158 lines
3.1 KiB
Go
158 lines
3.1 KiB
Go
package main
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import (
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"context"
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"embed"
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"encoding/base64"
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"errors"
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"flag"
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"fmt"
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"io/fs"
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"log"
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"net/http"
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"os"
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"os/signal"
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"strings"
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"syscall"
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"golang.org/x/time/rate"
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)
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type Config struct {
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Addr string
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RPS int
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}
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type Handler struct {
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cfg Config
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limiter *rate.Limiter
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}
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type Session struct {
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User struct {
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ID string
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Name string
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}
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}
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func main() {
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ctx, can := signal.NotifyContext(context.Background(), syscall.SIGINT)
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defer can()
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if err := run(ctx); err != nil {
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panic(err)
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}
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}
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func run(ctx context.Context) error {
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cfg, err := newConfig()
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if err != nil {
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return err
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}
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return runHTTP(ctx, cfg)
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}
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func newConfig() (Config, error) {
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cfg := Config{}
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fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
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fs.StringVar(&cfg.Addr, "addr", ":8080", "address to listen on")
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fs.IntVar(&cfg.RPS, "rps", 100, "requests per second to serve")
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err := fs.Parse(os.Args[1:])
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return cfg, err
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}
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func (cfg Config) NewHandler() Handler {
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return Handler{
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cfg: cfg,
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limiter: rate.NewLimiter(rate.Limit(cfg.RPS), 10),
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}
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}
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func (s Session) Empty() bool {
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return s == (Session{})
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}
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func runHTTP(ctx context.Context, cfg Config) error {
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server := &http.Server{
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Addr: cfg.Addr,
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Handler: cfg.NewHandler(),
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}
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go func() {
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<-ctx.Done()
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server.Close()
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}()
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log.Println("listening on", cfg.Addr)
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if err := server.ListenAndServe(); err != nil && ctx.Err() == nil {
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return err
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}
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return nil
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}
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func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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if err := h.serveHTTP(w, r); err != nil {
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http.Error(w, err.Error(), http.StatusInternalServerError)
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}
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}
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func (h Handler) serveHTTP(w http.ResponseWriter, r *http.Request) error {
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h.limiter.Wait(r.Context())
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session, err := h.auth(r)
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if err != nil {
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return err
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}
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if session.Empty() {
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w.Header().Set("WWW-Authenticate", "Basic realm=xyz")
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w.WriteHeader(http.StatusUnauthorized)
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w.Write([]byte(`IDENTIFY YOURSELF!`))
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return nil
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}
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return h.handle(session, w, r)
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}
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func (h Handler) auth(r *http.Request) (Session, error) {
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user, pass, ok := r.BasicAuth()
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if !ok {
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return Session{}, nil
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}
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session := Session{}
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session.User.ID = base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", user, pass)))
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session.User.Name = user
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return session, nil
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}
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//go:embed internal/public
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var _public embed.FS
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var public = func() http.FileSystem {
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d, err := fs.Sub(_public, "internal/public")
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if err != nil {
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panic(err)
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}
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return http.FS(d)
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}()
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func (h Handler) handle(session Session, w http.ResponseWriter, r *http.Request) error {
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if !strings.HasPrefix(r.URL.Path, "/api/") {
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http.FileServer(public).ServeHTTP(w, r)
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return nil
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}
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switch r.URL.Path {
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case "/api/v1/question":
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return h.handleAPIV1Question(session, w, r)
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case "/api/v1/answer":
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return h.handleAPIV1Answer(session, w, r)
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}
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http.NotFound(w, r)
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return nil
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}
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func (h Handler) handleAPIV1Question(session Session, w http.ResponseWriter, r *http.Request) error {
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return errors.New("not impl")
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}
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func (h Handler) handleAPIV1Answer(session Session, w http.ResponseWriter, r *http.Request) error {
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return errors.New("not impl")
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}
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