live-studio-audience/cmd/server/main.go

126 lines
2.3 KiB
Go

package main
import (
"context"
"encoding/base64"
"errors"
"flag"
"fmt"
"log"
"net/http"
"os"
"os/signal"
"syscall"
"golang.org/x/time/rate"
)
type Config struct {
Addr string
RPS int
}
type Handler struct {
cfg Config
limiter *rate.Limiter
}
type Session struct {
User struct {
ID string
Name string
}
}
func main() {
ctx, can := signal.NotifyContext(context.Background(), syscall.SIGINT)
defer can()
if err := run(ctx); err != nil {
panic(err)
}
}
func run(ctx context.Context) error {
cfg, err := newConfig()
if err != nil {
return err
}
return runHTTP(ctx, cfg)
}
func newConfig() (Config, error) {
cfg := Config{}
fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
fs.StringVar(&cfg.Addr, "addr", ":8080", "address to listen on")
fs.IntVar(&cfg.RPS, "rps", 100, "requests per second to serve")
err := fs.Parse(os.Args[1:])
return cfg, err
}
func (cfg Config) NewHandler() Handler {
return Handler{
cfg: cfg,
limiter: rate.NewLimiter(rate.Limit(cfg.RPS), 10),
}
}
func (s Session) Empty() bool {
return s == (Session{})
}
func runHTTP(ctx context.Context, cfg Config) error {
server := &http.Server{
Addr: cfg.Addr,
Handler: cfg.NewHandler(),
}
go func() {
<-ctx.Done()
server.Close()
}()
log.Println("listening on", cfg.Addr)
if err := server.ListenAndServe(); err != nil && ctx.Err() == nil {
return err
}
return nil
}
func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if err := h.serveHTTP(w, r); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
func (h Handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
h.limiter.Wait(r.Context())
session, err := h.auth(r)
if err != nil {
return err
}
if session.Empty() {
w.Header().Set("WWW-Authenticate", "Basic realm=xyz")
w.WriteHeader(http.StatusUnauthorized)
w.Write([]byte(`IDENTIFY YOURSELF!`))
return nil
}
return h.handle(session, w, r)
}
func (h Handler) auth(r *http.Request) (Session, error) {
user, pass, ok := r.BasicAuth()
if !ok {
return Session{}, nil
}
session := Session{}
session.User.ID = base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", user, pass)))
session.User.Name = user
return session, nil
}
func (h Handler) handle(session Session, w http.ResponseWriter, r *http.Request) error {
return errors.New("not impl")
}