add web gui

cmd/web/server/middlewares.go

@@ -0,0 +1,63 @@
+package server
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+func recoverMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer func() {
+			err := recover()
+			if err != nil {
+				internalServerError(w, r)
+			}
+		}()
+		next.ServeHTTP(w, r)
+	})
+}
+
+// BasicAuth implements a simple middleware handler for adding basic http auth to a route.
+func BasicAuth(realm string, creds map[string]string) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			user, pass, ok := r.BasicAuth()
+			if !ok {
+				basicAuthFailed(w, r, realm)
+				return
+			}
+
+			credPass := creds[user]
+			if err := bcrypt.CompareHashAndPassword([]byte(credPass), []byte(pass)); err != nil {
+				basicAuthFailed(w, r, realm)
+				return
+			}
+
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+func basicAuthFailed(w http.ResponseWriter, r *http.Request, realm string) {
+	unauthorized(realm, w, r)
+}
+
+func unauthorized(realm string, w http.ResponseWriter, r *http.Request) {
+	w.Header().Add("WWW-Authenticate", fmt.Sprintf(`Basic realm="%s"`, realm))
+	w.WriteHeader(http.StatusUnauthorized)
+	_, err := w.Write([]byte(UnauthorizedErrorHTMLPage))
+	if err != nil {
+		log.Println(err)
+	}
+}
+
+func internalServerError(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusInternalServerError)
+	_, err := w.Write([]byte(InternalServerErrorHTMLPage))
+	if err != nil {
+		log.Println(err)
+	}
+}