gpaste/middleware.go

package gpaste

import (
	"context"
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/go-chi/chi/v5/middleware"
)

type authCtxKey int

const (
	authCtxUsername authCtxKey = iota
)

func (s *HTTPServer) MiddlewareAccessLogger(next http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)
		t1 := time.Now()

		reqID := middleware.GetReqID(r.Context())

		defer func() {
			s.AccessLogger.Infow(r.Method,
				"path", r.URL.Path,
				"status", ww.Status(),
				"written", ww.BytesWritten(),
				"remote_addr", r.RemoteAddr,
				"processing_time_ms", time.Since(t1).Milliseconds(),
				"req_id", reqID)
		}()

		next.ServeHTTP(ww, r)
	}
	return http.HandlerFunc(fn)
}

func (s *HTTPServer) MiddlewareAuthentication(next http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		reqID := middleware.GetReqID(r.Context())
		header := r.Header.Get("Authorization")
		if header == "" {
			s.Logger.Debugw("Request has no auth header.", "req_id", reqID)
			next.ServeHTTP(w, r)
			return
		}

		splitHeader := strings.Split(header, "Bearer ")
		if len(splitHeader) != 2 {
			s.Logger.Debugw("Request has invalid token.", "req_id", reqID)
			next.ServeHTTP(w, r)
			return
		}
		token := splitHeader[1]

		claims, err := s.Auth.ValidateToken(token)
		if err != nil {
			s.Logger.Debugw("Request has invalid token.", "req_id", reqID)
			next.ServeHTTP(w, r)
			return
		}

		ctx := context.WithValue(r.Context(), authCtxUsername, claims.Subject)
		withCtx := r.WithContext(ctx)
		s.Logger.Debugw("Request is authenticated.", "req_id", reqID, "username", claims.Subject)

		next.ServeHTTP(w, withCtx)
	}

	return http.HandlerFunc(fn)
}

func UsernameFromRequest(r *http.Request) (string, error) {
	rawUsername := r.Context().Value(authCtxUsername)
	if rawUsername == nil {

		return "", fmt.Errorf("no username")
	}
	username, ok := rawUsername.(string)
	if !ok {
		return "", fmt.Errorf("no username")
	}
	return username, nil
}