heruvym/middleware/http_middleware.go

package middleware

import (
	"bitbucket.org/skeris/profile/dal"
	"bitbucket.org/skeris/profile/errors"
	"bitbucket.org/skeris/profile/jwt_adapter"
	"context"
	"fmt"
	errors2 "github.com/pkg/errors"
	"github.com/themakers/hlog"
	"net/http"
	"strings"
)

// My MiddleWare with gorilla/mux

type Middleware struct {
	logger         hlog.Logger
	mongo          dal.LayerMongoDb
	allowedOrigins string
	allowedRoles   map[string]string // key - path, value - roles
}

func NewMiddleware(
	logger hlog.Logger,
	mongo dal.LayerMongoDb,
	allowedOrigins string,
	allowedRoles map[string]string,
) *Middleware {
	return &Middleware{
		logger:         logger,
		mongo:          mongo,
		allowedOrigins: allowedOrigins,
		allowedRoles:   allowedRoles,
	}
}

func (mw *Middleware) MiddlewareLogger(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		mw.logger.Emit(DebugHttpRequest{Url: r.URL.String()})
		next.ServeHTTP(w, r)
	})
}

func (mw *Middleware) MiddlewareOriginAccess(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if len(r.Header["Origin"]) > 0 {
			if mw.allowedOrigins != "*" && !strings.Contains(mw.allowedOrigins, r.Header["Origin"][0]) {
				mw.logger.Emit(ErrorOriginAccess{Origin: r.Header["Origin"][0], Url: r.URL.String()})
				return
			}
		}
		next.ServeHTTP(w, r)
	})
}

func recFn(rec interface{}) (int, string) {
	var (
		code    int
		message string
	)

	if err, ok := rec.(error); ok {
		if v, ok := errors.IsForbidden(err); ok {
			code = http.StatusForbidden
			message = v.Error()
		} else if v, ok := errors.IsUnauthenticated(err); ok {
			code = http.StatusUnauthorized
			message = v.Error()
		} else {
			code = http.StatusInternalServerError
			message = err.Error()
		}
	} else {
		code = http.StatusInternalServerError
		message = fmt.Sprintf("%v", rec)
	}

	return code, message
}

func (mw *Middleware) MiddlewareRecovery(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if rec := recover(); rec != nil {
				code, message := recFn(rec)
				w.WriteHeader(code)
				if _, err := fmt.Fprint(w, message); err != nil {
					mw.logger.Emit(ErrorWritingPanicResponse{Err: err})
				}
				mw.logger.Emit(ErrorPanicInHttpHandler{
					Code:      code,
					Message:   message,
					Recovered: rec,
				})
			}
		}()
		next.ServeHTTP(w, r)
	})
}

func (mw *Middleware) MiddlewareJwt(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Escape GET requests
		if r.Method == http.MethodGet {
			next.ServeHTTP(w, r)
			return
		}

		if len(r.Header[jwt_adapter.DefaultHeaderKey]) <= 0 {
			mw.logger.Emit(ErrorJwtAccess{Err: errors2.New(jwt_adapter.DefaultHeaderKey + "header missing")})
			w.WriteHeader(http.StatusUnauthorized)
			return
		}

		token := r.Header[jwt_adapter.DefaultHeaderKey][0]
		token = strings.Replace(token, "Bearer ", "", -1)

		adapter, err := jwt_adapter.Decode(token)

		if err != nil {
			mw.logger.Emit(ErrorJwtAccess{Err: err})
			w.WriteHeader(http.StatusUnauthorized)
			return
		}

		err = setJwtHeader(adapter, w, mw.logger)
		if err != nil {
			mw.logger.Emit(ErrorJwtAccess{Err: err})
			w.WriteHeader(http.StatusUnauthorized)
			return
		}

		ctx := context.WithValue(r.Context(), "JWT", adapter)
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

func getJwtUserId(r *http.Request) (string, error) {
	if jwtAdapter, ok := r.Context().Value("JWT").(*jwt_adapter.JwtAdapter); ok {
		return jwtAdapter.User, nil
	}

	return "", errors2.New("no token in context")
}

func (mw *Middleware) MiddlewareRoleAccess(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Если доступ по роли задан
		if allowedRoles, ok := mw.allowedRoles[r.URL.Path]; ok {

			// Если роли не указаны
			if allowedRoles == "" {
				next.ServeHTTP(w, r)
				return
			}

			id, err := getJwtUserId(r)

			if err != nil {
				mw.logger.Emit(ErrorRoleAccess{Err: err})
				http.Error(w, "internal server error", http.StatusInternalServerError)
				return
			}

			role, err := mw.mongo.GetProfileRole(r.Context(), id)

			if err != nil {
				mw.logger.Emit(ErrorRoleAccess{Err: err})
				http.Error(w, "internal server error", http.StatusInternalServerError)
				return
			}

			// Если у пользователя не задана роль - блокируем доступ
			if role == "" {
				err = errors.UserHaveNoRole("User have no role")
				mw.logger.Emit(ErrorRoleAccess{err})
				http.Error(w, err.Error(), http.StatusForbidden)
				return
			}

			// Если указан астериск - доступ имеет любая роль
			if !(allowedRoles == "*" || strings.Contains(allowedRoles, role)) {
				err = errors.UserHaveNoRole("User role not allowed")
				mw.logger.Emit(ErrorRoleAccess{err})
				http.Error(w, err.Error(), http.StatusForbidden)
				return
			}
		}

		next.ServeHTTP(w, r)
	})
}

// MiddlewareJwtPlug jwt заглушка для отладки кода, удалить в релизе
func (mw *Middleware) MiddlewareJwtPlug(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		adapter := jwt_adapter.JwtAdapter{ID: "604b79aced1d431b9e911f56"}
		adapter.Init()
		adapter.SetUserID("604b79aced1d431b9e911f56")
		ctx := context.WithValue(r.Context(), "JWT", &adapter)

		next.ServeHTTP(w, r.WithContext(ctx))
	})
}