// usage: go run getacme.go hostname
package main

import (
	"crypto/tls"
	"crypto/x509"
	"fmt"
	"log"
	"net/http"

	"github.com/grantae/certinfo"
	"golang.org/x/crypto/acme/autocert"
)

func main() {
	acm := autocert.Manager{
		Prompt:     autocert.AcceptTOS,
		HostPolicy: autocert.HostWhitelist("test.domain.com"),
		Cache:      autocert.DirCache("cache"),
	}

	go http.ListenAndServe(":8080", acm.HTTPHandler(nil))

	https := &http.Server{
		Addr:      ":8443",
		TLSConfig: &tls.Config{GetCertificate: acm.GetCertificate},
	}
	go https.ListenAndServeTLS("", "")

	cert, err := acm.GetCertificate(&tls.ClientHelloInfo{ServerName: "test.domain.com"})
	if err != nil {
		log.Fatal(err)
	}

	pub, err := x509.ParseCertificate(cert.Certificate[0])
	if err != nil {
		log.Fatal(err)
	}

	txt, err := certinfo.CertificateText(pub)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(txt)
}