package main
import (
"bytes"
"context"
"crypto/hmac"
"crypto/sha1"
"crypto/tls"
"encoding/hex"
"flag"
"fmt"
"log"
"net/http"
"os"
"os/exec"
"path"
"strconv"
"strings"
"syscall"
"compress/gzip"
"io"
"io/ioutil"
"sync"
"github.com/sevlyar/go-daemon"
gfm "github.com/shurcooL/github_flavored_markdown"
"github.com/shurcooL/github_flavored_markdown/gfmstyle"
//blackfriday "gopkg.in/russross/blackfriday.v2"
)
// code copied from https://gist.github.com/CJEnright/bc2d8b8dc0c1389a9feeddb110f822d7
var gzPool = sync.Pool{
New: func() interface{} {
w := gzip.NewWriter(ioutil.Discard)
return w
},
}
type gzipResponseWriter struct {
io.Writer
http.ResponseWriter
}
func (w *gzipResponseWriter) WriteHeader(status int) {
w.Header().Del("Content-Length")
w.ResponseWriter.WriteHeader(status)
}
func (w *gzipResponseWriter) Write(b []byte) (int, error) {
return w.Writer.Write(b)
}
func Gzip(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
next.ServeHTTP(w, r)
return
}
w.Header().Set("Content-Encoding", "gzip")
gz := gzPool.Get().(*gzip.Writer)
defer gzPool.Put(gz)
gz.Reset(w)
defer gz.Close()
next.ServeHTTP(&gzipResponseWriter{ResponseWriter: w, Writer: gz}, r)
})
}
var (
signal = flag.String("s", "", `send signal to the daemon
quit — graceful shutdown
stop — fast shutdown
reload — reloading the configuration file`)
devmode = flag.Bool("dev_mode", false, "whether this server should run in developer mode or not")
)
const DEBUG = false
const HOME_DIR = "/home/kelvin/"
const DOMAIN_NAME = "threefortiethofonehamster.com"
const HTML_HEADER = `
%s | %s
`
const HTML_FOOTER = `
`
func serveMarkdown(w http.ResponseWriter, r *http.Request, paths ...string) {
bs := make([][]byte, 0, len(paths))
for _, path := range paths {
if b, err := ioutil.ReadFile(path); err != nil {
w.WriteHeader(404)
w.Write([]byte(fmt.Sprintf("file %s not found", path)))
return
} else {
bs = append(bs, b)
}
}
w.Header().Add("Content-Type", "text/html; charset=utf-8")
title := ""
if s := bytes.Index(bs[0], []byte("# ")); s != -1 {
t := bs[0][s+2:]
if e := bytes.Index(t, []byte("\n")); e != -1 {
t = t[:e]
title = string(t)
}
}
w.Write([]byte(fmt.Sprintf(HTML_HEADER, string(title), r.Host)))
for _, b := range bs {
html := gfm.Markdown(b)
w.Write(html)
}
w.Write([]byte(HTML_FOOTER))
}
func rootHandler(w http.ResponseWriter, r *http.Request) {
if r.Method == "GET" {
if r.URL.Path == "/" {
serveMarkdown(w, r, "static/intro.md", "static/projects.md", "static/builds.md")
} else if strings.HasSuffix(r.URL.Path, ".md") {
if strings.Contains(r.URL.Path, "..") {
w.WriteHeader(403)
w.Write([]byte("\"..\" forbidden in URL"))
return
}
filepath := "static" + r.URL.Path
serveMarkdown(w, r, filepath)
} else {
http.ServeFile(w, r, "static"+r.URL.Path)
}
} else {
w.Write([]byte("unimplemented!"))
}
}
var (
shutdown chan struct{} = make(chan struct{})
serverShutdown chan struct{} = make(chan struct{})
)
func main() {
flag.Parse()
daemon.AddCommand(daemon.StringFlag(signal, "quit"), syscall.SIGQUIT, termHandler)
daemon.AddCommand(daemon.StringFlag(signal, "stop"), syscall.SIGTERM, termHandler)
daemon.AddCommand(daemon.StringFlag(signal, "reload"), syscall.SIGHUP, reloadHandler)
execName := path.Base(os.Args[0])
cntxt := &daemon.Context{
PidFileName: "/tmp/" + execName + "-pid",
PidFilePerm: 0644,
LogFileName: "/tmp/" + execName + "-log",
LogFilePerm: 0640,
WorkDir: HOME_DIR + execName + "/",
Umask: 027,
}
if DEBUG {
cntxt.WorkDir = "."
}
// TODO: figure out the daemonizing stuff
if len(daemon.ActiveFlags()) > 0 {
d, err := cntxt.Search()
if err != nil {
log.Fatalln("Unable to send signal to daemon:", err)
}
daemon.SendCommands(d)
return
}
d, err := cntxt.Reborn()
if err != nil {
log.Fatalln(err)
}
if d != nil {
return
}
defer cntxt.Release()
var redirect http.Server
var srv http.Server
go startRedirectServer(&redirect)
go startServer(&srv)
go func() {
<-shutdown
log.Println("shutting down server...")
if err := srv.Shutdown(context.Background()); err != nil {
log.Printf("server shutdown error: %v\n", err)
}
if err = redirect.Shutdown(context.Background()); err != nil {
log.Printf("redirect shutdown error: %v\n", err)
}
}()
err = daemon.ServeSignals()
if err != nil {
log.Println("Error: ", err)
}
log.Println("server terminated")
}
func termHandler(sig os.Signal) error {
log.Printf("sending shutdown signal...")
close(shutdown)
return daemon.ErrStop
}
func reloadHandler(sig os.Signal) error {
log.Printf("[WARN] reloading not supported yet")
return nil
}
func readWebhookKey() []byte {
b, err := ioutil.ReadFile("webhook_secret")
if err != nil {
log.Printf("[ERR] webhook key not found, webhook updates will not work!")
return nil
}
/*
ret := make([]byte, hex.DecodedLen(len(b)))
// skip the ending 0x0a
rl, err2 := hex.Decode(ret, b[:len(b)-1])
if err2 != nil {
log.Printf("[ERR] unable to decode webhook key! %v %s", b, err2)
return nil
}
*/
return b[:len(b)-1]
}
var transportNoTlsVerify = http.Transport{
TLSClientConfig: &tls.Config{
InsecureSkipVerify: true,
},
}
// copied from https://stackoverflow.com/questions/34724160/go-http-send-incoming-http-request-to-an-other-server-using-client-do
func forwardRequest(port int, proxyScheme string) func(http.ResponseWriter, *http.Request) {
proxyHost := "0.0.0.0" + ":" + strconv.Itoa(port)
return func(w http.ResponseWriter, req *http.Request) {
// we need to buffer the body if we want to read it here and send it
// in the request.
body, err := ioutil.ReadAll(req.Body)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
// you can reassign the body if you need to parse it as multipart
req.Body = ioutil.NopCloser(bytes.NewReader(body))
// create a new url from the raw RequestURI sent by the client
url := fmt.Sprintf("%s://%s%s", proxyScheme, proxyHost, req.RequestURI)
proxyReq, err := http.NewRequest(req.Method, url, bytes.NewReader(body))
// We may want to filter some headers, otherwise we could just use a shallow copy
// proxyReq.Header = req.Header
proxyReq.Header = make(http.Header)
for h, val := range req.Header {
proxyReq.Header[h] = val
}
resp, err := (&http.Client{Transport: &transportNoTlsVerify}).Do(proxyReq)
if err != nil {
http.Error(w, err.Error(), http.StatusBadGateway)
return
}
defer resp.Body.Close()
// legacy code
}
}
func startServer(srv *http.Server) {
log.Print("installing handlers")
webhookKey := readWebhookKey()
serveMux := http.NewServeMux()
if !*devmode {
serveMux.HandleFunc("dev."+DOMAIN_NAME+"/", forwardRequest(8444, "https"))
}
serveMux.HandleFunc("/", rootHandler)
//serveMux.Handle("/certbot/", http.StripPrefix("/certbot/", http.FileServer(http.Dir("./certbot-tmp"))))
serveMux.Handle("/gfm/", http.StripPrefix("/gfm", http.FileServer(gfmstyle.Assets)))
serveMux.Handle("/resume/", http.StripPrefix("/resume", http.FileServer(http.Dir("resume/"))))
serveMux.HandleFunc("/main.css", func(w http.ResponseWriter, r *http.Request) { http.ServeFile(w, r, "main.css") })
if webhookKey != nil {
log.Print("web hook found")
serveMux.HandleFunc("/update", func(w http.ResponseWriter, r *http.Request) {
if r.Method != "POST" {
w.WriteHeader(403)
w.Write([]byte("invalid request type"))
return
}
signature := r.Header.Get("X-Hub-Signature")
if len(signature) == 0 {
w.WriteHeader(403)
w.Write([]byte("invalid request"))
return
}
payload, e := ioutil.ReadAll(r.Body)
if e != nil {
w.WriteHeader(403)
w.Write([]byte("unable to read body: " + e.Error()))
return
}
mac := hmac.New(sha1.New, webhookKey)
mac.Write(payload)
expected := mac.Sum(nil)
signatureDec := make([]byte, hex.DecodedLen(len(signature)))
// skip the "sha1=" part
sdl, e2 := hex.Decode(signatureDec, []byte(signature)[5:])
if e2 != nil {
w.WriteHeader(403)
w.Write([]byte("unable to read signature"))
return
}
signatureDec = signatureDec[:sdl]
if !hmac.Equal(expected, signatureDec) {
log.Print("webhook hmac match failed; expected %v found %v", expected, signatureDec)
w.WriteHeader(403)
w.Write([]byte("invalid request"))
return
}
// TODO parse payload
pullCmd := exec.Command("git", "pull")
pullCmd.Dir = "./static/"
_ = pullCmd.Run()
w.Write([]byte("success"))
})
}
if *devmode {
srv.Addr = ":8444"
srv.Handler = serveMux
} else {
srv.Addr = ":8443"
srv.Handler = Gzip(serveMux)
}
log.Print("starting server")
if !DEBUG {
log.Fatal(srv.ListenAndServeTLS("/etc/letsencrypt/live/"+DOMAIN_NAME+"/fullchain.pem",
"/etc/letsencrypt/live/"+DOMAIN_NAME+"/privkey.pem"))
} else {
log.Fatal(srv.ListenAndServe())
}
close(serverShutdown)
}
func startRedirectServer(srv *http.Server) {
serveMux := http.NewServeMux()
// copied from https://gist.github.com/d-schmidt/587ceec34ce1334a5e60
if !*devmode {
serveMux.HandleFunc("dev."+DOMAIN_NAME+"/", forwardRequest(8081, "http"))
}
serveMux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
target := "https://" + req.Host + req.URL.Path
if len(req.URL.RawQuery) > 0 {
target += "?" + req.URL.RawQuery
}
http.Redirect(w, req, target, http.StatusTemporaryRedirect)
})
if *devmode {
srv.Addr = ":8081"
} else {
srv.Addr = ":8080"
}
srv.Handler = serveMux
log.Print("starting server")
log.Fatal(srv.ListenAndServe())
close(serverShutdown)
}