I have my own domain with web services written in Go. I am using the inbuilt Go web server, without Nginx or Apache in front.
I would like to start serving over HTTPS and I realized Let's Encrypt is just about to become THE WAY for doing that.
Can anyone share the whole setup procedure for configuring a Go app running on a Linux server?
This is the minimal automatic setup of an HTTPS server using Go and Let's Encrypt certificates I have found:
package main
import (
"crypto/tls"
"log"
"net/http"
"golang.org/x/crypto/acme/autocert"
)
func main() {
certManager := autocert.Manager{
Prompt: autocert.AcceptTOS,
HostPolicy: autocert.HostWhitelist("example.com"), //Your domain here
Cache: autocert.DirCache("certs"), //Folder for storing certificates
}
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Hello world"))
})
server := &http.Server{
Addr: ":https",
TLSConfig: &tls.Config{
GetCertificate: certManager.GetCertificate,
},
}
go http.ListenAndServe(":http", certManager.HTTPHandler(nil))
log.Fatal(server.ListenAndServeTLS("", "")) //Key and cert are coming from Let's Encrypt
}
More information on the autocert package: link
EDIT: Needed to make http available because of letsencrypt security issue, read more here. As a bonus of this fix we now have http-->https redirect. The old example will continue to work if you have already received certificates on it, but it will break for new sites.